Idea Transcript
Biology
Mrs.Kieliszek
Review for Final Exam General Science Skills: Reading a metric ruler
So : 1 cm = 10 mm
37 mm = 3.7cm
4mm = 0.4cm
Reading a graduated cyclinder
Volume = 55 ml The liquid surface is curved (U-shaped) rather than horizontal due to the relatively strong attractive force between water and glass. (The curved surface is called the meniscus.) As a general rule, the bottom of the meniscus is taken as the liquid level in the cylinder (and any other liquid volume measuring device). Reading off a graph
What grade did Frank get on the third test? First find test number 3 on the horizontal axis. Then move up until you hit the point. You see that Frank got a 100 on the third test.
The Microscope How is the field of view size used to calculate the size of cells viewed through a microscope? By knowing the diameter of the field of view, and having an estimate of the number of cells that would fit across the diameter, you can determine the size of a cell by dividing the diameter by the number of cells. For example: The diameter of the field of view under 100 x total magnification is about 1.5 mm. If there are 10 cells that would fit across the diameter, one cell would be 0.15 mm. (1.5 mm/ 10 = 0.15 mm) The diameter of the field of view under 400x total magnification is approximately 0.375 mm. 1 mm = 1000 um (micrometers) 0.5 mm = 500 um (micrometers) When iodine is added to cells, what part of the cell can you see better? The nucleus of most cells is usually more visible after stain. In plant cells chloroplasts are seen far better as well. Staining a specimen reveals details that are otherwise not easily seen. Putting on a coverslip: Coverslip should be lowered from a 45 degree angle onto the slide to reduce the formation of air bubbles.
Scientific Method: What is the Scientific Method?
It is the steps someone takes to identify a question, develop a hypothesis, design and carry out steps or procedures to test the hypothesis, and document observations and findings to share with someone else.
IdenQfy a problem
Gather InformaQon
Formulate a hypothesis
Design and Experiment
Draw Conclusions
Analyze Data
Record and Organize Data
Steps of the Scientific Method 1.Problem/Question: A problem or question that can be solved through experimentation. EX: Does soil temperature affect plant growth? 2. Observation/Research: Make observations and research your topic of interest. 3. Formulate a Hypothesis (Educated Guess): Predict a possible answer to the problem or question. Using an IF, THEN statement. Example: If soil temperatures rise, then plant growth will increase. 4. Experiment: Develop and follow a procedure. Include a detailed materials list. The outcome must be measurable (quantifiable). 5. Collect and Analyze Results: (DATA) Make Charts/Graphs ,Compare and look for trends & patterns using graphs. 6. Conclusion: Include a statement that accepts or rejects the hypothesis and why. Refer to your data in your explanation. Make recommendations for further study and possible improvements to the procedure. 7. Repeat Experiment : You must repeat the experiment to make it valid. Others must also be able to do your experiment and have the same results. Results and Data **** If your results DO NOT fit (support) your Hypothesis do not change your data. Change the hypothesis and retry your experiment. Independent Variable
The independent variable is the variable that the scientist change or manipulate. The independent, or manipulated variable, is the variable that can be controlled by the experimenter. It usually includes time (dates, minutes, hours), depth (feet, meters), temperature (Celsius).
This variable is ALWAYS graphed on the X axis (horizontal)
Dependent Variable
The dependent, or responding variable, is the variable that is directly affected by the independent variable. It is the result of what happens because of the independent variable. Is the thing being tested in the experiment Changes because of the independent variable “ Depends on the independent variable This variable is ALWAYS graphed on the Y axis (vertical) EX: The amount the plant height changes with different soil temperatures.
Remember!!! Graphing When graphing your data from an experiment always place the independent variable on the X axis (horizontal) and the dependent variable on the Y axis (vertical). Variables: Constant
All the factors in the experiments that are kept the same Everything except the independent variable Keeps the experiment ‘fair’ Ex: amount of sunlight each plant gets, amount of water, type of soil, type of plant, plants are all the same age
Control Group In a scientific experiment, the control is the group that serves as the standard of comparison. The control group is exposed to the same conditions as the experimental group, except for the variable being tested. *** All experiments must have a control group in order to be valid. • •
Valid Experiment
In order for a scientific experiment to be valid it can only have one variable. This variable is the part that is being tested. All other parts of the experiment must remain the same or constant Any experiment that has more than 1 variable cannot prove anything and therefore is invalid.
More Valid/More Accurate
To make an experiment more valid: Increase the number of test subjects(use a large sample size) Repeat the experiment and get the same results You must always use a control group Have other people complete your experiment and get the same results (peer review)
Graphing Rules for Graphing All lines must be equal distance apart. All units equal. When numbering and labeling, you must use the same movement between each line (for example: 2, 4, 6, 8) Always label the line on the y (vertical) axis. The y axis is reserved for the responding or dependent variable. The x axis or horizontal axis can be labeled between the lines. The x axis is reserved for the manipulated or independent variable. Your graph must have a title. The graph title gives an overview of the information being presented in the graph. The title is given at the top of the graph.
The speed of the car determines the cost of the speeding ticket, so the cost depends on the speed. Cost is the dependent variable and goes on the Y axis (vertical axis). Speed is the independent variable and goes on the X axis (horizontal axis). **** Graphs are used to observe general trends in data
Biochemistry:
Organic Molecules: Contain both Carbon and Hydrogen bonded together and is associated with living things.
Examples: Carbohydrates: starches (large molecule) made up of sugars (small molecule) All sugars end in “ose” All carbohydrates contain carbon, hydrogen & oxygen Proteins: made up of amino acids (there are 20 different amino acids) Function: growth & repair, energy, buffer (helps keep body pH constant) Components of cell structures & organelles. Examples: insulin, hemoglobin, enzymes(speed up chemical chemical reactions) All proteins have an amine group(NH2), carboxyl group(COOH), and an R group Lipids(fats, oils, waxes): made up of fatty acids and glycerol Function: energy storage, protection & insulation Key component in cell membrane Inorganic Molecules: Don’t contain both carbon & hydrogen Examples: Carbon Dioxide (CO2), Hydrogen peroxide (H2O2), Salt (NaCl), water ( H2O) Major Types of Reactions in Living Things •
1. Dehydration Synthesis: Chemical combination of two small molecules to make one larger molecule caused by the removal of water. Dehydration – removing water + Synthesis – combining of two smaller things to make 1 larger thing
•
2. Hydrolysis: (digestion) – Addition of water to a larger molecule to form 2 or more smaller molecules Opposite of dehydration synthesis –
hydro(water) + lysis (break apart) = break apart with water
Enzymes: The controller of all CHEMICAL reactions in your body
Chemical Control (Enzymes) -at all times there are billions of chemical reactions taking place in any organism -all organisms therefore need to control these chemical reactions that make up metabolism. -enzymes are the principal regulators of most chemical activity in living systems - Enzymes control chemical reactions and therefore control Metabolism **** There are over 2000 known enzymes, each of which is involved with one specific chemical reaction Enzymes - enzymes are proteins - enzymes are referred to as organic catalysts catalysts - inorganic or organic substance which speeds up the rate of a chemical reaction. – Chemical reactions like Dehydration Synthesis and Hydrolysis • activation energy - the energy that must be overcome in order for a chemical reaction to occur. – Activation energy may otherwise be denoted as the minimum energy necessary for a specific chemical reaction to occur. • - enzymes lower the energy needed to start a chemical reaction (lower activation energy) Structure • Structures of Enzymes - enzymes are large, complex proteins Protein - all enzymes are either all protein or are protein with non-protein parts called coenzymes - coenzymes are often vitamins ASE • Enzymes are named according to the substrate they are specific to - substrates are the chemicals that each enzyme acts upon Examples of Naming: • The enzyme maltase (enzyme) breaks down (acts upon) the dissaccharide maltose (substrate) into 2 monosacchardies • The enzyme peptidase breaks the peptide bonds in proteins • - Usually enzymes end in – ase • •
Lock and Key Theory” • "Lock and Key Theory" -- each enzyme is specific for one and only one substrate(one lock - one key) • It is thought that, in order for an enzyme to affect the rate of a reaction, the following events must take place. • Enzyme Substrate Complex 1. Enzyme forms a temporary association with the substrate or substrates 2. The Enzyme and Substrate form a close physical association between the molecules called an enzyme substrate complex. 3. While the enzyme substrate complex is formed, the enzyme action takes place and the substrate is broken down into its smaller, simpler parts (Example: a disaccharide becomes 2 monosaccharide or 2 monosacchardies become a disaccharide) • 4. After completion, the enzyme and the products separate. The enzyme is then ready to react with another substrate.
Note: Enzymes do eventually wear out, so they have to be synthesized by the cells and replaced. **** - Enzymes are not changed during reactions and therefore can be reused Factors that influence Enzyme activity: The function of specific enzymes is most directly influenced by its shape. Increased temperature and pH can alter (change) the specific shape of an enzyme. As temperature increases above the optimum temperature (Temp. at which enzyme functions most efficiently), rate of enzyme action begins to decrease. Each enzyme has a particular pH at which it functions more efficiently. Enzymes, antibodies and hormones are similar because their chemical structure is critical to their ability to function. Active Site or Binding Site -enzymes are usually much bigger than their substrates -the protein chains fold to make a three dimensional shape that has a specific pocket or site where the substrate can fit and interact. -the specificity of the enzyme is dependent upon its active site Many biological catalysts (enzymes), hormones and receptor molecules are similar in that in order to function properly, they must contain amino acid chains that fold into a specific shape.
Cells: contain a variety of small structures called organelles which perform special functions Organelles cells tissues organs organ systems organism Unicellular organisms (single cell) carries out life functions without using organ systems. Organelles carry out life processes similar to the organs and tissues in multicellular organisms. Life on Earth began as single celled organisms. The cell membrane acts like kidneys and lungs absorbing oxygen & water and getting rid of wastes (CO2, salts, nitrogenous wastes). It also absorbs nutrients. Multicellular organisms has organ systems that interact to carry out life functions. Homeostasis : maintenance of internal stability. To maintain homeostasis, cells must respond & adapt to both their internal & external environment. Homeostasis is maintained by the interaction of organelles. If homeostasis fails: disease/get sick because body can’t carry out life processes (respiration, digestion, excretion…) Example of homeostasis: after breakdown of glucose to release energy, the removal of waste products must occur. Cell organelles
Nucleus: contains chromosomes (DNA), directions for protein synthesis ( in ribosomes) comes from here. Coordinates all processes that takes place in the cell Mitochondria: cellular respiration ( energy-ATP made) occurs here, “powerhouse of cell”-Energy Cell membrane(plasma membrane): carries out function similar to human excretory system, only allows certain things to pass through it (selectively permeable). It is made up of a double lipid layer in which protein molecules float.
Cytoplasm: carries out function similar to circulatory system Ribosomes: Due to interaction of digestive and circulatory systems proteins digested amino acids circulatory systemdiffuse across cell membrane ribosomes protein synthesis Chloroplasts: found only in plant cell, photosynthesis occurs here, contains chlorophyll (green pigment) which traps sunlight for photosynthesis.
Transport: Diffusion, Osmosis and Concentration Gradient Diffusion – the movement of a substance from a high concentration to a low concentration. Osmosis – the movement of water from a high concentration to a low concentration. Concentration Gradient – the difference in concentration between a region of high concentration and a region of low concentration. Passive & Active Transport: Passive Transport – does not require cell energy. Examples: Diffusion, Facilitated diffusion and Osmosis Active Transport – requires cell energy (ATP). Examples: Carrier mediated active transport, Endocytosis and Exocytosis Methods of Transport: 1. Diffusion: the random movement of particles of a solute from an area of high concentration to an area of low concentration. Certain things are allowed to pass, based on size. Particles always move with (down) a concentration gradient (the difference in concentrations across a membrane) EX: Passive transport Equilibrium Diffusion stops at equilibrium (when the concentrations across a membrane are equal). The movement of molecules continues at equilibrium but the # of molecules moving across the membrane remains the same. The rate of transport is dependent on: 1) if the material is solid, liquid or gas. 2) the size of the molecules. 3) temperature Examples of molecules that can diffuse through the bilayer: carbon dioxide, oxygen, water but very, very slowly. Diffusion through a Plasma Membrane
Osmosis Osmosis: the diffusion of water through a selectively permeable membrane. Passive transport Water molecules move from a higher concentration of water to a lower concentration of water. Water will move to where there is a greater amount of solute because there is less water there Isotonic Solution Isotonic solutions: the concentration of solute inside and outside the cell is the same. Isotonic: Water in = Water out No net movement of water. Molecules in equilibrium. Normal state for animal cells. Cell in homeostasis.
Hypotonic Solution Hypotonic solutions: the concentration of solute is lower outside the cell than inside the cell. Have more water outside the cell so water moves into the cell. Causes an increase in pressure inside the cell: called turgor pressure (plants) or osmotic pressure (animals). Increase in pressure in animal cells causes them to swell or even burst; gives plant cells shape and support. Hypotonic: Water enters cell. Cell swells and bursts (cytolysis). Give plant cells shape and support.
Hypertonic Solution Hypertonic solutions: the concentration of solute is higher outside the cell than inside the cell. Have more water inside the cell so water moves out of cell. Causes a drop in turgor or osmotic pressure: called plasmolysis. Plasmolysis causes animal cells shrivel up and plant cells to wilt. Hypertonic: Water exits cell. Cell shrinks (plasmolysis) due to water loss.
Facilitated Diffusion Particles always move with (down) a concentration gradient. Uses transport/channel proteins. Passive transport. Usually for specific molecules such as glucose. Facilitated diffusion stops at equilibrium Active transport Active Transport: requires energy in the form of ATP. Capable of moving solute particles against the concentration gradient (from low concentration to high concentration) Uses transport/carrier proteins ( protein pumps) embedded in the plasma membrane . Carrier proteins are specific for the molecules that they allow through. The carrier protein changes shape which requires energy (ATP).
Cellular Respiration Cellular respiration : is the process by which organisms can get energy(ATP)from their food (glucose) Cellular respiration is critical for life. It occurs in both plants and animals. Main Types of Cellular Respiration Pathways Anaerobic Respiration Evolved first Don’t require oxygen Start with glycolysis in cytoplasm Completed in cytoplasm Aerobic Respiration Evolved later Require oxygen Start with glycolysis in cytoplasm Completed in mitochondria Aerobic Respiration
C H 0 + 6O 6 12 6
2
glucose oxygen
2
2
carbon water energy
dioxide
*** This equation is the reverse of photosynthesis***
6CO + 6H 0 + ATP
Cellular Respiration compared to Photosynthesis Cellular Respirtation Photosynthesis Function Energy release Energy capture Location Mitochondria Chloroplast Reactants C6 H12 O6 & O2 CO2 & H2O Products CO2 & H2O C6 H12 O6 & O2 6O2 + C6 H12 O6 6CO2 + 6H2O Formula 6CO2 + 6H2O C6 H12 O6 + 6O2 Anaerobic Fermentation Fermentation Sometimes a cell can‘t get the oxygen it needs to carry out cellular respiration. It carries out fermentation instead to get the energy (ATP) that it needs. It is less effective, and doesn’t make as much ATP. Location: Cytoplasm Isn’t a “clean burn”, so nasty or intoxicating, waste products are left behind. There are 2 types: Alcoholic Fermentation Produces ethanol (alcohol) as a waste product. Used for producing beer, wine and rising bread. Lactic Acid Fermentation Produces lactic acid as a waste product. Is part of the burn you feel when you exercise.Muscle fatigue occurs when lactic acid builds up in muscle cells. To end muscle fatigue, muscles need to get oxygen. Photosynthesis: is the process in which the sun’s energy is captured to make sugars that store chemical energy. Sugar is a carbohydrate molecule. It is a link between abiotic factors (sunlight, H2O, CO2) & energy needs(glucose for respiration) of an entire ecosystem. Energy from the sun is converted into chemical energy in the bonds of an organic molecules.
