Transcript bioproject
Human Body Systems A.P. Bio Project Yuru Zhang, Per. 4 Table of Contents Digestive System, Slides 3-13 Reproductive System, Slides 95-107 Circulatory System, Slides 14-26 Nervous System, Slides 108-118 Respiratory System, Slides 27-35 Endocrine System, Slides 119-125 Excretory System, Slides 36-46 Immune System, Slides 47-58 Muscular System, Slides 59-72 Skeletal System, Slides 73-85 Senses System, Slides 86-94 Digestive System Function The function of the digestive system is to break down food into small molecules our body can use to build cells, provide energy, and to dispose of waste products. Organ Functions Mouth: the salivary glands release fluids to form saliva, which breaks down food & kills germs Esophagus: Muscle contractions (peristalsis) channel food to stomach Stomach: stores food that is being broken down with acid & enzymes Small intestine: bile from liver & pancreas enzymes break down food molecules, absorbs nutrients into bloodstream Organ Functions Pancreas: secretes digestive enzymes (breaks down protein, fats, carbs), makes insulin, metabolizes sugar Liver: produces bile, digests fat, breaks down toxins, processes nutrients from small intestines Gallbladder: stores & concentrates bile Large intestine (colon): Processes digestive waste, makes it easier for waste to be emptied out Rectum: connects lg. intestine to anus, sends signals to brain when waste leaves colon about to exit body Anus: sphincter muscles control excretion of liquid, solid, or gaseous waste Other parts The cecum is the beginning of the ascending lg. intestine, and it collects all the waste from the sm. intestine. The plyoric sphincter allows food to pass from the stomach to the duodenum of the small intestine. The cardiac orifice is a opening past the diaphragm, which allows the esophagus to communicate with the stomach. The appendix is the small pouch at the end of the lg. intestine that has to practical use. It sometimes builds up waste, which can lead to a painful swelling, a.k.a. appendicitis. Accessory organs make the digestive chemicals (enzymes, saliva, bile) that digest, break down food Alimentary organs absorb nutrients from the digested food, and they form the digestive tract. Digestion & Role of Enzymes Large molecules have to be digested, since small intestines can only absorb small molecules with facilitated diffusion or active transport. Large molecules won’t fit. Some compounds have to be broken down, then reassembled in order for our digestive system to digest them. Enzymes are used to break down food, toxins, and many other compounds involved in digestion. Phys. vs. Chem. Digestion Physical digestion, like the name, involves the mechanical breaking-down of food. The teeth are extremely useful in grinding up food into smaller particles. Also, the stomach churns the food up, which effectively smashes and condenses the food pieces up together. Chemical digestion involves saliva, digestive enzymes, stomach acid, and bile. They all break down food into smaller molecules through chemical processes, such as hydrolysis. Carb & Protein digestion Carbohydrates are hydrolyzed in the stomach and upper small intestine to form monosaccharides, which can be absorbed by the small intestine. Carbohydrates are digested by salivary amylase, maltase, sucrase, and lactase. Proteins are mainly digested by enzymes. These include proteases, pepsin, trypsin, etc. Amount of protein, concentration of acid are factors to how the proteins are broken down. Proteins are digested in the stomach and upper small intestine. Disorders Acute pancreatitis, which is a inflammation of the pancreas. Symptoms include chills, abdominal pain, weakness, & weight loss. More common in men than women. It’s caused by enzymes that digest pancreas tissue, causing the pancreas to bleed and swell up. Cause could be genetic, alcoholism, or unknown. It can be treated with ERCP or by simply avoiding alcohol and fats. Also, painkillers may help ease the symptoms. Crohn’s disease is an inflammation of the digestive system, from the mouth to the anus. Abdominal pain and diarrhea are common symptoms. It occurs in both sexes and runs in families. It usually begins in young people between 13 to 30 years of age. Smoking may increase risk of disease. People of Jewish ancestry also have a higher risk. It can be treated with surgery and/or antibiotics. Digestive System Sources A.P. Bio textbook http://www.tpub.com/corpsman/49.htm http://faculty.clintoncc.suny.edu/faculty/michael.gregory /files/bio%20102/bio%20102%20lectures/digestive%20 system/digestive%20system.htm http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH00013 32/ http://www.nlm.nih.gov/medlineplus/crohnsdisease.htm l Circulatory System Function The purpose of the circulatory system is to transport blood, oxygen, and carbon dioxide to and from the lungs. Also, the system transports nutrients to cells and waste away. Oxygen goes from the lungs to the cells and travels through the bloodstream throughout the body. Carbon dioxide travels to the lungs to be released. Structure & Functions Arteries, blood vessels that transport blood from the heart throughout the body. It’s made up of elastic fibers and connective tissue to make it able to withstand the pressure of blood flow. Veins, blood vessels that carry deoxygenated blood back to the heart, except pulmonary vein, which carries oxygenated blood to the heart. They have valves that prevent blood from flowing back. They are located nearer to the skin and are more visible than arteries. Veins have a structure much like arteries, allowing them to transfer large volumes of blood, without bursting. Capillaries, small blood vessels that form a bed winding throughout muscle. This structure allows them to move substances, such as oxygen and carbon dioxide in and out. Also, their small size enables them to quickly and efficiently transport erythrocytes to various sites in the body. Blood Routes in Heart Blood enters the heart from the vena cava, which transfers deoxygenated blood to the right atrium. Then, the atrium pumps the blood into the right ventricle (past the AV valve), up through the pulmonary artery (past the semilunar valve) to the lungs. The blood is oxygenated there, and then, the blood reenters the heart from the pulmonary vein. The blood is now in the left atrium, which pumps it through the AV valve into the left ventricle. From there, the blood goes past the semilunar valve up into the aorta, which pumps blood throughout the body. Both valves depend on the pressure of the arteries and veins. When the arteries have more pressure than the veins, the AV valves open and the semilunar valves close. When the veins have more pressure, the AV valves are shut and the semilunar valves open. Composition of Blood Plasma, a great portion of blood, liquid, mostly water. It contains nutrients like glucose and fatty acids that are transported throughout the body. Also, it removes waste products, like urea and carbon dioxide. Plasma is useful for blood-clotting, carrying antibodies, proteins, and electrolytes. Erythrocytes, red blood cells, delivers oxygen throughout the body using the blood flow and the circulatory system. It’s reddish color is from the large amounts of iron in the hemoglobin (oxygen binds to this molecule). Leukocytes & Platelets Leukocytes • consist of lymphocytes and monocytes • B lymphocytes, make antibodies • T lymphocytes, use macrophages, kill virus-infected cells, help production of antibodies • Monocytes, become macrophages that “eat” antigens and dead cells Platelets • Sticky substances that help clot bloods to prevent excessive bleeding. • Forms with exposure to air, forms clot, dries and hardens to a scab Erythrocytes Depressed center Oxygen diffusion in lungs Small and a flexible structure Able to squeeze through tight capillaries Open and Closed Systems Closed Circulatory • Mostly vertebrates and a few invertebrates • Blood is only in the blood vessels, doesn’t go to body cavities • Humans have a closed circulatory system. Open Circulatory • • • • Arthropods and mollusks Blood doesn’t travel with blood vessels Fills body cavities Surrounds tissues with blood, diffuses cell to cell through the circulatory system • Crayfish are an example. Circulation Variations Fish Gills, ventilation, current of water flowing over the respiratory surface Countercurrent exchange, allows oxygen to be transferred to the blood Amphibian Positive pressure breathing, oral cavity rising forces air down trachea Elastic recoil of lungs forces air out of lungs Mammals Negative pressure breathing, air is pulled into the lungs, diaphragm contracts to increase lung volume Surface tension allows movement of lungs to also move the rib cage. Birds use parabronchi to exchange gases, one direction air flow, no alveoli. More complex ventilation. Birds can breathe better at higher altitudes. Circulation Variations Reptile Three-chambered heart, similar to amphibians. Two atria, ventricles are undivided (mixing of deoxygenated and oxygenated blood may occur) Circulations is divided into three channels: pulmonary trunk, right and left systemic trunks Atherosclerosis Atherosclerosis is a disease of the arteries that can lead to heart attack, stroke, and death. Occurs when plaque hardens, blocking arteries (blood flow is limited) People with high bad cholesterol levels and high blood pressure are at risk (unhealthy diets, lack of physical activity also up the risk) Symptoms: sudden weakness, dizziness, breathing problems, trouble hearing or seeing Treatment: medication to decrease plaque buildup, can prevent blood-clotting, medical procedures done on blocked arteries, healthy lifestyle habits can prevent this disease Raynaud’s Disease Raynaud’s disease is a disorder of the arteries. Causes blood vessels to narrow, reducing blood flow Cause: unknown (other diseases and conditions can be triggers), cold temperatures and stress are also triggers Symptoms: Affected body part will turn white and blue, skin will tingle and burn Five percent of people in U.S. have this disease. Treatment: no cure, medicine and/or surgery may temporarily relieve symptoms, easily prevented by avoiding triggers Circulatory System Sources