Chlorophyll is a green pigment in chloroplasts that absorbs light energy to start photosynthesis. • •
Plants only use water (H O) and carbon dioxide (CO ) and light energy to create sugars (C H O ) = 2
2
6 12
6
chemical energy. (Autotroph) Heterotrophs then consume this sugar and break it apart to get the chemical energy (ATP from mitochondria) to carry out their life processes • • Photosynthesis Equation • • • • • •
enzymes 6CO + 12 H O + hv C H O +6O +6H O 2
2
Carbon Water Dioxide
6
sunlight
12
6
2
2
Glucose Oxygen Water (sugar)
hv = sunlight ** You should memorize this equation! You will see it again!
• • • • • • •
Function of photosynthesis: Produces food for all organisms Provides material for plant growth /development Sugars used for energy by the mitochondria Simple sugars become starch & cellulose (in cell walls) “carbohydrates” Helps regulates Earth’s environment Removes CO2 from atmosphere and adds O2
Factors that affect photosynthesis “Biological Process” Light intensity-‐ As intensity increases, photosynthesis increases until all pigments are being used, then photosynthesis levels off. CO2 concentration-‐ As the concentration increases, photosynthesis increases to a point Temperature-‐ As temp. increases, photosynthesis increases to a point, then a decrease will occur if temp. continues to increase 2 stages of photosynthesis:
Genetics Intro DNA The Cell •
Smallest unit of life
•
Compose all living things
•
The “nucleus” – (one of the many organelles), contains genetic information that the cell needs to exist and reproduce. Contains the code for production of proteins(enzymes, hormones)
-‐ Chromosomes: most cells organize genetic information into Chromosomes our body’s way of organizing all the information that our genetic material contains. •
23 pairs of chromosomes in humans -‐ each pair contains one from mother and one from father
Genes •
Each chromosome contains 100s to 1000s of information blocks called genes
•
Each gene is the blueprint for a specific protein in the body
-‐
may tell our body what color our eyes are supposed to be, dozens of proteins are responsible for synthesis of ATP , digesting food, etc, etc etc
Genes are inherited, but their expression can be modified by their environment.
Example: Some animals have dark fur only when the temperature is in a certain range (temp. can affect the expression of some genes)
•
Each chromosome and every gene is made of deoxyribonucleic acid (DNA)
•
DNA is a polymer of repeating units called nucleotides
•
Each nucleotide contains three parts
-‐ Phosphate
-‐ Nitrogenous base
deoxyribose (sugar)
The DNA Double Helix •
DNA is normally double stranded
•
The two nucleotide chains are held together by hydrogen bonds
•
A always pairs with T on the other strand; C always pairs with G
Functions of DNA •
Two primary functions -‐ transmit information from one generation to the next -‐ provide blueprint for making proteins the same way every time
DNA Replication •
DNA is unwound.
•
An enzyme called DNA Polymerase adds complementary bases to “single stranded”
-‐ A with T
-‐ C with G
Changing one base in a gene could have a direct effect on the sequence of building blocks of a protein found in a cell. Restriction Enzymes Enzymes or biological catalysts cuts DNA at specific sequences Recognize and binds to 6-‐8 nucleotide stretch Gel Electrophoresis: separates (arranges) DNA in the lab. This method helps to determine: If 2 organisms are closely related, Help identify criminals at crime scenes, Help to identify victim of crime, for paternity cases ( I.d. the father of a child)
With Gel Electrophersis, 2 organisms are related if: Base sequences of DNA are the same (same DNA) The # of bands would be the same The bands would be at the same position (same banding pattern) Chromatography of pigment extracts can be used for plants to see if plants are genetically related. Every cell in a human body has the same DNA and yet cells perform different functions (jobs). Examples: nerve cells, & muscle cells This occurs because different parts of genetic instructions are used in each type of cell. Mendelian Genetics Genetics is the scientific study of heredity. Heredity is what makes each species unique. Gregor Mendel Known as the “Father of Genetics”: His experiments with pea plants from 1856-‐1863 began our understanding of how traits, things like hair or eye color, height, weight, ect……., were passed down from generation to generation. He came up with the principles of heredity that still hold true today His work started and formed the base of all genetics , a field we learn more about every day. The Principle of Dominance The principle of dominance states that some alleles are dominant and some are recessive. Dominant alleles are always expressed. Represent by a capital letter(B – Dominant for Brown eyes) Recessive alleles are only expressed if both alleles are recessive. Got a recessive gene from both mom & dad. Represented by a lower case letter (b – recessive for blue eyes)
Genetics vocabulary: organism with 2 identical alleles for a trait are homozygous. ( TT or tt) Big letters= Dominant small or lower case = recessive. Organisms with 2 different alleles for a character are heterozygous ( Tt or Pp) The physical expression of genes is known as phenotype Ex) What it looks like, tall, short, white, black ect…. The actual genetic makeup is known as the genotype. Ex) Homo. D or R, Hetero. D or R.
Intermediate Inheritance some alleles show intermediate inheritance where heterozygotes show a distinct intermediate phenotype, not seen in homozygotes. When 2 dominant genes come together and neither is fully expressed. This results in a new mixed phenotype. Snapdragons come in Homozygous Dominant Red and Homozygous dominant white. When these two plants are crossed the flowers are heterozygous pink. A mix between red and white This is also called incomplete dominance.
Codominant codominance 2 alleles affect the phenotype in separate, distinguishable ways 2 dominant alleles expressed at the same time. When both alleles are dominant for a different trait and both are expressed separately. (NOT MIXED) Flowers can often be co-‐dominant. When you see a flower with 2 different color petals it is an example of co-‐ dominance. Both colors are expressed and not mixed. Other examples include snakes and chickens Ex. Is blood type. This is also a multiple allele gene have 3 alleles present (A,B, O ) A & B alleles are codominant O alleles are recessive. Fact: Just because an allele is dominant does not make it more prevalent in a population. Ex. Polydactyl is dominant to having the normal 5 fingers and toes but 399 out of 400 have the recessive what we call normal 5 and 5
Blood type A and Blood type B are Co-‐dominant, so you get type AB blood
Co-‐dominant chicken feather color
Linked Genes The tendency of some genes to be inherited together is known as linked genes. Ex – red hair and freckles Ex – Red hair and fair skin Sex Linked Genes If a gene is found only on the X chromosome and not the Y chromosome, it is said to be a sex-‐linked trait Baldness is a recessive sex linked trait. Found on the X chromosome. Females usually don’t go bald because they have two copies of the gene and usually 1 works properly. XX But males only have one X chromosome. (XY) There is no matching gene on the y chromosome .So if mom gives the X chromosome with the recessive allele then her son will go bald.
Sex Linked Disorders Muscular Dystrophy Monogenetic, sex linked recessive Muscular dystrophy is a disease in which the muscles of the body get weaker and weaker and slowly stop working because of a lack of a certain protein. Most types of MD are multi-system disorders with manifestations in body systems including the heart, gastrointestinal and nervous systems, endocrine glands, skin, eyes and other organs Hemophilia Hemophilia is the oldest known hereditary bleeding disorder. Monogenetic, sex linked recessive There are about 20,000 hemophilia patients in the United States. The severity of hemophilia is related to the amount of the clotting factor in the blood. About 70% of hemophilia patients have less than one percent of the normal amount and, thus, have severe hemophilia. Color Blindness Monogentic, Sex-linked recessive 1/10 males have, 1/100 females have. Unable to distinguish shades of red & green, sex-‐linked recessive
Mutations Mutation –is a change in the sequence of bases in DNA. If a gene that encodes for a specific protein is mutated, it may result in a change in the sequence of amino acids comprising the protein. The activity of the protein may be altered. - A change from one hereditary state to another - Due to an alteration in the DNA of an organism.
How Do Mutations Occur? As UV radiation increases, mutations will increase • Everyone acquires some changes to their DNA during the course of their lives. • These changes occur in a number of ways. – Sometimes there are simple copying errors that are introduced when DNA replicates itself. – Other changes are introduced as a result of DNA damage through environmental agents. • Our cells have built in mechanisms that catch and repair most of the changes that occur during DNA replication or from environmental damage. Errors can occur in the DNA of cells that produce the eggs and sperm. These mutations and can be passed (inherited) from parent to child. If a child inherits this mutation from their parents, every cell in their body will have this error in their DNA.
•
Mutations that occur in body cells (not gametes-sperm & egg), will be only passed on to other body cells that form from mitosis of the mutated cell. These are not passed onto offspring because the mutation is not in the sperm or egg (gametes) Example: mutation in skin cell, the altered genes will be passed on to every cell that develops from that skin cell. Classes of Mutations • Mutations result from two underlying causes • 1. substitutions –One base in the DNA is substituted for another base. Incorrect base pairing results from the change of a single nucleotide base. • 2. insertions or deletions of one or more bases- may result in the addition or deletion of one or more amino acids to the growing protein. Genetic Disorders
Genetic disorders are medical conditions caused by mutations in a gene or set of genes Other disorders are caused by changes in the overall structure or number of chromosomes Monogenetic Disorder – Disorder controlled by one gene Chromosomal Disorder – Extra or missing chromosome
Chromosome Disorder Down’s Syndrome Caused by nondisjunction of the 21 st chromosome. This means that the individual has a trisomy (3 – 2lst chromosomes). 1 in 800 babies born with D. syndrome Causes various physical & mental disabilities.
Karotype of Down’s syndrome Chromosomes are arranged to show homologous pairs. A person with Down’s syndrome has an extra # 21 chromosome ( 3-trisomy of #21 instead of 2), due to nondisjunction(failure of homologous chromosomes to separate during meiosis). This karyptype is a female because there are 2 X (XX) chromosomes. A male would have XY chromosomes. Chromosomes # 1-22 are autosomes and chromosomes # 23 are the sex chromosomes (XX or XY) People have changes in speech patterns and mental retardation. Down’s syndrome can be identified before a child is even born, by doing a Karyotype on the amniotic fluid surrounding the fetus. This is called amniocentesis, and is used to detect many genetic disorders.
Monogenetic Disorders Sickle Cell Anemia People receive a code for the production of abnormal hemoglobin (found in red blood cells). Sickle cell disease is most commonly found in African American populations. The clumps of sickle cells block blood flow in the blood vessels that lead to the limbs and organs. Blocked blood vessels can cause pain, serious infections, and organ damage. 1 in 12 African Americans have sickle cell trait.
An inherited, chronic disease in which the red blood cells, normally disc -shaped become crescent shaped.
Phenylketonuria or PKU - - People with PKU cannot consume any product that contains aspartame. - Characterized by a deficiency in the enzyme phenylalanine hydroxylase (PAH). - This enzyme is necessary to metabolize the amino acid phenylalanine to the amino acid tyrosine PKU Phenylalanine is an essential amino acid and is found in nearly all foods which contain protein, dairy products, nuts, beans, tofu… etc. A low protein diet must be followed to control the disorder. Brain damage can result if the diet is not followed causing mental retardation…and mousy body odor (phenylacetic acid is in sweat). All new born babies have a PKU blood test to determine if they have PKU. The disorder must be identified shorty after birth so the baby can be put on the correct diet to prevent brain damage.
Tay-Sachs Disease Characterized by a buildup of fatty tissue in the nervous system Monogenic, autosomal recessive Central nervous system degrades, ultimately causing death. Most common among people of Jewish, eastern Europe descent. Cloning Cloning- the process of making an identical organism through non sexual means (asexual reproduction). An exact copy of the original organism will be produced. Human cloning experiments has not occurred because many people think this is unethical. Are there different types of cloning? The following three types of cloning technologies will be discussed: (1) recombinant DNA technology or DNA cloning (2) reproductive cloning (3) therapeutic cloning Recombinant DNA Technology or DNA Cloning The DNA of interest can then be propagated in a foreign host cell. This technology has been around since the 1970s, and it has become a common practice in molecular biology labs today. Recombinant DNA used in biotechnology industry to synthesize (make) insulin, interferon & human growth hormone(HGH) “Genetic Engineering”
Reproductive Cloning Reproductive cloning is a technology used to generate an animal that has the same nuclear DNA as another currently or previously existing animal. Scientists transfer genetic material from the nucleus of the donor adult cell to an egg whose nucleus , and thus its genetic material , has been removed.
The reconstructed egg containing the DNA from a donor cell must be treated with chemicals or electric current in order to stimulate cell division. Once the cloned embryo reaches a suitable stage, it is transferred to the uterus of a female host where it continues to develop until birth.
Thousands of people die every year waiting for a transplant Cloning technology could someday be used to produce whole organs. Embryonic stem cells also have the potential for use in the production of tissues. They can also be used to grow neurons to cure those who suffer from Alzheimer's, Parkinson's.
What are the risks of cloning? In addition to low success rates, cloned animals tend to have more compromised immune function and higher rates of infection, tumor growth and other disorders. Many cloned animals have not lived long enough to generate good data about how clones age. Clones have been known to die mysteriously. For example, Australia's first cloned sheep”Dolly” appeared healthy and energetic on the day she died, and the results from her autopsy failed to determine a cause of death. Selective Breeding Selective Breeding (artificial selection): common practice among breeders to maintain a desired trait. Parents are chosen who have desirable traits .Hopefully the off spring will have these traits. This is used to produce new varieties of domestic animals. Disadvantages of selective breeding: Some undersirable traits of parents may be expressed (show up) in offspring Unexpected combination of genes Unpredictable results Decreased variation in organisms Genetic Engineering: removal of DNA from one organism & insert it into another organism to produce a new substance. Products must be tested to make sure they are safe. Examples: Insulin production Human growth hormone Insert a gene into a plant species to increase fruit production. Insert human gene for anti- blood clotting factor into egg cells of goats. Goats born from fertilized eggs produce the anti- clotting factor in their milk.
Gene manipulation : Example: inserting a section of DNA into a poisonous plant to make it non-poisonous Each organ uses different genes to make different enzymes. Some bacteria may have a natural resistance to a drug or chemical ( antibiotics) due to a mutation. If used too many times some antibiotics become less effective against certain bacteria (pathogens). The bacteria will survive, & reproduce causing the person to remain sick. This causes doctors and scientists to find new antibiotics to kill the bacteria. Variation in offspring is the direct result of sorting and recombination of genes (sexual reproduction). Coded instructions passed from one generation to the next can be most directly changed by the processes of recombination, mutation & genetic engineering. Genetically altered viruses can be used to treat diseases, cure diseases & control diseases. Cancer: mutation of cells, they reproduce (mitosis) uncontrollably (mutates) & forms a tumor.
radiation Normal cell or other mutation causing agent
mutation
risk of cancer increases
Asexual Reproduction produces offspring identical to parent
Example: Vegetative propagation-‐ roots develop from stem cutting
Budding-‐ small bud (daughter cell) forms off of parent
Sexual Reproduction produces offspring not identical to the parents. There is a genetic variation since the parents genes are mixing. Each parent has 2 genes for each trait ( one from their mom & one from their dad). During Meiosis gametes(sperm & eggs) form, each gamete receives half the total number of chromosomes . Human: Has 46 chromosomes in each body cell. There are 22 pairs of autosomal chromosomes and one pair of sex chromosomes Each sperm and egg have 23 chromosomes. There are 22 autosomal chromosomes and one sex chromosome. Sperm (22 auto, 1 sex chrom.) + egg (22 auto & 1 sex chrom) = fertilized egg (zygote) with 46 chromosomes XX is a girl XY is a boy
Egg
Sperm
Zygote (fertilized egg)
Pedigree chart
Males only have one X chromosome (XY), so if the only X they have (from mom) has the gene for color blindness, they will be color blind. Females need both X’s to have the gene for color blindness to be color blind. If females have one X with the gene for color blindness (heterozygous) they have normal color vision, but could pass the gene on to their children . If mom is color blind(Xc Xc)and dad has normal color vision (XC Y), all sons will be color blind (XcY) and daughters will be carriers( XC Xc) Environment can affect genes: Identical twins separated at birth can have different height, weight & IQ because home life affected these characteristics.
Evolution Evolution: change over time Gradualism slow and continuous rate of evolution Modern Theory: “Natural Selection” organisms best adapt to a changing environment are more likely to survive, reproduce, & pass their genes on to offspring. “Survival of the fittest”. Variations that influence the evolution of sexually reproducing species are due to the process of mutation & genetic recombination. Organisms with a wide variety of traits will have a greater chance of survival if the environment changes suddenly. Changes that occur in the sex cells (sperm & egg) can be the basis for evolutionary change. As the environment or food source changes, there will be a completion for survival among species. Extinction: if organisms don’t have the traits to survive, they will die out Adaptations help organisms to survive. Evidence of evolution: Support the concept of organic evolution ( similarities in these indicate a common ancestor)
Comparative biochemistry: organisms have similar DNA (base sequences), protein, hormones, insulin. Then they share a common ancestor. Comparative embryology: If embryos (unborn) look similar in the early stages of development, then they share a common ancestor. Comparative anatomy: study of bones & organs “structural”, if similar between organisms they share a common ancestor. Comparative cytology: study of organisms cells looking for similarities to determine common ancestry Fossils: Evidence of how certain organisms have changed (evolved ) through time ( they look similar to each other) . Oldest least complex (simple) fossils are on the bottom and youngest and most complex is on the top.
Fossils are found in layers of sedimentary rocks. The oldest fossil is on bottom, youngest on top. Fossil E is the oldest & fossil A is the youngest
Most of the species that lived on Earth, no longer exist (extinct). Fossil record of ancient life forms provide evidence of evolutionary changes.
Theories of Evolution Jean Baptiste Lamarck: Use & Disuse Theory
New organs arise due to an organisms need for the organ. Example: Short neck giraffes stretched their necks reaching for food, necks became longer & long neck trait was passed on to their offspring. Charles Darwin: Natural Selection Theory Organisms best adapted (favorable variations) to the changing environment will survive and reproduce. These favorable traits will be passed onto their offspring. Genetic variations are differences produced by sexual reproduction or mutations. “Survival of the fittest” If the climate/environment changes, organisms who can’t adapt to the new environment will die. ** One problem with Darwin’s theory of evolution was he couldn’t explain how genetic variations occurred.**** What made Darwin come up with his theory of evolution? Darwin studied the finches in the Galapagos Islands and saw different adaptations to their beaks depending on what they ate (environment).
If the finches’ food source was no longer available, they could die because their beaks are not the right shape for a new food source. Some with different shaped beaks survived by eating the new food source and reproduced passing on the gene for the beak shape to their offspring. They all have the same common ancestor.
Branching Tree “polygenetic tree”
All have a common ancestor ( grandparent). You & sibling are more closely related to each other because they are 2 twigs off the same branch (closer to each other on tree) and have a specific common ancestor (parent). Geographic Isolation: animals from the same species cannot mate (reproduce) because they are physically separated by mountains, rivers & large bodies of water. Mutation occurring today Some bacteria have a mutation that makes them resistant to antibiotics. This means that these drugs can’t kill the bacteria. These bacteria will survive and reproduce passing the resistance to antibiotics on to their offspring. Before you know it the number of bacteria resistant to antibiotics will increase causing people to become very sick and some may die. Solution: Scientists need to develop new antibiotics to kill the resistant bacteria
The body systems Digestive system: 3 Stages of Digestion 1. Digestion -‐ breakdown of food into particles/molecules small enough to pass into the blood stream. 2 types of digestion mechanical (Mastication): chewing food into smaller pieces chemical (Enzymes), starch digestion begins here 2. Absorption of nutrients into the blood stream 3. Elimination of indigestible nutrients
The Mouth
Mechanical breakdown of nutrients begins in the mouth by chewing (Mastication). The purpose of chewing is to increase the surface area of food. Chemical breakdown of starch also begins in mouth. Starch is converted into glucose by salivary amylase (secreted by the salivary glands).Starch cannot enter into a cell because it is too large, it must be broken down into sugar. Epiglottisprevents you from choking by closing and not allowing food to go into the trachea. The esophagus is a muscular tube whose muscular contractions (peristalsis) propel food to the stomach. Peristalsis also occurs in stomach, small & large intestine. Peristalsis – the wave action of muscle that moves food through the digestive system.
The stomach Gastric juice contains hydrochloric acid(HCl), pepsinogen, and mucus Stomach HCl: activates pepsinogen (to pepsin) Pepsin is an enzyme that starts protein digestion.
Epithelial cells secrete mucus that forms a protective barrier between the cells lining the inside of the stomach and the stomach acids. The stomach also mechanically churns the food. Chyme, (liquefied food) the mix of acid and food in the stomach, leaves the stomach and enters the small intestine.
The Small Intestine The small intestine is the major site for digestion and absorption of nutrients. 98% of digestion and 100% of absorption of nutrients occurs in the small intestines. Small intestine is made up of 3 parts: Duodenum, Jejunum, Ileum Chyme (liquefied food) is pushed out of the stomach into the small intestines. The acid chyme stimulates the Liver and the Pancreas. The pancreas secretes digestive enzymes and stomach acid-‐neutralizing sodium bicarbonate.(2 pH 8 pH) into the small intestine. Enzymes -‐ Lipase, Amylase, protease The liver produces bile, which is stored in the gall bladder before entering the bile duct into the small intestine Bile emulsifies fats (breaks fats into little pieces)
The small intestine is lined with villi and microvilli The purpose of villi and microvilli are to increase surface area in the small intestines. Increase the speed at which nutrients are absorbed
A: Esophagus B: Stomach
C: Pancreas
D: Small intestine
E: Gallbladder F:Liver
The Liver and Gall Bladder The Liver makes Bile and stores it in the gall bladder. The Gall bladder sends bile to the small intestine when the acidic chyme from the stomach. Bile contains bile salts, which emulsify fats, making them susceptible to enzymatic breakdown. The liver also stores excess glucose in the form of glycogen.
Carbohydrate Digestion step by step
Carbohydrate digestion begins in the mouth The chime(liquefied food) is pushed into your small intestines (duodenum) which triggers the release of Pancreatic juice from the pancreas The enzymes break down large carbohydrates into smaller molecules Finally the intestinal glands release intestinal juice which includes the enzymes The smaller carbohydrate is broken down into even smaller molecules(glucose) which are absorbed by the blood stream. Glucose can diffuse into the blood without first being digested.
Protein Digestion Step by Step
Proteins begin to be digested in the stomach . The chyme is pushed into your small intestines (duodenum) which triggers the release of Pancreatic juice from the pancreas One of the enzymes(protease) in pancreatic juice continues the breakdown of proteins into Peptide bonds Finally the intestinal glands release intestinal juice which breaks peptide bonds into amino acids. Those amino acids are absorbed into the blood steam and carried to the cells . Amino acids are broken down in the liver to produce wastes that contain nitrogen.
Digestion of Lipids
The chime (liquefied food) is pushed into your small intestines (duodenum) which triggers the release of Pancreatic juice from the pancreas and bile from your gall bladder. Bile emulsifies (chews) the lipids to increase surface area Pancreatic juice hydrolyses lipids into a glycerol and 3 fatty acids The products are absorbed by the small intestines and carried to the cells for use. The Large Intestine
Digested food is pushed from the small intestines into the large intestine. No digestion takes place in the large intestines Material in the large intestine is mostly indigestible residue and liquid. Water, and salts are absorbed, the remaining contents form feces (mostly cellulose, bacteria, bilirubin). Bacteria in the large intestine, such as E. coli, produce vitamins (including vitamin K) that are absorbed.
Ulcers
Peptic ulcers result when the protective mucus fails and the HCl eats away at the lining of the stomach. Bleeding ulcers result when tissue damage is so severe that bleeding occurs into the stomach. Perforated ulcers are life-‐threatening situations where a hole has formed in the stomach wall. At least 90% of all peptic ulcers are caused by Helicobacter pylori (bacteria). Other factors, including stress and ibuprofen, can also produce ulcers.
Digestion of a Sandwich: sandwich mouth mechanical & chemical digestion starch glucose (Bread) chewing:smaller pieces enzyme:amylase simple sugar:small molecule Starch is a large molecule, it must be broken down (digested) into a sugar(small molecule), so it can cross the cell membrane of cellsmitochondriacellular respirationATP formed(provides energy to cells) Large molecule
digestion Smaller molecule
Proteins
amino acids
Starch
sugar (glucose)
Fats
fatty acids & glycerol
Excretory System: removes toxic wastes, dissolved molecules, & gaseous waste, maintaining dynamic equilibrium in the body Organs of Excretory System Lungs – CO2 and water Skin – Sweat (temperature regulation) Kidneys – Urine Liver – detoxification of blood: breaks down red blood cells and synthesize urea( breakdown of amino acids) These organs work with other body systems to keep the body in homeostasis. Excretion – is the process by which waste and excess substances are removed from the body. If wastes from metabolism (metabolic wastes) are not removed from the body, the body will die. Metabolic wastes come from chemical reactions in the cells of the human body The Skin
The skin performs a number of different functions one of them is excretion of wastes and removal of excess heat. In sweat there is a small amount of urea and salts. Sweat 99% water 1% Urea and Salts( sweating helps regulate body temperature) Lungs Excrete CO2 and Water The end products of cellular respiration Urinary System
Waste is filtered from the blood and collected as urine in each kidney ( main organ of excretion). Urine leaves the kidneys by ureters, and collects in the bladder. The bladder can distend to store urine that eventually leaves through the urethra The urinary system: Kidneys : filters blood & produces urine Ureters: transports urine to bladder Bladder: stores urine urethra: pathway for urine to exit the body
Sequence of correct path to remove urine from the body: Kidney ureterurinary bladder urethra Kidneys (nephron: structural unit): regulates chemical composition of the blood The Nephron: A is the glomerulus & B is the bowman’s capsule
There is a large number of mitochondria in the nephrons indicating that the transport of materials into and out of the nephron requires a lot of energy (active transport) Bean shaped organs that are about 10cm long Main Functions: Remove wastes of cellular metabolism (metabolic waste) Regulate the concentrations of the substances in the blood On a hot day , if someone is sweating too much the kidneys will decrease urine production allowing the body to conserve water. Urine: water + urea = salts Disruption of Kidney Function Infection, environmental toxins such as mercury, and genetic disease can have devastating results by causing disruption of kidney function. Many kidney problems can be treated by dialysis, where a machine acts as a kidney. Kidney transplants are an alternative to dialysis. Gout is a condition in which excess production and deposition of uric acid occurs
The Respiratory System: Conducting passageways carrying air to and from the alveoli Respiratory passageways permit exchange between the external atmosphere & circulatory system. Upper respiratory passages filter and humidify incoming air (cilia & mucous membranes) Lower passageways include delicate conduction passages and alveolar exchange surfaces
Respiratory Mucosa • •
This mucus protects delicate lower respiratory track by filtering out dust, dirt, and pathogens This mucus is then removed from the body or sent to the stomach for the stomach acid to destroy pathogens
The Respiratory System has two Major Responsibilities • • • •
Supply the blood (and ultimately the tissues) with O2. Remove CO2 Simply stated: Respiration involving breathing O2 in and expelling CO2. However, it’s more complicated than that.
The Two types of respiration • •
Internal Respiration: within the cells, cellular respiration External Respiration: involves movement of air and gasses
Internal Respiration Internal respiration refers to the metabolic processes occurring using sugar and oxygen making energy in the mitochondria. • Molecular oxygen is used by tissue cells. • Carbon dioxide is produced 2 Types of Internal Respiration •
“cellular respiration” uses oxygen & sugar to produce energy •
Aerobic respiration – With Oxygen C6H12O6 + 6O2 6CO2 + 6 H2O + 36 or 38 ATP
•
Anaerobic respiration – Without Oxygen C6H12O6 2CO2 + 2C2H5OH + 2 ATP External Respiration • •
The sequence of events involved in the exchange of O2 and CO2 between the external environment and body’s cells. It includes: Breathing: air moved between the atmosphere and Lungs (alveoli). Gasses exchanged between the lungs and the blood. Movement of gasses between the lungs and the tissues.
Airways conduct air between the atmosphere and alveoli •
Inhaled air passes through the following series of continuous airways in this sequence: Nasal passages: lined with mucus membranes that filter, moisten & warm air Pharynx Larynx Trachea: lined with ciliated mucus membrane (filter & moisten air), supported by cartilaginous rings (causes trachea to remain open) Bronchi (left and right) Bronchioles :small branching tubes, lack cartilage rings Alveoli : gas exchange occurs here (CO2 leaves blood goes into lungs and is exhaled & O2 enters blood). Surrounded by capillaries. Air pathway: nasal passagepharynxlarynxtracheabronchibronchiolesalveoli
Epiglottis prevents food from entering trachea
Alveoli
• • •
The Alveoli are the actual exchange sites of the gases. Up to this point, the air passages simply provide a method to get air (O2 & CO2) into and out of the lungs. No exchange of gasses has occurred.
Breathing (Ventilation) includes two processes: • • •
Movement of air (gases) into and out of the lungs. Exchange of gases between the lungs (alveoli) and the blood (pulmonary capillaries).
Diaphragm contracts causing pressure change in the chest cavity during breathing • An increase in breathing rate can be caused by an increase of carbon dioxide in the blood Emphysema: is a disease associated with smoking which results in a reduction in the number & elasticity of alveoli, enlargement and degeneration of alveoli resulting in decreased lung capacity . Patients will be put on oxygen. Smoking can interfere with ciliary action in the trachea. It can also lead to lung cancer. Healthy and Tarred Lung
The Circulatory System The Circulatory System is responsible for transporting materials throughout the entire body.