http://www.biosbcc.net/b100cardio/htm/heartant.htm http://www.unm.edu/~mpachman/Blood/platcomp.htm http://jamespendleton.suite101.com/erythrocyte-life-cyclefunctions-and-pathology-a84625 http://www2.gsu.edu/~bioasx/closeopen.html AP Bio book, pgs. 884-889 http://www.shsu.edu/~bio_mlt/Chapter12.html http://health.nih.gov/topic/CirculatoryDisorders Respiratory System Function The function of the respiratory system is to supply oxygen to the blood and to expel carbon dioxide from the body. It does this by breathing in air (inhaling oxygen, exhaling carbon dioxide). Alveoli Features They are the body’s primary gas exchange units. Located in the lungs. Shaped like interlinking sacs Thin, fluid-lined walls allow gases to dissolve Capillaries surround them, so oxygen can enter bloodstream (diffusion) Large surface area, smaller volume Transport of Carbon Dioxide & Oxygen Carbon dioxide is transported by red blood cells. Carbon dioxide is dissolved in the plasma (bound to the hemoglobin) Oxygen is also bound to the hemoglobin (at a different site) and is carried around by the red blood cells. Path of Oxygen Enters mouth and/or nose. Passes through trachea (windpipe) Enters bronchi, then to bronchioles Reaches alveoli, where the oxygen is in close contact with the bloodstream. Diffuses across and is bound to the hemoglobin in RBC’s Oxygen reaches the heart and spreads throughout body with circulatory system. Inhalation & Exhalation Inhalation • Diaphragm contracts • Intrapleural space expands • Pressure decreases, lung volume increases • Air flows in Exhalation • • • • • Diaphragm relaxes Rises up Pressure on lungs increases Lung volume decreases Air is expelled Chronic Obstructive Pulmonary Disease Lung disease that makes it hard to breathe Symptoms: cough, fatigue, respiratory infection, wheezing, shortness of breath Causes: smoking, gaseous fumes, secondhand smoke, pollution Prevalence: third leading cause of deaths in U.S., more females than males, around 16 million people in U.S. with COPD Treatments: quitting smoking, inhaler usage, anti-inflammatory medicine, antibiotics, avoiding cold air and smoking, stay away from air pollution sources, surgery Pneumonia It’s an infection of the lung, and affects breathing. Causes: bacteria and viruses that infect the nose or mouth spread to the lungs, direct infection of lungs, or inhalation of foreign substances into the lungs Smoking, Cerebral palsy, lung disease, immune system problems are just some of the factors that increase the risk of getting pneumonia Symptoms: cough, fever, chills, shortness of breath, headache, fatigue 3 million pneumonia patients each year, 60,000 die, 1/3 of them are over 65 years old, 4% of children in U.S. are infected Treatments: antibiotics, breathing treatments, drinking plenty of fluids, breathing in warm air Respiratory System Sources http://www.fi.edu/learn/heart/systems/respiration.html http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH00011 53/ http://www.copd-international.com/library/statistics.htm http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH00012 00/ http://www.healthcommunities.com/pneumonia/overvie w-of-pneumonia.shtml A.P. BIO Book E X C R E T O R Y S Y S T E M Function The functions of the excretory system are: Remove solid and liquid waste from body Excretes cell by-products Maintains balanced chemical concentrations Wastes Ammonia Common in aquatic species Readily diffuses from organism’s membranes to surrounding water Needs to be diluted down by large sources of water High concentrations are toxic to organisms Lost as ammonium ions by most fish Soluble in water Wastes Urea Secreted by mammals, sharks, amphibians, bony fishes Produced in liver, combining ammonia with carbon dioxide Low toxicity, requires much less water, less loss of water Useful for organisms living w/o access to sufficient water Requires energy to produce (amphibians could switch between excreting ammonia and urea depending on water resources Soluble in water Wastes Uric acid Reptiles, birds, and insects secrete this Not as toxic as ammonia Insoluble in water Excreted as a paste Little water loss, good for organisms w/o much access to water Takes up a lot of energy to produce this waste Nephron The functions of the nephron are to remove waste and excess substances from the blood and to replenish the body’s sodium, potassium, and phosphorus levels. Nephron Processes Filtration • Body fluid is forced through selectively permeable membranes • water, salt and nitrogenous wastes are sent to excretory system (filtrate) Selective reabsorption • Active transport reabsorbs substances like glucose, salts, and amino acids from filtrate • Toxins and excess salts are left in filtrate Nephron Processes Secretion • Using active transport, toxins and waste are added to filtrate from body fluids • Water, with osmosis, is pushed to the excretion Excretion • Filtrate leaves system and body • In humans, urine is excreted (produced by nephron) • Blood vessels around nephrons are useful in transportation of fluids Interstitial nephritis Kidney disease, inflammation of tubule spaces Symptoms: urine in