Vocabulary • • • • • • •
Arteries are tubes that carry blood away from the heart Veins are tubes that return blood to the heart Capillaries connect arteries and veins. They are tiny tubes that exchange food, oxygen and wastes between blood and body cells. Pulmonary circulation is the movement of blood between the heart and lungs Coronary circulation is the movement of blood from within the heart chambers to the heart tissues themselves Systemic circulation is the movement of blood between the heart and the rest of the body Interstitial fluid -‐ is an isotonic solution which bathes and surrounds the cells of multicellular animals.
Functions of the Circulatory System •
•
The circulatory system functions in the delivery of oxygen, Delivery of nutrient molecules Delivery of hormones removal of carbon dioxide, ammonia and other metabolic wastes 3 parts of the Circulatory system pulmonary circulation -‐ the lungs (pulmonary), coronary circulation -‐ the heart (coronary), systemic circulation -‐ the rest of the body (systemic)
Parts of the Circulatory System The circulatory System is divided into three major parts: • The Heart • The Blood • The Blood Vessels The Heart •
The Heart is an amazing organ. It's job is to pump your blood and keep the blood moving throughout your body.
Make up of the Heart •
• • • •
Heart is made up of 4 chambers: the separation of the right and left side of the heart( by the septum) provides the separation of oxygenated blood from deoxygenated blood. Right and Left Atrium Right and Left Ventricle Ventricles are larger than the atria Between the atrium and ventricles there are valves. The valves only open in one direction and prevent backflow of blood into the atrium. Blood is brought back to the heart by veins and carried away from the heart by Arteries The heart is made up of special muscle cells that can carry an electrical impulse called cardiac muscle
Cardiac Cycle The cardiac cycle consists of two parts: systole -‐ contraction of the heart muscle (ventricles) diastole -‐ relaxation of the heart muscle • Atriums contract while ventricles relax. • Ventricles contract while Atriums relax • Heart valves limit flow to a single direction. One heartbeat, or cardiac cycle, includes atrial contraction and relaxation, ventricular contraction and relaxation, and a short pause •
Flow of Blood though the Heart • • • • • • • •
Right Atrium – deoxygenated blood Right Ventricle – deoxygenated blood Pulmonary artery – deoxygenated blood(blood goes to the lungs) LUNGS – Deoxygenated Oxygenated Pulmonary vein – oxygenated blood Left Atrium – oxygenated blood Left Ventricle – oxygenated blood Aorta – oxygenated blood to body
The flow of blood to and from the lungs in called pulmonary circulation.
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lub-‐DUB, lub-‐DUB, lub-‐DUB. Sound familiar? If you listen to your heart beat, you'll hear two sounds. These "lub" and "DUB" sounds are made by the heart valves as they open and close.
The Blood The blood is an amazing substance that is constantly flowing through our bodies. Your blood is pumped by your heart. Your blood carries nutrients, water, oxygen and waste products to and from your body cells. Your body has about 5.6 liters (6 quarts) of blood. This 5.6 liters of blood circulates through the body three times every minute. Make up of Blood • • • •
Plasma • •
Plasma is 90% water and 10% dissolved materials including proteins, glucose, ions, hormones, and gases. It acts as a buffer, maintaining pH near 7.4. Plasma contains nutrients, wastes, salts, proteins, etc.
Red Blood Cells
• • • • •
Red Blood Cells are responsible for carrying oxygen and carbon dioxide. Red Blood Cells pick up oxygen in the lungs and transport it to all the body cells. After delivering the oxygen to the cells it gathers up the carbon dioxide and transports carbon dioxide back to the lungs where it is removed from the body when we exhale. There are about 5,000,000 Red Blood Cells in ONE drop of blood. Life-‐span of an erythrocyte is only 120 days, after which they are destroyed in liver and spleen.
White Blood Cells (leukocytes )
• • • •
are larger than erythrocytes, (red blood cells) have a nucleus, and lack hemoglobin. They function in the cellular immune response.( fight off bacterial & viral infections) White blood cells (leukocytes) are less than 1% of the blood's volume.
Type of WBCs •
There are five types of leukocytes: Neutrophils enter the tissue fluid by squeezing through capillary walls and phagocytozing foreign substances. Macrophages release white blood cell growth factors, causing a population increase for white blood cells. Lymphocytes fight infection. T-‐cells attack cells containing viruses. B-‐cells produce antibodies. Antigen-‐antibody complexes are phagocytized by a macrophage. White blood cells can squeeze through pores in the capillaries and fight infectious diseases in interstitial areas
Platelets
Platelets are much smaller than the red blood •
Platelets are blood cells that help stop bleeding. When we cut ourselves we have broken a blood vessel and the blood leaks out. 1. In order to plug up the holes where the blood is leaking from the platelets start to stick to the opening of the damaged blood vessels. 2. As the platelets stick to the opening of the damaged vessel they attract more platelets, fibers and other blood cells to help form a plug to seal the broken blood vessel. When the platelet plug is completely formed the wound stops bleeding. Platelets survive for 10 days before being removed by the liver and spleen. Hemophilia – inability to clot – bleeders disease
Where are the blood cells made? • •
In your bone marrow. The Red Blood Cells are made in the red marrow and White Blood Cells and Platelets are made in the yellow marrow. Bone marrow is a soft tissue inside of our bones that produces blood cells.
• The Blood Vessels • • •
Arteries – carry blood AWAY from heart, thick walls, has the highest systolic & diastolic blood pressure Capillaries – Place were gas exchange (and materials) takes place between the blood and body tissues Veins – Carry blood BACK to the heart, has valves to counteract gravity and allow blood flow from legs to heart
Arteries: to determine heart rate, count the number of pulsations per minute in an artery • • • • • • • •
Arteries are blood vessels that carry oxygen rich blood AWAY from the heart. Remember, Arteries Away, The aorta, the largest artery in the body, is almost the diameter of a garden hose.. Arterial walls are able to expand and contract with the heart as it pushes blood through the body The aorta is the main artery leaving the heart. The pulmonary artery is the only artery that carries oxygen-‐poor blood. The pulmonary artery carries deoxygenated blood to the lungs. Arterioles are small arteries that connect larger arteries with capillaries. Small arterioles branch into collections of capillaries known as capillary beds.
Capillaries • • • •
Capillaries are tiny blood vessels. Only 1 RBC fits though at a time Capillaries are only 1 cell thick Capillaries connect arteries to veins. Food substances (nutrients), oxygen and wastes pass in and out of your blood through the capillary walls.
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Capillaries, on the other hand, are so small that it takes ten of them to equal the thickness of a human hair
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Capillaries are thin-‐walled blood vessels in which gas exchange occurs. In the capillary, the wall is only one cell layer thick. Capillaries are concentrated into capillary beds.
Nutrients, wastes, and hormones are exchanged across the thin walls of capillaries
Veins • • • •
Veins carry blood back toward your heart. Veins carry blood from capillaries to the heart. With the exception of the pulmonary veins, blood in veins is oxygen-‐poor. The pulmonary veins carry oxygenated blood from lungs back to the heart. Venules are smaller veins that gather blood from capillary beds into veins. The veins have valves that prevent back-‐flow of blood.
The actions of muscles to propel blood through the veins
The Lymphatic System: maintenance of proper levels of intercellular fluid
Different names for the SAME FLUID*** Blood plasma is the watery part of human blood. Interstitial fluid (intercellular fluid) is the fluid found surrounding all the cells of the body Lymph fluid is found in lymph vessels **** These 3 different fluids are the same fluid just with different names depending on where the fluid is located. (blood plasma = Lymph = Interstitial fluid) The lymphatic system It transports a watery clear fluid called lymph = interstitial fluid . This fluid distributes immune cells and other factors throughout the body. It also interacts with the blood circulatory system to drain fluid from cells and tissues. The lymphatic system contains immune cells called lymphocytes, which protect the body against antigens (viruses, bacteria, etc.) that invade the body.
Main functions****** The lymphatic system is composed: lymph vessels lymph nodes organs The functions: to collect and return interstitial fluid, including plasma protein to the blood, and thus help maintain fluid balance to defend the body against disease by producing lymphocytes (B-‐cells, and T-‐cells) Lymph organs Lymph organs include the bone marrow, lymph nodes, spleen, and thymus. Precursor cells in the bone marrow produce lymphocytes (white blood cells). Lymph Nodes Their two basic functions are: Filtration – macrophages destroy microorganisms and debris, bacteria and dead cells are removed from circulatory fluid Immune system activation – monitor for antigens and mount an attack against them
“X” are lymph nodes throughout the body
Spleen Largest lymphoid organ, located on the left side of the abdominal cavity beneath the diaphragm Functions stores disease-‐fighting components of the immune system (lymphocytes) Immune surveillance and response Cleanses the blood – takes out old and defective red blood cells Filtering Lymph nodes are filters of the lymph The spleen is a filter for old red blood cells Disorder of the Lymphatic System Lymphoma is a group of cancers that affect the cells that play a role in the immune system, and primarily represents cells involved in the lymphatic system of the body. They often originate in lymph nodes, presenting as an enlargement of the node (a tumor).
Immune System 3 Lines of Defense First line – • Skin The skin cannot be penetrated by most organisms unless it already has an opening, such as a nick, scratch, or cut. • Mechanically Pathogens are expelled from the lungs by ciliary action as the tiny hairs move in an upward motion; coughing and sneezing abruptly eject both living and nonliving things from the respiratory system The flushing action of tears, saliva, and urine also force out pathogens, as does the sloughing off of skin. • • Sticky mucus in respiratory and gastrointestinal tracts traps many microorganisms.
Second Line • Inflammation is characterized by redness and swelling • Inflammation is stimulated by chemical factors released from damaged cells. The increased blood flow causes puffiness, warmth, and attracts phagocytes (Neutrophils/Macrophages) • Macrophages are giant white blood cells that ingest large numbers of bacteria. – Developed from monocytes As the inflammation response proceeds, the phagocytes ingest the pathogens and any damaged tissue • • Pus – a mixture of dead WBCs (phagocytes), dead cells, bacteria and body fluid. Pus is either brained or absorbed by the body Third Line • When the first two systems fail to stop the pathogen the immune system is the last line of defense. • The immune system Recognizes the pathogen (virus, bacteria) Attacks Destroys Remembers • This is done by creating antibodies and specialized cells that destroy pathogens • Unlike the first two lines of defense the immune system is specific for each pathogen • Immunity – the ability to fight infection through the production of antibodies or cells that inactivate pathogens
Antigens • •
Antigen – ANY substance that causes an immune response. Viruses and microorganisms have substances on their outer surfaces that are antigens. Most antigens are proteins. Humans have a unique combination of proteins that no other human has. As a result transplanted tissue will act as an antigen. Reaction to transplanted organs: The transplanted organ has foreign antigens (proteins from another person). This causes the patient’s body to produce antibodies against the transplanted tissue/organ. The antibodies will destroy the new organ, this is called rejection of the organ. To increase chances for a successful organ transplant, the person receiving the organ should be put on medications to reduce their immune response to the new organ. These drugs will reduce the risk of rejection of the donated organ by the organ transplant patient. Rejection occurs when a person produces antibodies against the foreign antigens.
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The job of the immune system is to attack and destroy any antigens. If an organ or tissue produced by the patient’s stem cells was used for transplant, it would not be rejected. Since the organ was produced from the patient’s own stem cells, the proteins in the tissue wouldn’t be foreign to the body, so the immune system would not attack it.
Lymphocytes
Lymphocytes are WBCs that recognize specific antigens and either produce antibodies or kill foreign cells directly
Primary Immune Response •
When an antigen enters your body for the first time your immune system goes through the primary immune response The first 5 days following exposure to the antigen there is no measurable amounts of antibodies or specialized immune cells. Over the next 10-‐15 days there is a gradual rise in the levels of these products
Secondary Immune Response If an antigen enters the body for second time the response is much more rapid. With 1 to 2 days after infection of antigen, high levels of antibodies and immune cells are present in blood. White blood cells role: Protects the body against pathogens(bacteria, virus) •
Diagram shows a WBC engulfing/ingesting a bacterial cell
Engulf pathogens (surround & ingest) Produce antibodies Mark invaders for destruction by producing specialized molecules (phagocytes) Remember antigens from past exposures (which speeds up antibody production with a second exposure)
Active Immunity • • •
•
Active immunity: being infected by a live antigen (bacteria/virus) causing a primary immune response. (Memory B and T cells) Active immunity is also developed though a vaccination. Vaccinations consist of dead or weakened bacteria or viruses that cause an immune response but do not make an individual sick. Ex. small pox , chicken pox, flu vaccine Vaccines stimulate antibody production to help prepare the body to fight future invasions of disease causing organisms. If the organisms enter the body, the antibodies will be there to attack and kill it. Vaccines prevent people from getting the disease.
Passive Immunity • • •
Passive (borrowed) immunity : due to acquiring preformed antibodies from another individual. Example: immunized person gets tetanus shot after stepping on rusty nail. Shot consists of antibodies to the tetanus toxin made in the body of some animal (e.g. horse). Provides immediate protection, but will not last. Passive immunity typically lost after 6 months. Newborn children do not yet have active immunity. For first 6 months, don't get many diseases, protected by mother's antibodies passed to blood system of newborn before birth. After 6 months, infant must rely on its immune system to "learn" and acquire immunity to series of diseases.
Why doesn’t a person get sick right after the pathogen (bacteria, virus) enters the body? After a pathogen (causes disease or illness) enters the body the person may not have symptoms immediately. It takes time for the pathogen to reproduce & produce enough toxins to make you sick. Pathogens can interfere with normal life functions.
Antibodies & Antigens • • •
Antigens are "foreign" substances that induce some kind of immune response. Antibody or immunoglobulin is a large Y-‐shaped protein used by the immune system to identify and neutralize foreign objects like bacteria and viruses. Each antibody recognizes a specific antigen on the surface of the bacteria or virus
Vaccinations consist of dead or weakened bacteria or viruses that cause an immune response but do not make an individual sick.
Allergy: Immune system produces antibodies /chemicals against a usually harmless substance (antigen) • •
• • •
Allergy is a rapid overreaction to an antigen that is not normally harmful Allergy common symptoms: Runny nose Swollen, ichy eyes Sneezing, coughing A rash These symptoms are causes by the release of histamine which causes an inflammatory response Antihistamines are used to counter these effects Severe allergic reactions can lead to the swelling in the throat which will block the airway.
HIV and AIDS HIV = Human Immunodeficiency virus AIDS = Acquired Immune Deficiency syndrome When HIV enters the body the immune system recognizes it as an antigen and responds but the body defenses are unsuccessful. The immune response is weakened by the HIV infection • HIV infects Helper T- cells It can stay there for months or years without producing any symptoms • When HIV becomes active it reproduces and destroys the helper T- cells. This weakens the immune system and the body cannot fight infections. (HIV AIDS) • The body becomes unable to defend itself against pathogens and cancerous cells because of a weakened immune system. • HIV can also attacks the nervous system and can cause memory loss, partial paralysis, or mental disorder How is HIV Spread • • •
HIV is primary a sexually transmitted disease ANY intimate sexual contact that involves the exchange of body fluids. (except deep kissing) • Blood to blood contact • Sharing dirty needles • HIV can be transmitted from a mother to an unborn baby Prevention •
• • • •
ABSTINENCE Condoms – help but do not eliminate the chance of getting HIV Not using intravenous drugs Do not come into contact with someone's blood without protective gear.