blood, fever, nausea, vomiting, weight gain Causes: long-term use of medications like Tylenol and aspirin, too much potassium in blood, too much uric acid and calcium Over 39,480 nephritis deaths in U.S. each year Treatment: Less salt and protein in diet, antiinflammatory medication Cystitis Bacterial infection of the bladder Causes: bacteria that enter from the urethra, may spread to kidneys, diabetes, bladder blockage, or pregnancy can increase risk of cystitis Symptoms: cloudy and bloody urine, pain with urination, urge to urinate often even with an empty bladder Prevalence: more women than men, most deaths occurred in Mexico and Brazil, usually not deadly, 15 deaths in U.S. Treatment: antibiotics, drinking plenty of water, medication that reduces pain and urination urge Excretory System Sources AP Bio Book, Chapter 44 http://www.nlm.nih.gov/medlineplus/ency/article/000464.ht m http://www.rightdiagnosis.com/n/nephritis/stats.htm http://www.nlm.nih.gov/medlineplus/ency/article/000526.ht m http://www.nationmaster.com/graph/mor_cys-mortalitycystitis http://www.emc.maricopa.edu/faculty/farabee/biobk/bioboo kexcret.html Immune System Functions Protects body from infection Ingest and destroy pathogens Detects viruses, parasites, etc. and can tell difference between unhealthy and healthy tissue. Major Organs Adenoid, located in back of nasal cavity above roof of mouth, spongy tissue helps protect against infection Tonsils, located on sides of throat, helps fight infections, tonsils may get infected (tonsillitis) Lymph nodes, oval-shaped organs located in various places in body, trap foreign particles, become inflamed or enlarged during infection or cancer Spleen, filters blood, kills infected RBC’s, initiates immune response if foreign particles are found in blood Lymphatic vessels, carry lymph throughout body, foreign particles are accumulated, so macrophages, dendritic cells, and lymphocytes can kill the germs Recognition of Pathogens Lymphocytes recognize foreign particles specifically and causes a immune response. Antigens are foreign proteins or polysaccharides that cause lymphocytes to respond. Antibodies bond to foreign particles to prevent them from entering and damaging cells. They can also trigger immune responses to destroy the foreign particles. Innate & Acquired Immunity Innate Acquired Not antigen-specific • Lymphocytes Skin and mucus are • Cells from red bone physical barriers marrow • Sweat, tears, and • Cells are saliva break down found in bacteria blood and • Neutrophils and lymphatic macrophages use tissue phagocytosis • • • Immunity that develops through exposure to antigens • Antibodies, T and B cells • Can cause allergic reactions • Cells might mature at thymus Active & Passive Immunity Active • • Artificial • antigen-containing substance injected • Immune response is stimulated • antibodies build up • Vaccines Natural • Body encounters live pathogen • Immune system remembers it • Body will react faster to counter the pathogen the next time Passive • Immunity can be passed on from parents • antibodies are transferred from immunoglobulin • Immunity is not developed; it’s already there or given directly Humoral & Cell-mediated Immunity Humoral • Deals with potential infectious • Both store particles in tissue and blood antigen • Uses antibodies info into • Macrophages ingest and memory destroy infectious agents • Both are • Helper-T cells recognize types of infectious agent components, acquired cause immune response immunity • B-Cell Activation Cell-Mediated • Deals with infected cells • Killer-T cells destroy infected cells • Antigen and foreign particle info are stored in memory • Helper T-Cells • Secondary response • Antigens, cytokines from helper T’s activate B cells • Activated cells can be memory B cells or antibody-secreting plasma cells • Degrade bacteria and cause exponential activation of other B cells • Activated by binding to surface proteins on infected cell • Cytokines from helper T cells help activation • Activated T cells kill infected cells by secreting proteins on it T Lymphocytes B Lymphocytes B & T Lymphocytes Antibiotics Antibiotics help kill bacteria by destroying their cell wall, by recognizing and disabling certain chemicals and enzymes that are unique to the bacteria. They may prevent the bacteria from reproducing. Viruses are unaffected by antibiotics, because they only contain a piece of DNA or RNA. Viruses can only reproduce and gather nutrients using their host cells, so they don’t have a metabolism to disrupt with antibiotics. HIV/AIDS Human immunodeficiency virus, a retrovirus, attacks the body’s immune system, preventing the body from effectively fighting infections. Symptoms: No early symptoms, possible headache, fever, enlarged nymph nodes, later on: pneumonia, brain infections, widespread diseases and fungal infections Prevalence: About 40 million people in the world have this disease, 25 million have died, 85% transmitted through heterosexual intercourse, homosexual transmission and intravenous drugs are a large proportion of AIDS diagnosis causes in the U.S. Treatment: medications like Raltegravir, reverse