Autoimmune diseases • •
The immune system fails to recognize some body cells as self. Makes antibodies against self cells and the immune system attacks self-‐cells. autoimmune diseases: juvenile diabetes – immune system attacks insulin producing cells Multiple sclerosis – immune system attacks the fatty covering of the nerve cells
Muscular system
How Muscles and Bones Interact: locomotion (movement) is the interaction between the endoskeleton & muscles 1. Skeleton muscles generate force and produce movement only by contracting or pulling on body parts.
2. Individual muscles can only pull; they cannot push.
3. Skeleton muscles are joined to bone by tough connective tissue called tendons.
4. Tendons are attached in such a way that they pull on the bones and make them work like levers. The movements of the muscles and joints enable the bones to act as levers. 5. Most skeletal muscles work in pairs. 6. When one muscle or set of muscles contracts, the other relaxes.
Involuntary Muscles • •
Involuntary muscles are muscles that are not under your conscious control Involuntary muscles are responsible for activities such as breathing and digesting food
Voluntary Muscles
Voluntary muscles are under your control, you cause your body to move •
Voluntary muscles are used when you smile, turn a page in a book, get out of your chair etc.
Types of Muscles • • •
There are three types of muscle tissue – skeletal muscle, smooth muscle, and cardiac muscle The skeletal muscles are voluntary muscles The smooth muscle and the cardiac muscle are involuntary
3 types of muscle under microscope
Skeletal Muscle •
Skeletal muscles help you move (locomotion), they are attached to the bones of your skeleton
• • •
At the end of the skeletal muscle is a tendon, which is a strong connective tissue that connects the muscle to the bone. Skeletal muscle cells appear banded, or striated One characteristic of skeletal muscles is that they react very quickly
Smooth Muscle • •
• •
Smooth muscles are muscles that you do not control. Smooth muscles can be found inside of many internal organs of the body, such as the walls of the stomach and blood vessels Unlike skeletal muscles, smooth muscles are not striated. smooth muscles react more slowly and tire more slowly
Cardiac Muscle • • • •
Cardiac muscle is only found in the heart Cardiac muscle is involuntary Cardiac muscles are striated Cardiac muscles do not get tired and they contract repeatedly
Skeletal System Bones -‐ the organs of the skeletal system. • The human skeleton(endoskeleton) has two divisions Axial skeleton – Consist of the skull, vertebrate column, and the rib cage The Appendicular Skeleton -‐ Consist the bones of the arms and legs, shoulder, and the pelvic girdle . • The Skeleton of Humans is composed of a special connective tissue called BONE • There are 206 bones in the human body
Functions of the Skeletal System • •
support -‐ it forms the body's framework to support the muscles and organs. protection -‐ the skeletal systems protects by 1) forming the bony cavities around organs,
– the thoracic cavity protects the heart and lungs – the cranial cavity protects the brain. 2) the yellow marrow in bones produces white blood cells which protect against invading microorganisms. The red marrow in bones produces red blood cells • movement -‐ bones form joints which provide levers for movement such as walking, lifting, etc. • hematopoiesis (blood cell production) -‐ the red marrow produces red blood cells. • mineral storage and homeostasis -‐ the skeleton forms a reservoir of minerals, especially calcium, for maintenance of homeostasis. Cartilage: cushions joints upon impact, provides flexibility of structures, & makes up most of the embryonic skeleton
Joints • • • • • •
JOINTS WHERE TWO BONES MEET Cartilage is responsible for keeping bones far enough apart so they do not rub against each other as they move. At the same time, joints hold the bones in place. Joints work by attaching muscles which work in in pairs -‐ ANTOGONISTIC MUSCLES -‐ flexors & extensors Muscles attach to bone via connective tissue called TENDONS Bones attach to bones via connective tissue called LIGAMENTS
A: tendon
B: muscle
C: ligament
There are two kinds of joints: 1. IMMOVABLE JOINT
THEY ARE OFTEN CALLED FIXED JOINTS, AND ALLOW NO MOVEMENT BETWEEN BONES. – – –
These joints are interlocked and held together by Connective Tissue, or they are fused together. The places where the bones of the SKULL meet (SUTURE) meet are examples of immovable joints. Immovable joints are located in bones of the skulls and the ribs
2. MOVABLE JOINT MOST OF THE JOINTS OF THE BODY ARE FREELY MOVABLE JOINTS. –
– Types of Joints
In Freely Movable Joints, the ends of the bones are covered with a layer of Cartilage that provides a smooth surface at the joint. Joints are a place where two or more bones come together. Examples are the ball-‐and-‐socket, pivot, hinge, and gliding
Moveable Joints Ball-‐and-‐socket joint –
Ball-‐and-‐socket joints allow the greatest range of motion. They can be found in the shoulder where the top of the arm bone fits into the deep, bowl-‐like socket of the scapula (shoulder blade).
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This joint allows you to swing your arm freely in a circle, your hips also have ball-‐and-‐socket joints
Moveable Joints Hinge joint •
Permits a back-‐and-‐forth motion. The Knee enables your leg to flex and extend. The Elbow, which allows you to move your forearm toward and away from your body.
Moveable Joints Pivot Joint – –
A pivot joint allows one bone to rotate around another A pivot joint can be found in the top of your neck, which gives you limited ability to turn your head from side to side
Moveable Joints Gliding Joint •
A gliding joint allows one bone to slide over another bone The joint located in your wrist is an example of a gliding joint this joint enables you to bend and flex your wrist, as well as make limited side-‐to-‐side motions.
Disorders of the musculoskeletal system Arthritis Arthritis affects the musculoskeletal system, specifically the joints. It is the main cause of disability among people over fifty-five years of age in industrialized countries.
What causes arthritis? In order to better understand what is going on when a person suffers from some form of arthritis, let us look at how a joint works.
Basically, a joint is where one bone moves on another bone. Ligaments hold the two bones together. The ligaments are like elastic bands, while they keep the bones in place your muscles relax or contract to make the joint move. Cartilage covers the bone surface to stop the two bones from rubbing directly against each other. The covering of cartilage allows the joint to work smoothly and painlessly. A capsule surrounds the joint. The space within the joint - the joint cavity - has synovial fluid. Synovial fluid nourishes the joint and the cartilage. The synovial fluid is produced by the synovium (synovial membrane) which lines the joint cavity. If you have arthritis something goes wrong with the joint(s). What goes wrong depends on what type of arthritis you have. It could be that the cartilage is wearing away, a lack of fluid, autoimmunity (your body attacking itself), infection, or a combination of many factors.
Tendonitis Tendonitis is an overuse injury of the ropelike structure that connects our muscles to our bones. That's what a tendon is. It occurs most commonly in those muscles that cross two joints. The common examples being tennis elbow, in which the forearm muscle crosses both the elbow and the wrist, or a calf muscle, in which the muscle crosses both the knee and the ankle joint, resulting in Achilles tendonitis.
The best way to prevent tendonitis is to work on flexibility and strength of those involved muscles. Hence, when we talk about tendonitis, the factors that predispose that muscle to injury would be inflexibility or tight muscles as well as a poorly conditioned or weak muscle. When treating tendonitis, we start with the acronym RICE: rest, ice, compression -- a sleeve or a wrap -- and elevation of the injured tendon or joint. That's a good place to start. Once that inflammation -- the pain, the swelling -- has settled down, oftentimes in three or four days after the injury, then we can work on rehabilitating that muscle and that tendon, and we focus again on flexibility, stretching the muscle, as well as then strengthening and conditioning the muscle, oftentimes in hopes of preventing the tendonitis from recurring.
Nervous System The Nervous System has TWO Major Divisions • •
The Central Nervous System The Peripheral Nervous System
The Central Nervous System (CNS) • • • •
The Central Nervous System (CNS) consist of the Brain and the Spinal Cord. The spinal cord carries messages from the body to the brain, where they are analyzed and interpreted. Response messages are then passed from the brain through the spinal cord and to the rest of the body. Both the brain and the spinal cord are encased in bone.
Brain • •
Brain and spinal cord float in a fluid known as cerebrospinal fluid. This fluid cushions against shock. Major parts of the Brain: Cerebrum (Cerebral Cortex) Cerebellum Medulla Oblongata
• •
Thalamus – relay center between Brain and spinal cord Hypothalamus – controls body temperature, blood pressure, and emotions
Cerebral cortex •
3 major Functions Sensory areas that receive impulses from sense receptors (Eyes, ears, taste, nose, pain, pressure, heat/cold, touch) Motor areas that start impulses that are responsible for all voluntary movement Associative areas of the brain are responsible for memory, learning and thought
A: Cerebrum – reasoning, thought speech, all senses, start of voluntary movement
B: Spinal cord-‐ reflex actions
The Cerebellum • • • •
Controls all voluntary movements and some involuntary The cerebellum helps with balance, rate of muscle contraction, and the muscles position in relation to gravity Allows for smooth orderly movement Also plays a roll in sensory perception to maintain balance (inner ear)
X: cerebellum, coordination & balance, smooth orderly movement
Medulla Oblongata • •
Connect the spinal cord to all other parts of the brain Control involuntary activities Breathing Heartbeat Blood flow
coughing
An increase of carbon dioxide in the blood would stimulate the respiratory center of the brain. Impulses would be sent by the medulla to the diaphragm , increasing the rate of breathing.
THE SPINAL CORD: is protected by the vertebrae • • •
2 Important Functions Connects the nerves of the peripheral nervous system with the brain Controls certain reflexes which are automatic responses The spinal cord is continuous with the brain and emerges from an opening at the base of the skull. It is a dorsal nerve cord with connecting nerves
Divisions of the Peripheral Nervous System • •
Somatic Nervous System – This system is responsible for body movements over which the individual has some conscious awareness or voluntary control. Ex: muscles used for writing Autonomic Nervous System – This system is responsible for involuntary activities. 2 divisions Sympathetic Parasympathetic
A: Endocrine system
B: Central nervous System
C: Autonomic
Sympathetic “Fight or Flight” Nervous System • •
The sympathetic nervous system prepares the body for sudden stress For example if you see a robbery taking place. When something frightening happens, the sympathetic nervous system takes over makes the heart beat faster diverts blood to your muscles and chest
•
makes the pupils dilate causes the adrenal glands at the top of the kidneys to release adrenaline, to give extra power to the muscles for a quick getaway. This process is known as the body's "fight or flight" response.
Parasympathetic “Sit and Digest” nervous system • • • •
It prepares the body for rest. Slows heart rate It also helps the digestive tract move along so our bodies can efficiently take in nutrients from the food we eat. Opposite of the sympathetic
REFLEXES: Interneuron relays impulses directly from a sensory neuron to a motor neuron. A reflex is an involuntary response to a STIMULUS. Reflexes are very fast, and Most Reflexes Never Reach the Brain. The reflex arc is an automatic, involuntary reaction to a stimulus. When the doctor taps your knee with the rubber hammer, she/he is testing your reflex (or knee-‐jerk). If a motor neuron in a reflex arc is damaged, contraction of a muscle will not occur. Route of impulse in a reflex arc: Receptor-‐> sensory neuron-‐> interneuron-‐> motor neuron-‐> effector •
X: an interneuron, transmits impulses from a sensory neuron to a motor neuron
How do signals go from the brain to the other body parts?
Nerve impulses
Nerve Impulse Nerves •
The Nervous System CONTROLS and COORDINATES ALL ESSENTIAL FUNCTIONS of the human body.
• •
The Nervous System RECEIVES and RELAYS information about activities within the body and monitors and responds to INTERNAL and EXTERNAL CHANGES. The functioning Nervous System is an enormous network of "one-‐way streets
The Nervous System has FOUR FUNCTIONS that enable the body to respond quickly 1. Gathers information both from the outside world and from inside the body. (sensory) 2. Transmits the information to the processing area of the brain and spinal cord. 3. Processes the information to determine the best response. (integrative) 4. Sends information to muscles, glands, and organs (effectors) so they can respond correctly. Muscular contraction or glandular secretions. (motor)
Cell A causes the cells at B to contract, causing movement of an arm or leg.
Pathway of messages being sent across neurons(nerve cells)
Enlarged area shows a receptor molecule at the end of a neuron. Receptor molecules play an important role in communication between cells. Neurons transmit electrochemical messages
Nerve cell Y contains receptor molecules for substance A, this process represents cellular communication. The space between the nerve cells is called a synapse.
Acetylcholine is a chemical (neurotransmitter) secreted at the ends of nerve cells. This chemical helps to send nerve signals across the synapse. After the signal passes across a synapse, an enzyme breaks down the acetylcholine. LSD is a drug that blocks the action of this enzyme causing nerve signals not to be turned off. Path of a nerve inpulse: ear hear phone ring message goes across the nerves to the brain brain sends message to hand to pick up phone
How do drugs affect cellular communication in the brain? Opiate drugs such as heroin, imitate endorphins, which is a type of neurotransmitter that is naturally produced in the brain. Heroin gives the brain false signals because the neurons respond to the heroin as if it was a neurotransmitter. HSD: Acetylcholine is a chemical that is secreted at the ends of nerve cells (neurotransmitters). This chemical helps to send nerve signals across synapses (spaces between nerve cells). After the message is passed the chemical is broken down by an enzyme. LSD blocks the action of an enzyme that breaks down Acetylcholine. This will cause cell communication to be disrupted and nerve signals would not be turned off.
Endocrine System
Nervous System controls the Endocrine System • •
The endocrine system, along with the nervous system, functions in the regulation of body activities. (Maintaining Homeostasis) The nervous system acts through electrical impulses and neurotransmitters to cause muscle contraction and glandular secretion.
Nervous VS Endocrine • •
The nervous system coordinates rapid and precise responses to stimuli using action potentials. The endocrine system maintains long-‐term control using chemical signals. The endocrine system works in parallel with the nervous system to control growth and maturation along with homeostasis
Endocrine system • •
The endocrine system acts through chemical messengers called hormones that influence growth, development, and metabolic activities. The action of the endocrine system is measured in minutes, hours, or weeks and is more generalized than the action of the nervous system.
Endocrine Glands
• The endocrine glands do not have ducts to carry their product to a surface. (ductless glands) • Only endocrine glands produce Hormones • The secretory products of endocrine glands (hormone) are secreted directly into the blood The Hormone is transported throughout the body, by blood, where they influence only those cells that have receptor sites for that hormone.
Chemicals = hormones
A: Pituitary B: Thyroid E: Pancreas F: Ovary
C: Parathyroid D: Adrenal gland G: Testes(Testical)
Hormones • • •
2 Types of hormones Steroid Hormones – are lipid like carbon rings These hormones are able to pass though the cell membrane. This type of hormones is produced in the adrenal glands and the Gonads (testis and ovaries) Protein hormones – made up of amino acids
-‐ These hormones cannot pass though the cell membrane because they cannot dissolve in fats. Ex. Insulin
Pituitary Gland • • • •
The pituitary gland is often called the master gland because hormones released from the pituitary gland control other endocrine glands in the body. It is located at the base of the brain. A stalk links the pituitary to the hypothalamus, which controls release of pituitary hormones. The pituitary gland has two lobes: the anterior lobe (front)
Major Hormones of the Anterior Pituitary
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Thyroid simulating hormone: (TSH) stimulates the production and release of thyroxin from the thyroid gland Adrenocorticotropic Hormone: (ACTH) stimulates the production and release of hormones of the adrenal glands Growth Hormone: (GH) controls the release of GH into the body, which causes bones to grow longer Follicle Simulating Hormone: (FSH) stimulates the development of egg cell in females and controls sperm production in males Luteinizing Hormone: (LH) Causes the release of an egg in the female and controls the production of sex hormones in both males and females Prolactin: Stimulates the secretion of milk after birth only found in females
•
Major Hormones of the Posterior Pituitary
• • • • •
• •
The posterior pituitary stores and releases hormones into the blood. 2 Major Hormones: Vasopressin (Antidiuretic Hormone -‐ ADH) controls water balance in the body and blood pressure. Oxytocin is a small peptide hormone that stimulates uterine contractions during childbirth.