transcriptase inhibiting drugs (zidovudine), antiretroviral drugs and therapy Systemic lupus erythematosus (SLE) An autoimmune disease (immune system attacks healthy tissue), exact causes not known, possibly caused by certain drugs. Can affect almost any body part. Symptoms(depends on part of body affected): Fatigue, fever, hair loss, sunlight sensitivity, skin rashes, coughing up blood Prevalence: Occurs more frequently in women than men, more African Americans and Asians than other races, people > 10, < 50 Treatment: no cure, symptoms can be controlled with NSAIDs, skin creams, or corticosteroids (or any other relieving drug that treats the affected body area), regular screening, immunization, and appointments are recommended Immune System Sources http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH00014 71/ http://www.emedicinehealth.com/hivaids/page6_em.htm #HIV/AIDS%20Treatment AP Bio Book, Chapter 43 http://health.howstuffworks.com/medicine/medication/ question88.htm http://www.biology-online.org/1/11_cell_defense_2.htm Muscular System Function Allows body to move around, locomotion (skeletal muscle) Ability to generate heat Movement by contraction and relaxation of muscles Cardiac muscle in heart pumps blood Smooth muscle in organs, lines digestive tract (helps in digestion) Muscle Types Skeletal Muscle Striated muscle, myofilaments create light and dark band patterns Attached to bones, movement of body Contains repeating units, sarcomeres Bundle of muscle fibers Muscle fibers, bundle of myofibrils Cardiac Muscle Striated muscle, like skeletal Different electrical and membrane properties Ion channels in cell plasma membrane Action potential triggered without immune system Intercalated disks, where the cells interlock Gap junctions, electric coupling between the cells Action potential is spread to all the cells, heart contracts Smooth Muscle Makes up hollow organs, (blood vessels, GI tract, bladder, & uterus) Smooth, no cross striations Smaller in diameter than skeletal muscle fibers Single-unit muscle in dense sheets/bands Multi-unit muscle have no interconnecting bridges, mixed with connective tissue fibers Sarcomere Sliding-Filament Model Thin filaments and thick filaments don’t change length during sarcomere shortening Filaments slide past each other longitudinally Thin and thick filaments overlap I band and H zone shrink (Less thin or thick filament only areas) Myosin and actin interactions Acetylcholine Neurotransmitter biochemicals Carry nerve impulses across synapses (between neurons) Carries impulses to muscle cells through motor plate Generates muscle contractions. Vital to nervous system and muscular system Chemical messenger Important role in memory Calcium ions and Cross-bridges Muscle fibers only contract with motor neuron stimulation Binding sites blocked by tropomyosin regulatory protein Calcium ions bing to regulatory proteins forming troponin complex Exposes myosin binding sites on thin filament Muscles contract and relax, depending on concentration of calcium ions in cytosol Cross-bridges form when myosin heads bind to actin, broken when new ATP molecule binds to myosin head ATP is hydrolyzed to ADP, cross-bridge releases ADP and inorganic phosphate, thin filament slides Actin and Myosin Actin Myosin Make up thin filaments Long tail region and globular head region (tails adhere to tails) Binds to myosin head to form a cross-bridge Make up thick filaments Helps in hydrolysis of ATP Myosin head is center of bioenergetic reactions (binding of ATP, hydrolysis of ATP) Duchenne muscular dystrophy Inherited disorder involving the weakening of the muscles Rapidly-worsening version of muscular dystrophy Symptoms: fatigue, mental retardation, muscle weakness, difficulty walking Causes: Inherited, defective gene for dystrophin Prevalence: More common in males than females, 1 out of 3600 male infants Treatment: No cure, future gene therapy, physical activity (a body in motion will stay in motion), orthopedic appliances Tendinitis Inflammation of a tendon from minor impact on an affected area, can occur at any tendon site Symptoms: Pain and loss of motion at site of tendon and surrounding area Causes: everyday activities (gardening, shoveling, sports, etc.), incorrect posture, medication reactions, stress from arthritis or gout Prevalence: More common in older adults (over 40) Treatment: Rest, icing the area, anti-inflammatory medication, for more serious tendinitis: steroids, physical therapy, surgery Muscular System Sources A.P. Bio Book, Chapter 49 http://img.sparknotes.com/figures/E/eb57ee3c0bbce61d887722fc593100 2b/muscular_system_anterior.jpg http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookmusskel.ht ml http://www.webmd.com/osteoarthritis/guide/arthritis-tendinitis http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001724/ Skeletal System Function Structural support Protection of vital organs Allows for movements, with muscles Stores minerals like calcium and phosphorus Produces red blood cells and white blood cells Can store lipids Movement: Bones Muscles have to contract against bones of some type of skeleton Hydrostatic, exoskeleton, endoskeleton Joints allow for movement flexibility (endoskeleton) Peristalsis, rhythmic waves of muscle contractions (hydrostatic) Movement: Ligaments Provide joint stability in movement Prevent hyper-extension or hyper-flexion Bind bones to other bones and joints Elastic, able to lengthen under tension Movement: Muscles Contract against bones to move Able to convert chemical energy into kinetic energy Myofibrils are part of the contraction process Sliding Filament Model Movement: Tendons Connect muscles to bones Able to withstand tension Similar to ligaments Work together with muscles to create movement More elastic than ligaments Able to function as springs, provide stability during rest Hydrostatic skeleton Main skeleton type in cnidarians, flatworms, nematodes, & annelids Fluid-filled compartments under pressure Movement through the changing of the shape of the compartments Peristalsis, rhythmic waves of muscle contractions (annelids) Cushion internal organs, provide support for terrestrial movement (crawling and burrowing) Exoskeleton Hard outer-covering on surface of animals Shell enlarges as animal grows (outer edge growth) Molluscs, bivalves, arthropods Jointed exoskeleton --- cuticle, non-living coat secreted by epidermis (arthropods) Cuticle is made of chitin Protein matrix combines strength with flexibility Molluscs have a mantle, sheet-like body wall extension Bivalves have hinged shell (muscles attached inside close shell) Endoskeleton Support elements, like bones, are buried in soft tissues of body Echinoderms Ossicles (hard plates beneath skin) Made of calcium carbonate and magnesium carbonate Bound together by protein fibers Chordates Cartilage and bone combination Axial (skull, backbone, rib cage) Appendicular (limbs and pelvic girdles) Bones fused together with ligaments, joints provide flexibility Long Bone Osteoporosis Thinning of bone tissue, bones lose density (occurs over time) Most common bone disease Affects about 20% of all American women over 50 Causes: estrogen drop in women, testosterone drop in men, chronic arthritis, eating disorders, Vitamin D deficiency Symptoms: Bone fractures, pain or tenderness, stooped posture Treatment: Bisphosphonates, Calcitonin, Raloxifene High calcium diets and moderate exercise can prevent osteoporosis Arthritis Inflammation of joints, cartilage breakdown Causes: autoimmune disease, broken bones, infections, “wear and tear” Occurs in both men and women, affects one of five people in U.S. Symptoms: joint pain, swelling, reduced movement of joint, stiffness Treatment: Lifestyle changes (exercise, physical therapy, diet change), medication: biologics, corticosteroids, immunosuppressants, surgery (joint rebuilding or replacement) Skeletal System Sources http://www.sciencephoto.com/image/193550/530wm/F00175 72-The_skeletal_system-SPL.jpg http://en.wikipedia.org/wiki/Tendon http://www.brianmac.co.uk/musmov.htm http://www.spineuniverse.com/anatomy/ligaments http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001400/ http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002223/ A.P. Bio book, Chapter 49.5 Senses System Mechanoreceptors Receive signals of physical deformation from stimuli like pressure, touch, stretch, motion, and sound Sense any type of mechanical energy Mammals require mechanoreceptors to have the sense of touch Embedded in connective tissue, location depends on best stimulus (can be deep in skin or on the surface) Thermoreceptors Respond to heat or cold to regulate body temperature Send signals to body surface and core temperatures Send info to posterior hypothalamus Receptors might be encapsulated, branched dendrites or naked dendrites of sensory neurons Chemoreceptors General receptors (transmit info about solute concentrations in solution) Osmoreceptors (mammalian brain) Water receptors (feet of houseflies) Specific receptors (transmit info to certain kinds of molecules) Receptors for specific molecules Chemoreceptors in male silkworm moth antennae (detect female moth sex pheromones) Photoreceptors Electromagnetic receptors that detect visible light Often located in the eyes Proteins absorb photons, cell membrane potential is changed Photoreceptor cells: rods and cones, photosensitive ganglion cells Rods are sensitive at low light levels, colors cannot be seen Cones are only sensitive to higher light levels (more photons) Pain receptors Also known as nociceptors Class of naked dendrites located in the epidermis Stimulus leads to defensive reactions Different receptors respond to different stimuli (excess heat, pressure, or certain chemicals from damaged or inflamed tissues Histamines and acids are some chemicals that trigger pain Rhodopsin A visual pigment, made up of light absorbing retinal bonded to an opsin protein The sensitivity of rod cells (light detection cells in eyes) is dependent on Rhodopsin Comes from b-carotene (carrots) Bright light causes Rhodopsin to change shape, “bleaching” Cell Signaling Signal transduction pathway, signal on cell’s surface is turned into a cellular response Reception Cell detects signal molecule from outside