Job of the Hypothalamus : produce hormones that affect the functioning of the pituitary gland • • • •
The Hypothalamus contains neurons that control releases from the anterior pituitary. The Hypothalamus is the major link between the nervous system and the endocrine system The hypothalamus regulates homeostasis. It has regulatory areas for thirst, hunger, body temperature, water balance, and blood pressure, and links the nervous system to the endocrine system
The Adrenal Glands • • •
The nerves of the sympathetic nervous system regulate the release of adrenal hormones The adrenal glands secrete two hormones: epinephrine (adrenalin – 80%) and norepinephrine. (noradrenalin – 20%) “Fight or Flight hormones ,( in times of emergency secrete hormones which increase glucose level of blood and speeds up actions of the circulatory & respiratory system)
The Thyroid Gland: requires a supply of iodine to synthesize (make) its hormone thyroxin The thyroid gland is located in the neck. Thyroid stimulating hormone (TSH) from the anterior pituitary causes thyroid hormones to be released. Almost all body cells are targets of thyroid hormones. • Thyroid hormone increases the overall metabolic rate regulates growth and development as well as the onset of sexual maturity Goiter: enlargement of thyroid due to a diet low in iodine • •
Parathyroid Gland: secrete hormones that influence proper development of bones & teeth a long with Thyroid • •
These are tiny oval glands imbedded in the thyroid gland Secrete parathyroid hormone called parathormone which regulates calcium and phosphate levels in the body. Calcium is necessary for proper growth and health of bones, teeth, blood clotting, and muscle contraction Phosphate is found in bones, and many compounds including DNA, ATP, and RNA
The Pancreas: cells within this gland secrete hormones that maintain normal levels of simple & complex carbohydrates •
The pancreas is made up of exocrine and endocrine Excocrine glands that secrete digestive enzymes into the small intestine Endocrine glands secrete the hormones insulin and glucagon, which regulate blood glucose levels. An increase of insulin in the blood will cause a decrease of glucose in the blood. Glucagon stimulates the release of sugar from the liver into the blood when blood sugar levels are low.
•
Digestion prompts the release of insulin, which causes cells to take up glucose, and liver and skeletal muscle cells to form the carbohydrate glycogen.
Thymus Gland
• • • •
The Thymus is an endocrine gland and is located in the upper chest near the heart As a young child the thymus helps in the processing of lymphocytes The thymus secretes thymosin throughout childhood The thymus appears to have little or no function in adults
The Pineal Gland • •
The pineal gland is a pea shaped endocrine gland that is attached to the base of the brain It secretes melatonin which is thought to help control the human sleep cycles. Low levels of melatonin during the day and higher levels at night
Gonads •
Sex glands Ovaries in female – produce eggs and female sex hormones estrogen and progesterone
A: ovary, produces the hormones estrogen & progesterone Testes in male – produce sperm and male sex hormone testosterone
A: testicle, produces the hormone testosterone • • Both of these glands stimulate the development secondary sex characteristics when they are stimulated (puberty) In females this causes the broadening of the hips and development of breasts In males this cause the deepening of the voice, facial hair, body hair, and broader shoulders
Improper Functioning of Glands • •
Hypersecretion – When a gland secretes more hormone then normal Hyposecretion – When a gland secretes less hormone then normal
Negative feedback Loop
A high level of hormone 3 in the blood inhibits the production of hormone 2 • • • • • • • •
• •
Hypothalamus receptors monitor blood levels of thyroid hormones. Low levels of thyroxin cause the Hypothalamus to stimulate the anterior pituitary Hypothalamus stimulates the release of TSH-‐releasing hormone from the anterior pituitary. TSH travels to the thyroid where it promotes production of thyroid hormones, which in turn regulate metabolic rates and body temperatures. The increased levels of thyroid hormone in the blood stops the release of TSH from the hypothalamus and anterior pituitary gland stopping the thyroid from releasing too much thyroid hormone. This type of interaction between 2 hormones helps to maintain a balanced internal environment.
Feedback mechanism that helps maintain homeostasis (balanced internal environment)
Reproductive System Sexual Reproduction • • • • •
•
Sexual reproduction: A form of reproduction in which a new individual is produced by the union of nuclei of two specialized sex cells. In sexual reproduction new individuals are produced by the fusion of haploid gametes ( egg, sperm) to form a diploid zygote. Egg + Sperm = zygote Haploid (23 chromosomes)+ Haploid (23 chromosomes) = Diploid(46 chromosomes) Haploid cell –½ the normal number of chromosomes – in humans each egg & each sperm have 23 chromosomes Diploid cell – normal number of chromosomes ( in humans 46 chromosomes)
Sperm fertilizing an egg
Human Reproduction • • • • •
Sexual Reproduction in humans is the combination of egg and sperm. Sperm are male gametes (haploid), formed in the testes ova (ovum singular -‐egg) are female gametes. (haploid), formed in the ovaries You get 1/2 your chromosomes from Dad and the other 1/2 from mom. Haploid (1/2) + Haploid (1/2) = Diploid (1)
Advantages and Disadvantages of sexual reproduction • •
Advantage: Sexual reproduction offers the benefit of generating genetic variation among offspring, which enhances the chances of the population's survival. Disadvantage: Costs of this process include the need for two individuals to mate, courtship rituals, as well as a number of basic mechanisms described later.
Human Reproduction and Development •
Human reproduction employs internal fertilization
•
Gonads are sex organs that produce gametes. Male gonads are the testes, which produce sperm and male sex hormones. Female gonads are the ovaries, which produce eggs (ova) and female sex hormones.
The Male Reproductive System .
Path of sperm: D BC
A. Testicle: produces Sperm(transports genetic material), produces testosterone (male sex hormone) which produces male characteristics ( muscle development, deep voice, facial hair…) and affects sperm production. Meiosis occurs here to form the sperm. Testicles are surrounded by the scrotum. The testicles are considered part of the endocrine system because it produces the hormone testosterone and part of the reproductive system for producing sperm.
Scrotum: The scrotum is contained within the abdominal cavity in the embryonic stage. Shortly before birth, they come
down and remain outside throughout life. This is because the testes cannot produce sperms at the body temperature. A temperature 2-3 degrees lower is ideal for the production of sperms. The scrotal sacs hang loose when it is hot and when it is cold the skin of the scrotal sacs contracts and this keeps them in close contact with the body.
B. Seminal Vesicle: behind the bladder, secretes a fluid that combines with sperm to produce semen. C. Vas deferens : a duct that connects the testes to the urethra. Sperm travel through this to exit the body. If there is a blockage here, sperm would not be transported to the urethra. D. Bladder: stores urine E. Prostate Gland: secretes an alkaline fluid into urethra which mixes with the semen.. F Cowpers glands: secretes a lubricating fluid into the urethra just before it enters the penis. The secretions of these glands make the sluggish sperms more active and help in the passage of sperms through the duct system and then in the ejaculation.
G. Urethra: carries urine (excretory system) or semen(reproductive system) outside of the body H. Penis: is a muscular organ containing erectile tissue. The tissue is richly supplied with blood vessels. On sexual stimulation the penis is gorged (supplied) excess with blood which causes it to become erect. During sexual intercourse, the penis is inserted into the vagina of the females before ejaculation. Ejaculation is the release of sperms by the penis to the outside. Sperm: male sex cell (gamete), produced by meiosis in testes, contains 23 chromosomes (haploid),transports genetic material(genes, DNA)
Path of sperm: Testicles-‐ Vas deferens-‐ urethra
The Female Reproductive System • The female gonads, ovaries, are located within the lower abdominal cavity. The ovary contains many follicles composed of a developing egg surrounded by an outer layer of follicle cells.
Female Sexual Structures: Reproductive cycle stops as women age due to decrease of sex hormones 1. Vagina – birth canal which leads to the outside of the body. 2. Cervix – Narrow neck of the uterus 3. Ovaries – Each month an egg(gametes) develops, matures and is released. Produces the sex hormones estrogen & progesterone . Considered part of endocrine system( produces Hormones) & reproductive system. Release of egg is called ” ovulation”. • • 4. Fallopian Tube or Oviduct – Carries the mature egg from the ovary to the uterus (most fertile time) The opening of the oviduct is lined with cilia that draws the released egg into the tube. Fertilization occurs here . • • • • •
Fertilization in the oviduct (fallopian tube)
Mitosis of the zygote starts in the oviduct
5.Uterus – thick walled, muscular, pear shaped organ. If egg is fertilized, embryo is implanted here & develops (support of fetus). If no pregnancy occurs, uterine lining breaks down each month & leaves body ”menstruation”
Placenta During pregnancy, the placenta will form in the uterus. The placenta forms from fetal tissue & uterine tissue. The placenta is essential to the embryo for the processes of nutrition , excretion and oxygen transport to the fetus. Harmful toxins can cross the placenta by diffusion.
Ovarian Cycles: The hormone FSH produced by the pituitary gland, helps the development of the ovarian follicle.
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After puberty the ovary cycles between a follicular phase (maturing follicles) and a luteal phase (presence of the corpus luteum).
Follicle stage: thickening & vascularization of uterine lining • Corpus luteum: ovarian tissue that surrounds each egg, it is called the ‘yellow bodied structure that secretes the hormone progesterone
• • •
These cyclic phases are interrupted only by pregnancy and continue until menopause, when reproductive capability ends.
The ovarian cycle lasts usually 28 days.
Oogenesis ( formation of gameters-‐eggs) •
Meiosis occurs in ovary, I egg & 3 polar bodies produced.
At birth each female carries a lifetime supply of developing oocytes (eggs) A developing egg (secondary oocyte) is released each month from puberty until menopause, a total of 400-‐500 eggs
Menstrual cycle Part 1: controlled by pituitary gland & ovaries • • • • •
Menstrual cycles vary from between 15 and 31 days. The first day of the cycle is the first day of blood flow (day 0) known as menstruation. (Menses) During menstruation the uterine lining is broken down and shed as menstrual flow. FSH and LH are secreted on day 0, beginning both the menstrual cycle and the ovarian cycle. Both FSH and LH stimulate the maturation of a single follicle in one of the ovaries and the secretion of estrogen. (Follicular phase) Rising levels of estrogen in the blood trigger secretion of LH, which stimulates follicle maturation and ovulation ( a mature egg is released by the ovary -‐day 14, or midcycle).
Menstrual cycle Part 2 LH stimulates the remaining follicle cells to form the corpus luteum, which produces both estrogen and progesterone. (luteal phase) • Estrogen and progesterone stimulate the development of the endometrium and preparation of the uterine inner lining for implantation of a zygote. (fertilized egg) • If pregnancy does not occur, the drop in FSH and LH cause the corpus luteum to disintegrate. The drop in hormones also causes the sloughing off of the inner lining of the uterus by a series of muscle contractions of the uterus Sequences of menstrual cycle: •
Follicle stage ovulation corpus luteum menstruation
Fertilization • • •
During intercourse 100s of millions of sperm are released into the vagina. This is to ensure that some sperm will survive and fertilize the egg Sperm swim through the cervix, up through the uterus, and in to the oviducts If there is an egg moving down the oviduct it may be fertilized by the sperm. If the fertilized egg implants in the wall of the uterus the corpus luetum will release large amounts of progesterone
Fertilization facts • • • • •
Sperm can live in the female reproductive system for 72 hours. Pregnancy can occur during menstruation. Progesterone is known as the pregnancy hormone. Only 1 sperm can fertilize an egg. Humans have 46 Chromosomes – 23 egg + 23 sperm = 46 new complete set
Mitosis (cell division) of the fertilized egg occurs in the oviduct (fallopian tube)
Differentiation: Embryonic cells will use different portions of their genetic information to become different cells of the body. Example: liver cells, heart cells, brain cells
Gender A baby's sex is determined at fertilization. A chromosome from the father's sperm determines whether the child is male or female. If an X chromosome is present the baby is a girl; if a Y chromosome is carried by the sperm instead, the baby is a boy. Twins
Occasionally two eggs are released by the ovary and fertilized by a different sperm. This results in fraternal twins who are different in appearance and may be of different sexes because their genes form from two eggs and two sperm cells. Rarely, one embryo splits into two and both cells develop separately, as identical twins, similar in appearance." They have the same genetic make-up and apparently the whole genetic message is the same in both of them. Nevertheless, they are obviously different human beings."2 Protection & Support During and after implantation the embryo develops a protective, fluid-filled capsule which surrounds and cushions the developing body to prevent injury. Embryo and fluid are enclosed in two membranes, an inner amnion and an outer chorion. The chorion is covered in rootlike tufts, some of which form the early placenta - an organ made by the baby and the mother which transfers nutrients from the mother's bloodstream and removes waste products from the child's, though mother's and baby's circulatory systems remain separate. The placenta also produces hormones to maintain the pregnancy. In the ninth month it will alter the mother's hormonal balance and triggers off the birth process - although we are still unsure what causes labor to begin. The baby is connected to the placenta by the umbilical cord, the lifeline channeling nourishment in and taking wastes out, which will be cut close to the baby's abdomen at birth and will leave the mark of the navel. During pregnancy the baby obtains oxygen from the mother's blood via cord and placenta, so does not drown in the surrounding fluid. Carbon dioxide (waste product from cellular respiration) passes through the placenta from the blood of the fetus to the blood of the mother. A pathogen passed from mother to fetus could cause an infection in the fetus The German measles is a virus which can cross the placenta from mother to fetus. Body development Exposure to toxins ( smoking ,pesticides, other chemicals) and alcohol during early stages of pregnancy can cause birth defects because essential organs form during early development. The endoskeleton of a human embryo is made up of mostly cartilage (connective tissue) Gestation: carrying of fetus in mother’s body. Time between fertilization & birth. Gestational period for humans is 9 months (38-40 weeks). Gestation ends with the birth.
Development of human: Fertilized egg tissues organs fetus
#1 Oviduct or Fallopian tube: fertilization occurs here #2 Uterine muscles: contracts and pushes baby out during labor. Estrogen will stimulate the production of extra blood vessels here #3 Uterus: Embryo develops into fetus, influenced by progesterone & estrogen during pregnancy. Uterine tissue combines with fetal tissue to form the placenta. #4 Vagina :
birth canal, fetus will leave the uterus and travel through the vagina during labor
#5 Umbilical cord:
connects baby to placenta
#6 Placenta : nutrient (nutrition) & Oxygen exchange from Mom to baby. Carbon dioxide & other waste products (excretion) exchange from baby to mom Blood systems of mom and baby are separate, but certain materials can pass from one another through the placenta by diffusion. #7 Amniotic fluid: protects & cushions the baby from shock
Fertilized egg- tissues- organs- fetus
Assisted Reproduction Technology What is ART? ► Group of high tech treatment methods to improve infertility. ► Techniques include In Vitro Fertilization Artificial Insemination Gamete Intra-‐Fallopian Transfer And many more
What is Infertility? ► Inability to conceive a baby after one year of unprotected intercourse. ► Affects the reproductive organs of both men and women. Infertility affects about 15% of couples in the United States
Factors Affecting Conception ► ► ► ► ►
Production of healthy sperm Healthy eggs by the woman Unblocked fallopian tubes The ability for the sperm to fertilize the egg The ability for the embryo to implant in the uterus
Causes of Infertility in Women The older a woman is the higher her chances of becoming infertile. Ovulation disorder Blocked fallopian tubes caused by a pelvic inflammatory disease or endometriosis (a condition that causes adhesions and cysts) Adhesions is scar tissue
Causes of Infertility in Men ► Azoospermia-‐lack of sperm production ► Inability to ejaculate normally ► Varicocele-‐ veins in the scrotum are enlarged which can heat the inside of the scrotum and can affect sperm production. ► Teratospermia-‐ increased percentage of abnormal shaped sperm
Most Common Choices of Treatment
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In Vitro Fertilization Artificial Insemination Frozen Embryos Gamete Intra Fallopian Transfer Zygote Intra Fallopian Transfer
Artificial Insemination ► Sperm is collected and placed into a woman’s vagina, cervical canal or in the uterus. ► Sperm can come from your partner or an anonymous donor.
In-‐Vitro Fertilization: USED FOR BLOCKED FALLOPIAN TUBE ► Procedure that involves retrieving eggs and sperm from the bodies of the male and female partners and placing them together in a laboratory dish to enhance fertilization.
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Fertilized eggs are then transferred (implanted) several days later into the female’s uterus where
implantation and embryo development will hopefully occur as in a normal pregnancy
Gamete Intra-‐Fallopian Transfer (GIFT)
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A mixture of a woman’s eggs and sperm are placed into the fallopian tube during a laparoscopy.
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Once inserted, fertilization is allowed to occur.
Frozen Embryos ► Embryos may be taken from an individual and stored for later use. ► Once ready to use, they can be thawed and then placed into the uterus. This allows a higher chance of pregnancy
Left-‐over Embryos
Typically, during fertility treatments, women may store fertilized eggs, embryos, as part of their treatment. Kept frozen for unanticipated catastrophe A kind of immortality Many major fertility centers have thousands of these-‐-‐10,000 per year nationally No federal agency oversees this Sometimes embryos are donated to infertile couples, but legal issues about parental rights persist.
Surrogacy Surrogacy occurs when I woman agrees to carry to term the fetus for another person. That fetus may be from the egg and sperm of the couple who want to raise the child or it may be donor eggs or donor sperm. What are the rights of the surrogate mother? Of the individuals who ask her to be a surrogate?
• • •
Sexually Transmitted Diseases Sexually transmitted diseases (STDs) cause over $7 billion to be expended for treatment. STDs can affect the sex partners, fetus, and newborn infants. STDs are grouped into three categories Category One • •
STDs that produce inflammation of the urethra, epididymis, cervix, or oviducts. Gonorrhea and chlamydia are the most common STDs in this category. Both diseases can be treated and cured with antibiotics, once diagnosed.
Category Two • • •
STDs that produce sores on the external genitals. Genital herpes is the most common disease in this class, affecting more than 25 million individuals in the US. Symptoms of herpes can be treated by antiviral drugs, but the infection cannot be cured. Syphilis is a bacterially caused infection, and can, if left untreated, cause serious symptoms and death. However, the disease is curable with antibiotics.
Category Three • This class of STDs includes viral diseases that affect organ systems other than those of the reproductive system. AIDS and hepatitis B are in this category. Both can be spread by sexual contact or blood. Infectious individuals may appear symptom-‐free for years after infection
Ecology •
Ecology is the study of interactions among organisms and between organisms and their environment.
Biosphere contains the combined portions of the planet in which life exists, including land, water, and air or atmosphere. Biotic – All living things that effect the environments Abiotic- the nonliving part of the environment Ex: light, temperature, water, gases, soil, minerals, PH •
• •
Levels of Organization • • •
Species is a group of organisms so similar to one another that they can breed. Population are groups of individuals that belong to the same species and live in the same area. Ex: All the goldfish in a tank or all the deer in the park
•
Communities are assemblages of the different populations that live together in a defined area. EX; all the insects, birds, mice, snakes, worms, bacteria & plants in a field
•
Ecosystem is a collection of all the organisms that live together in a particular place as well as their nonliving or physical environment. Ex: all the biotic and abiotic factors interacting in an area. For a stable ecosystem: there must be interrelationships & interdependencies among organisms Organisms within an ecosystem depend on the activities of biological catalysts
•
Biome is a group of ecosystems that have the same climate and similar dominant communities. Levels of ecological organization: Populationcommunitiesecosystembiosphere
Population: seagulls
Community: all the plants and animals
Ecosystem: All the plants, animals, PH, temperature and soil
•
Nutritional Relationships: Ecosystem
The transfer of nutrients from one organism to another within an
. The arrows indicate energy being transferred from one organism to the next as it is being eaten. The grass gets eaten by the mouse, and the mouse gets eaten by the snake & hawk
Energy Flow • • •
Sunlight is the main source of energy for life on Earth. Some types of organisms rely on the energy stored in inorganic chemical compounds. Autotrophs (producers) use energy from the sun to change inorganic compounds into complex organic molecules.
•
Energy Flow : Autotrophs-‐Synthesize their own food from inorganic compounds (carbon dioxide and
water) and energy from the sun
The best known autotrophs (plants) are those that harness the power of the sun through photosynthesis. They use this energy to convert carbon dioxide and water into oxygen and glucose. The second type of autotrophs use chemical energy to make carbohydrates. This is performed by several types of bacteria
Producers = Autotrophs •
Make their own food through photosynthesis.
•
Light energy photosynthesis chemical energy(sugar) respiration ATP (energy)
Energy Flow: Consumers Heterotrophs (consumers) rely on other organisms for their energy and food. (consume other organisms)
•
They are classified based upon what they eat and how they obtain food
Saprophytes: Organisms that live off dead organic matter, Examples: fungi, bacteria, yeast
Herbivores obtain energy by only eating plants. Examples: cows, mice, snails, rabbits •
Also known as “primary consumers” •
Carnivores obtain energy by eating animals. “ Secondary Consumers”
•
Predator: animal that kills other animals .
•
Scavenger: feeds on organisms that are already dead.
• • •
*Parasite: feeds off of living animals.
• Omnivores eat both plants and animals.
Detritivores feed on the remains of plants, animals and other dead matter. Decomposers breaks down organic matter into inorganic matter. •
Symbiosis : A relationship in which 2 organisms live together in close association
•
1. Commensalism: One organism benefits and the other is not harmed Barnacles and Whales
•
Barnacles need a place to anchor. They must wait for food to come their way. Some barnacles hitch a ride on unsuspecting whales who deliver them to a food source. This does not effect the whale in any way.
Oak Gall Wasps and Oak Trees: • • • •
The oak gall wasp stings the oak tree. the tree then grows a GALL which is a nest for the wasp’s babies. When the larva hatch, they eat their way out of the gall. Does not help or hurt the oak tree
2. Mutualism: both organisms benefit
Nitrogen fixing bacteria live in nodules on the roots of legumes. Bacteria create ammonia from nitrogen in
•
air, which is used by the plant to create amino acids and nucleotides. The plant provides the bacteria with
sugars.
E. coli living in human intestine: E. coli is a bacteria that helps breakdown sustances that our body can’t do on it’s own. The bacteria synthesize(make) vitamins used by humans a nd receive nutrition from the digested food.Both humans and the bacteria benefit. Otters & Kelp: the otters help the kelp by eating the sea urchins which endanger it. The kelp provides an anchor for the otters while they sleep. Lichens is really 2 organisms: algae & fungus •
The fungus needs food but cannot make it. The algae makes food but needs some way to keep moist. The fungus forms a crust around the algae which holds in moisture. Both organisms benefit.
Cleaner fish & Moray Eel •
The cleaner fish eats parasites and food bits out of the inside of this moray eel. It gets a meal and is protected from predators by the fierce eel.
3. Parasitism: One organism benefits, the organism is harmed Bedbugs: •
Bedbugs are small, nocturnal parasites that come out of hiding at night to feed on unsuspecting humans. They feed exclusively on blood! Their bites often result in an allergic reaction.
Tapeworms: •
The definitive host of the cucumber tapeworm is a dog or a cat (occasionally a human). Fleas and lice are the intermediate host. the dog or cat becomes contaminated when the eggs are passed in the feces, and the flea or louse ingests the eggs. The dog or cat (or human) is infected when they ingest a flea or louse. Hence the importance of controlling fleas on your pet! Presence of parasites in an animal results in the inability of the host to maintain homeostasis.
Athlete’s foot: The fungus that causes athlete's foot is calledTrichophyton, and is commonly found on floors and in clothing. Athlete's foot is a form of ringworm. Athlete's foot typically develops between our toes and occasionally on other parts of our feet. It usually causes burning, stinging and/or itching. It is the most common type of fungal infection. Although it is contagious, athlete's foot is usually easily treated with OTC (over-the-counter, no prescription required) medication.
Habitat: The place where an organism lives
Examples: • •
•
A fish lives in a pond, Bacteria that live in the human digestive tract, An earthworm lives in the soil Niche-‐ the specific role played by an organism in it’s ecosystem. If 2 organisms occupy the same niche (environmental requirements) they will compete against each other for food, nesting sites, limited resources…. Examples: Consumer, Producer , Decomposer, Predator
• • •
Only one species at a time can occupy a particular niche If there is more that one species there will be competition It may appear that more than one species occupies a niche Ex-‐ Darwin’s Finches – but some may eat small seeds and others large seeds
The shelf fungus absorbs materials from the tree, while the slug eats algae growing on the outside of the trunk. They do not compete with each other for food because they occupy the same habitat but different niches.
The shelf fungus absorbs materials from the tree, while the slug eats algae growing on the outside of the trunk Feeding Relationships
• • • •
Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers) and finally to decomposers Food Chains are a series of steps in which organisms transfer energy by eating or being eaten. Food webs show the complex interactions within an ecosystem. (many food chains linked together) Each step in a food chain or web is called a trophic level. Producers make up the first step, consumers make up the higher levels.
Food Chain •
A food chain indicates the transfer of energy from producers through a series of organisms (consumers) which feed upon each other.
Aquatic Food Chain: minerals enter the water from the surrounding soil by diffusion.
Producer – all autotrophs in a community
•
• •
Organisms that make their own food using energy from the sun and inorganic raw material Primary consumers: organisms that eat producers Herbivores-‐ organisms that eat only plants or plant parts Secondary consumer-‐ organism that eat primary consumers Third order consumer – organisms that eat secondary consumers Fourth order consumer – organisms that eat third order consumers
food web is a series of interrelated food chains which provides a more accurate picture of the feeding relationships in an ecosystem, as more than one thing will usually eat a particular species. Includes alternative pathways for energy flow
There are usually 2 things that are missing from food web diagrams but are absolutely necessary. SUN: source of energy Decomposers: Convert large molecules into simpler molecules that can be recycled Bacteria or fungi that feed off of dead matter (consume) & organic wastes and recycle the minerals to the soil, making the soil rich. • They put nutrients back into the soil & releases Nitrogen gas when tissues od dead plants & animals are broken down.
An ecosystem can’t sustain itself if there are more consumers than producers (photosynthetic)
A Self-‐Sustaining Ecosystem MUST HAVE: 1. Materials are recycled. 2. A constant input of energy.
Ecological Pyramids
•
An ecological pyramid is a diagram that shows the relationship amounts of energy or matter contained within each trophic level in a food web or food chain. It shows loss of energy from different organisms
• • Energy Pyramid : primary source of energy for all organisms is the sun
Only 10% of the energy available within one trophic level is transferred to organisms at the next trophic level.
Most energy in a food web is at the producer(autotroph) level and decreases at each feeding level Each level becomes smaller because the organisms use energy to carry out life functions and some is released as heat
•
ENERGY CAN NEVER BE RECYCLED!!
Most energy is in the bottom layers (autotrophs/producers), least energy is at the top (heterotrophs/consumers). Energy is lost as heat
Biomass Pyramid
• • •
Biomass pyramids show the total amount of living tissue (mass) available at each trophic level. This shows the amount of tissue available for the next trophic level. The producer level contains the largest biomass and it decreases at each level as a result of energy being lost from as it flows from producers to carnivores.
Cycles of matter(material) : Water, Oxygen, CO2 are recycled and Energy is not recycled. • • • • •
In a self sustaining ecosystem materials must be recycled between organisms and the abiotic environment Unlike the one-‐way flow of energy, matter is recycled within and between ecosystems. These cycles are the water cycle, Nutrient Cycle, Carbon Cycle, nitrogen cycle and phosphorus cycle. Energy is not recycled, its lost as heat or waste, it is used by an organism to survive, it is obtained through consumption of food.
Carbon-‐ Oxygen Cycle: Cutting down the rainforest or trees causes an increase in CO2 & and a
decrease of oxygen (O2) in the atmosphere •
These elements are recycled by the processes of: Respiration (uses O2 and produces CO2) Photosynthesis (uses CO2 and produces O2) Both processes involve O2, CO2 & H2O
Water Cycle Water Cycle - The cycle starts when the sun's heat evaporates water from the oceans into the atmosphere to form clouds. When the conditions are just right, the clouds release water as rain or
snow. Most of the rain falls in the oceans, but the rest falls onto land. Rivers and streams collect water from the ground and return it to the ocean so the whole cycle can start all over again. The water cycle never ends because the salty ocean water constantly supplies fresh water to the continents. Water is recycled by the processes of: • • • • • •
• • • • •
Photosynthesis Respiration Transpiration: water(vapor) loss from plants & trees into the atmosphere Evaporation: liquid water ( oceans, lakes, puddles…) turns into water vapor & enters atmosphere Condensation: formation of clouds Excretion: Animals & humans lose water
Nitrogen Cycle
Nitrates: are used by green plants to synthesize proteins Decomposers: convert nitrogenous wastes to ammonia Nitrifying bacteria: convert ammonia to nitrates Denitrifying bacteria: break down nitrates into free nitrogen which enters the atmosphere Nitrogen fixing bacteria: convert free nitrogen into nitrates to be used by plants Legumes – peas, bans and clover – have nodules of where bacteria live (mutualism)
Animals obtain nitrogen by eating plants or eating animals that ate plants
Succession: major factor determining the final stage in succession is the climate of the area
The replacement of one community by another until a stable or climax community is formed Each community causes changes in the environment that allows other communities to replace them Changes in a community over time. All ecosystems go through succession Two types of Succession. Primary Succession Secondary Succession
• • • • • • • •
Primary Succession • • • • •
Bare Rock is broken down by lichens and mosses to make soil Weeds and grasses begin to grown in the small amount of soil . . . They add to the organic matter as they die and are broken down by bacteria Bushes and shrubs begin to grow as the soil deepens The first trees are Pines and Hickories This eventually grows into a mature forest or climax community Flowing lava is so hot it destroys everything in its path, but when it cools it forms new land.