Detection results in molecule binding to a receptor protein located on cell surface or inside Transduction Receptor protein is changed during binding May require a series of steps and different molecules (signal transduction pathway) Response Transduced signal triggers cellular response Any imaginable cellular activity (catalysis, cytoskeleton rearrangement, gene activation) Senses System Sources A.P. Bio Book, Chapters 11 and 49 http://www.nku.edu/~issues/illusions/Photorecepters.ht m http://science.howstuffworks.com/environmental/life/h uman-biology/eye2.htm Reproductive System & Development The function of the system is to ensure the survival of a species through the procreation of offspring. Spermatogenesis --the production of mature sperm cells Sexual vs. Asexual Sexual • • • • Haploid gametes are fused Zygote is formed Meiosis occurs Genetic variability is greater • Greater reproductive success when environment changes quickly Asexual • All genes come from one parent • Fission • Budding • Fragmentation and regeneration • Common in invertebrates • Relies on mitotic cell division Oogenesis Oogenesis is the development of mature ova or eggs. Cytokinesis is unequal. Of the four gametes produced, one is a large daughter cell, which is able to become the ovum. The other three are smaller cells, polar bodies that eventually degenerate. Menstrual vs. Estrous Cycle Menstrual • Humans, other primates • Endometrium is shed • from uterus through cervix and vagina • Behavior changes are not as pronounced • Receptive to sexual activity throughout cycle Estrous • Mammals other than primates Ovulation occurs when • Endometrium is endometrium has reabsorbed by the thickened and a rich blood uterus supply has been • Change in behaviors developed. during cycles • Estrus or heat is the only time mating can occur Hormonal Control Principal male sex hormones are androgens Testosterone Produced by Leydig cells in testes, located near the seminiferous tubules Male reproductive system is directly affected by the hormones Primary (development of vasa deferentia) and secondary (voice deepening, facial and pubic hair) sex characteristics Feedback Mechanism Negative feedback on the hypothalamus and anterior pituitary regulates blood levels of luteinizing hormones, follicle-stimulating hormones, and gonadotropin-releasing hormones Leydig cells produce testosterone & other androgens, that stimulate sperm production and affect the primary and secondary sex characteristics Each hormone acts only on cells with the specific receptors for it Cleavage After completion of fertilization, the cell divides rapidly (cleavage) Cells undergo DNA synthesis and mitosis phases of cell cycle, skipping G1 and G2 (little or no protein synthesis) Zygote is split into small cells called blastomeres First divisions form cluster of cells known as morula Fluid-filled cavity (blastocoel) forms within morula Blastula (hollow ball of cells surrounding large blastocoel) Animals other than mammals have polar eggs and zygotes Cleavage of eggs in frogs and other animals depends on the distribution of yolk in the egg Gastrulation Morphogenetic process that rearranges blastula cells to form a three-layered embryo (gastrula) Same general mechanisms in all species: changes in cell motility, cell shape, and cellular adhesion to other cells/molecules Embryonic germ layers: ectoderm (outer layer), endoderm (inner layer lining the digestive tract), and mesoderm (fills space between ectoderm and endoderm) Ectoderm develops into: epidermis, sensory receptors, cornea and lens of eye, nervous system, tooth enamel, epithelial linings mouth and anus, etc. Mesoderm develops into: notochord, skeletal system, muscular system, excretory system, circulatory system, reproductive system, lining of body cavity, adrenal cortex, etc. Endoderm develops into: epithelial linings of digestive tract and respiratory system, lining on urethra, bladder, and reproductive system, liver, pancreas, thymus, etc. Germ Layers http://media.wiley.com/wires/WDEV/WDEV8/nfig001.jpg Organogenesis Process in which three embryonic germ layers develop into organs Notochord is formed from dorsal mesoderm (unique in vertebrate embryos) Neural crest is a band of cells that develop along the border where the neural tube pinches off from the ectoderm. Neural crest forms teeth, skull bones, etc. (fourth germ layer) Morphogenesis and cell differentiation refine the organs produced from the germ layers Somites, serially arranged on the notochord Dissociate into wandering cells that migrate to new locations Form muscles associated with axial skeleton Infertility Infertility is the inability to conceive and produce offspring Causes: Physical and emotional factors Female: autoimmune disorders, cancer, diabetes, eating disorders, older age, obesity, thyroid disease Male: pollutants, impotence, infection, birth defects, smoking, older age, STD’s, injury, surgery Three to seven percent of all couples worldwide are affected by infertility Symptoms: Inability to become pregnant, may cause painful emotions Treatment: education/counseling, fertility treatments, medicines