Secondary Succession • • •
Occurs after a community has been cleared because of a disturbance. (natural or artificial) Examples of possible disturbance include: fire, deforestation by humans, hurricanes, and earthquakes Secondary succession is usually much quicker than primary succession for the following reasons: – There is already an existing seed bank of suitable plants in the soil. – Root systems undisturbed in the soil, stumps and other plant parts from previously existing plants can rapidly regenerate. – The fertility and structure of the soil has also already been substantially modified by previous organisms to make it more suitable for growth and colonization.
Secondary Succession -‐ occurs after human intervention or a natural disaster
Secondary Succession takes less time to reach a climax community since pioneer species are not involved Pioneer Organisms • The first plants to populate an area
Examples: Lichens on bare rocks
Pioneer Organism: First organism.
=Always a producer. • •
Usually lichens, moss, algae or grass. Lichens turn solid rocks into soil.
Then come: Small plants, Shrubs, Pines & Other trees •
Flora
•
Fauna
plants animals
Succession in New York •
Grass-‐ Shrubs-‐ Conifer-‐Deciduous Woodlands
• •
Flora succession is the major limiting factor for fauna succession A limiting factor is any factor that limits the size of a population
Climax Community • • •
A relatively diverse and stable ecosystem that is the end result of succession They are named after the dominant plant species They will persist until major catastrophic change alters or destroys the community
(fire, volcanic eruptions etc)
If disaster strikes… •
The SAME ecosystem will be reestablished after several years.
Maintaining a Stable Ecosystem: sexual reproductiongenetic variationbiodiversityecosystem stability Ecosystems tend to show cyclic changes around a point of equilibrium ( a state of balance between opposites)
Checks and balances
• • •
As a population increases it is held in check by one or more environmental factors or by another species (example predator –prey) An example of equilibrium : nutrients from decayed organisms being recycled in a forest ecosystem.
Carrying capacity – the size of a population that can be supported by an environment. Population of an organism will remain constant when it reaches the carrying capacity, then it will alternately increase & decrease. Carrying capacity has been met
• • • •
Population – a group of individuals of a single species that occupies the same general area. Exponential growth model – the rate of expansion of a population under ideal conditions Population-‐limiting factors – hunting, amount of space suitable for breeding, restricted population growth, food availability Logistic growth model – idealized population growth slowed by limiting factors as the population size increases
Limiting Factors • • •
Factors in the environment that limits the size of the population Abiotic factors : sunlight, water, oxygen, nitrogen, pH, ,shelter, disease, temperature, climate change, amount of nutrients in the soil(fields planted with same crop every year) Biotic factors: predators/prey, food
Competition • •
•
Occurs when organisms of the same habitat compete for limited biotic and abiotic resources May occur between organisms of the same species May occur between organisms of different species
***disruptions in the number and type of species, environmental changes and man made changes can upset the balance of the ecosystem Predator-‐Prey relationships
Competition
Wolf
Hawk
BIODIVERSITY • The variety of different species in an ecosystem or in the world
Rainforests: Chemical in rare plants may lead to life saving medicines • • • •
More than 50% of the world's plant and animal species inhabit the 7% of the world that is covered in rainforest. Two to three football fields of rainforest are cut down(cleared) every day, decreasing biodiversity. An estimated 450 species are going extinct every day. Decreasing biodiversity could cause a loss of future foods or medications.
High biodiversity means a greater variety of genetic material.
Evolutionary changes have resulted in a greater diversity of organisms and their roles in the ecosystem. •
Biodiversity increases the stability of an ecosystem
Biodiversity = Stability • •
Biodiversity provides a variety of genetic material that may lead to beneficial agricultural or medical uses Biodiversity increases the chances that some species will survive large environmental changes.
Biomes Energy Transfer • • •
The sun heats the earth unequally, causing differences in temperature. Evaporation and precipitation of water occurs because of the unequal heating. .
Latitude North pole 90 N Low sunlight
sunlight
Arctic Circle 66.5 N
Tropic of Cancer 23.5 N Equator 0 degrees
Most direct sunlight
Tropic of Capricorn 23.5 S sunlight
Antarctic circle 66.5 S Low sunlight
South Pole 90 S
The amount of direct light can affect the temperature.
• •
Remember that the equator gets the most sunlight, and polar regions gets the least. An increase in altitude has the same effect on the habitat of an organism as an increase in latitude.
Precipitation • • • •
The amount of water falling in the given area can greatly affect the type of climate Remember that precipitation falls at 0° and 60 Because of these two factors combined, we get specific biomes at specific areas. Sunlight and precipitation affect the climate
• Climate over an environment produces a biome • A biome has organisms suited to the climate • Biomes generally occur on the same latitudes There are two main types of biomes Land & Aquatic (water) Most land biomes are named after their climax community (type of climax vegetation). From arctic circle(66.5 degrees N) to the equator (0 degrees): tundrataigatemperate foresttropical forest
Some of the land biomes – – – – – – –
Tundra Taiga (TIGH-‐guh) Temperate deciduous forest Grassland Tropical rain forest Desert Tropical rain forest
Biomes: Characterized by their climate. Defined by the plants & animals that live there. Rain Forest-‐> heavy rainfall, broad-‐leaved plants, hot temperature, near equator, ferns, vines, dwarf palms, sloths. Monkeys, tree frogs Deciduous Forest deciduous(leaves change color) hardwood trees, moderate precipitation. Eastern North America & Europe, deer, bears , rabbits, blue-‐jays, cold winters & warm summers Grassland-‐>central U.S., moderate precipitation, oats, rye, wheat, bison, prairie dogs, foxes,antelope Taiga-‐> cold winters, coniferous trees (cone bearing), much snow, Canada & Northern Europe. Fir, hemlock, spruce trees, caribou, lynx, snowshoe hare, moose , elk, bears, wolves Desert-‐> hot days, cool nights, little precipitation, succulent plants (cactus), Southwestern U.S., Northern Africa, Mid East. tortoise, snakes, lizards Tundra-‐> long, cold winters, frozen subsoil. No trees, Northern Canada & Asia, cushion plants, grasses, moss, , snowy owls, caribou, mice Marine-‐> Oceans-‐saltwater, most of the planet, sharks, whales, coral, kelp, seaweed, plankton Freshwater-‐> Lakes, ponds, streams, rivers, algae, cattails, crayfish, bass, insect larva
Renewable Resources Renewable energy is a natural choice. Harnessing the earth's own inexhaustible energy -‐ whether from the sun, wind, fuel cells, or other renewable sources -‐ can reduce dependence on fossil fuels and provide clean, affordable electricity
WHY WE SHOULD CARE ABOUT RENEWABLE ENERGY? •
Choosing renewable power provides many benefits: Making use of secure, indigenous, and sustainable natural resources. Helping to keep our air clean. Potential to reduce the production of carbon dioxide -‐-‐ a leading contributor to global climate change. Helping to create jobs for American workers. Establishing the United States as a world leader and exporter of renewable power technologies. Nationwide, reducing dependence on imported oil. By purchasing electricity generated from renewable resources or installing a renewable energy system on your home, you can demonstrate your commitment to a healthy environment and a healthy economy.
BIOMASS ELECTRICITY • • • • •
Biomass consists of organic residues from plants and animals that are obtained primarily from harvesting and processing of agricultural and forestry crops. These are used as fuels in direct combustion power plants. The biomass is burned, producing heat that is used to create steam to turn turbines to produce electricity. The steam can often be used for another process -‐-‐ such as drying vegetables or using in a factory. This is called cogeneration. Examples: forest slash, urban wood waste, lumber waste, agricultural wastes, etc. The components of biomass include cellulose, hemicelluloses, lignin, lipids, proteins, simple sugars, starches, water, hydrocarbons, ash and other compounds.
FUEL CELLS FOR ELECTRICITY Unlike conventional technologies, fuel is not "burned" but is combined in a chemical process. A fuel cell consists of two electrodes sandwiched around an electrolyte. Oxygen passes over one electrode and hydrogen over the other, generating electricity, water, and heat. • Hydrogen fuel is fed into the "anode" of the fuel cell. Oxygen (or air) enters the fuel cell through the cathode. Encouraged by a catalyst, the hydrogen atom splits into a proton and an electron, which take different paths to the cathode. The proton passes through the electrolyte. The electrons create a separate current that can be utilized before they return to the cathode, to be reunited with the hydrogen and oxygen in a molecule of water. • "fuel reformer" can obtain hydrogen from any hydrocarbon fuel -‐ from natural gas, methanol, and even gasoline. Other possible fuels include propane, hydrogen, anaerobic digester gas from wastewater treatment facilities, and landfill gas. Fuel cells are being designed for use in stationary electric power plants to provide reliable, clean, high quality electricity for distributed power generation. Eventually, smaller fuel cells will be sold for use in homes, most of which will connect to natural gas supplies • •
GEOTHERMAL ENERGY • •
Geothermal energy is produced by the heat of the earth and is often associated with volcanic and seismically active regions. California has 25 known geothermal resource areas, 14 of which have underground water temperatures of 300 degrees Fahrenheit (149 degrees Celsius) or greater. Hot water and, in some instances, steam can be used to make electricity in large power plants. Hot water can also be put to direct use, such as heating greenhouses or other buildings. The constant temperature below ground can also be tapped to warm and cool your home through a ground-‐source heat pump.
HYDROELECTRIC POWER •
Hydroelectric power, a renewable resource, is generated when hydraulic turbines are turned by the force of moving water as it flows through a turbine. The water typically flows from a higher to a lower elevation. These turbines are connected to electrical generators, which produce the power. The efficiency of such systems can be close to 90 percent.
SOLAR PV SYSTEMS • • •
We call modern-‐day devices that convert sunlight into energy photovoltaic cells, or "PVs" for short. More commonly, they're known as solar cells. We can find them on calculators, hats, sidewalk lighting systems, and alongside freeways to power phones for stranded motorists.
SOLAR THERMAL ELECTRICITY • •
The sun's heat can be used in two ways with homes and businesses. The sun is used to heat water for domestic hot water systems, or the sun's light can be concentrated and water temperatures increased to make steam and electricity. Solar energy can also generate electricity. Over the past 20 years, solar electricity generation technologies have grown by leaps and bounds, registering annual growth rates between 25 and 41 percent. Costs have also fallen by 80 percent.
WIND POWER: Renewable, does minimal damage to atmosphere, reduces dependency on fossils fuels which cause air pollution • •
•
Wind speeds typically must be sustained and at least 10 miles per hour to turn larger turbines fast enough to generate electricity. The turbines usually produce about 50 to 300 kilowatts of electricity each. A kilowatt is 1,000 watts (kilo means 1,000). You can light ten 100 watt light bulbs with 1,000 watts. So, a 300 kilowatt (300,000 watts) wind turbine could light up 3,000 light bulbs that use 100 watts.
Global Environmental Issues The environment encompasses the whole of life on earth and the complex interactions that link the living world with the physical world. In a general sense, this covers everything contained within the air, land and water. Sudden and dramatic natural changes to the environment have occurred, and continue to occur, which have the potential to upset the whole balance of the Earth's ecosystem. Significant environmental issues cause impacts throughout the world.
Environmental Change • • •
Sudden and dramatic natural changes to the environment have occurred in the distant past, but only relatively recently has one species had the potential to upset the whole balance of the Earth's ecosystem The global population has risen dramatically during the last century The rise of industry and its rapid expansion has been a major source of pollution. This has caused changes in the balanceof our environment
Global Warming: Forests being cut down causes a negative effect on global warming(Increase of CO2) Greenhouse gases (CO2, methane, water vapor) help to maintain the earth’s temperature at a level suitable to support life • Human activities are increasing the amount of greenhouse gases in the atmosphere, which cause more heat to be trapped Predicted effects of global warming include: •
• • • •
Higher sea levels ( will flood coastal areas) Higher temperatures Variable climatic conditions These changes are expected to cause a significant impact on agriculture and ecosystems
Greenhouse Gas Pie
Ozone Layer Depletion • • •
The ozone layer protects the earth from harmful ultraviolet (UV) light The use of chlorofluorocarbons (CFCs) and other ozone depleating substances as refrigerants, solvents and insulation is destroying the ozone layer A ‘hole’ is observed over Antarctica every autumn Depleated ozone levels cause the following impacts: – Increased penetration of UV light to earth – Increased risks of skin cancer and eye diseases – Damage to agricultural crops – Disruption to marine food chains
Acid Rain: Due to air pollution •
• •
The burning of fossil fuels( coal, oil) leads to atmospheric emissions of NO and SO x
2
These gases react with water and oxygen to make sulfuric and nitric acids. Sunlight increases the rate of these reactions Rain, snow and fog can be polluted with these acidic compounds, which is then deposited at the earths surface The deposition of acids can: – Damage forests and soils – Causes acidification of lakes and other water bodies (lowers the pH) causing fish & other aquatic life to decrease – Disturb wildlife – Cause the decay of building and other structures – Impact on human health
Deforestation • • • •
The deforestation of tropical rainforests is a major global problem-‐each year millions of hectares are lost Deforestation rates in some countries continue to increase despite worldwide pressures Rainforests are destroyed for wood products, and to make way for agricultural activities, mining and dams The impacts of deforestation include: – Loss of livelihood for local inhabitants – Variable environmental conditions (susceptability to flood, aggravated droughts, soil erosion etc) – Loss of biodiversity and disturbance to ecosystems
Loss of Biodiversity •
• • • •
Biodiversity has three key components: – Genetic diversity – Species diversity – Ecological diversity Approximately 2.1 million species are known to exist, but up to 50 million still to be discovered Biodiversity is important for food, drugs, maintaining ecological stability, aesthetic and cultural benefits Natural causes and human activity can threaten biodiversity The loss of biodiversity means ecosystems are destabilized, vital resources are lost and genetic variation is reduced
Water Pollution • •
A change in water quality that impacts on living organisms Types and effects of water pollution include: – Infectious agents, such as typhoid, cholera – Nutrients and eutrophication – Toxic materials, through mining & factories (PCB’s) causing fish unfit to eat – Organic chemicals such as fertilizers for the lawn – Sediments can disrupt aquatic ecosystems
Air Pollution: Caused by factories(industry) putting chemicals into the air, & cars putting chemicals into the air(exhaust) Quality of air can be improved if we buy cars that get more miles per gallon of gasoline ( non-‐ renewable), or we use alternate fuel such as ethanol (renewable) instead of gasoline.
Waste Disposal •
•
•
Waste disposal methods include: – Open dumping and landfill – Ocean dumping – Exporting waste – Waste to energy plants Minimizing the waste stream: – 3R’s: reduce, reuse, recycle – Composting – Waste to energy Hazardous waste disposal – Needs to be safely handled and disposed of to minimize threats to the environment and human health
Environmental Management • • • •
Environmental pollution is a serious burden on our ecosystems and finances world-‐wide Administrations, commercial organizations and individuals are affected by environmental change and its associated dangers, long-‐term effects and liabilities Both legislative obligations and voluntary mechanisms can address the environment and to integrate it into the mainstream of business activity Consequently, environmental management is a crucial part of all organizations’ operations