treating infections and clotting disorders Cervical cancer Cancer beginning in the cervix (lower uterus) Starts as dysplasia, takes years for the cancer to develop Third most common type of cancer in women Causes: Develops slowly, HPV (virus spread through sexual intercourse), weakened immune system Symptoms: abnormal vaginal bleeding, longer and heavier periods, back pain, bone pain, fatigue, loss of appetite, pelvic pain, weight loss Treatment: depends on stage, size and shape of tumor, and woman’s age and health, hysterectomy (removal of uterus), radiation, chemotherapy Reproductive System Sources A.P. Bio book, Chapters 46 and 47 http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH00021 73/ http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH00018 95/ Nervous System The function of the nervous system is to send signals between cells. The nervous system controls and regulates movement and senses. The humans nervous system controls all mental activity, including thoughts, learning, and memory CNS & PNS Central Nervous System: small brain, longitudinal nerve cords in simple invertebrates (flatworms) CNS in vertebrates consists of the brain and spinal cord Complex invertebrates and arthropods have more complicated brains and ventral nerve cords with ganglia (clusters of neurons) Peripheral Nervous System: nerves that connect the CNS with the rest of the body PNS in vertebrates consists of nerves and ganglia Neuron Reflex arc Brain The right cerebral hemisphere deals with estimation and approximation calculation, contextual and intonation/accentuation in language The diencephalon regulates the activities of the autonomic nervous system and controls internal organ functions Uses the cranial nerves to provide motor and sensory function to face and neck; also regulates cardiac and respiratory function and CNS (maintains consciousness, regulates sleep cycle) The left hemisphere deals with exact calculation and direct fact retrieval, grammar/vocab and literal language Responsible for finite motor activity (precise, coordinated movement) and supervised learning Nerve Impulse Electric current travels across neurons (dendrites or axons) Ions move through voltage-gated channels that open and close in response to an electrical voltage. Sodium-potassium pumps push sodium out of cell, bringing potassium in. Cell exterior is positively charged while interior is negatively charged. Membrane potential is created. Stimuli cause the plasma membrane of a dendrite to open sodium channels, and the sodium ions flow into the cell (action potential) Now the interior is positively charged, while the exterior is negatively charged (depolarization). Membrane is repolarized when the potassium ions flow outward. Neurotransmitters Neurons communicate with electrical synapses (contain gap junction allowing electrical flow between cells) and chemical synapses Chemical synapses release neurotransmitters, packing it into synaptic vesicles. Neurotransmitters are released by exocytosis when the terminal membrane is depolarized, and the voltage-gated calcium channels are opened. EPSPs are excitatory postsynaptic potentials, where the depolarization of the postsynaptic membrane bring the membrane potential toward the threshold (the limit of most depolarizations) IPSPs are inhibitory postsynaptic potentials (hyperpolarizations produced when the potassium ion channels are opened) that move membrane potential away from the threshold. Direct Synaptic Transmission Schizophrenia A severe mental disturbance affecting around 1% of the worldwide population. Causes: Unknown, may be affected by genetics, may also be affected by unknown environmental factors Symptoms: Patient is unable to distinguish reality, hallucination, delusions, lack of emotion, difficulty sleeping, social isolation, anxiety, childlike behavior, attention problems, little or no response to other people Treatment: antipsychotic medication, supportive therapies and programs Parkinson’s Disease A disorder affecting motor function that inflicts about one million people in the U.S. Affects 1% of people at age 65, 5% at age 85 Cause: The destruction of dopamine-producing nerve cells, leading to loss of muscle function (brain cannot send proper messages) Symptoms: Blinking, drooling, difficulty swallowing, muscle aches, slowed movement, difficulty performing fine hand movements like writing, tremors, stooped position Treatment: No cure, Levodopa, Mirapex, Eldepryl are some drugs that reduce the symptoms; deep brain stimulation and surgery may be other symptom-easing options Nervous System Sources A.P. Bio book, Chapter 48 on Nervous Systems http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH00019 25/ http://faculty.southwest.tn.edu/rburkett/A&P1%20M13. jpg http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH00017 62/ Endocrine System The Endocrine System in charge of secreting chemicals that control the body’s metabolism. The Endocrine System produces hormones to influence tissue function, growth and development, metabolism, and reproductive function. The main glands are the hypothalamus, thyroid gland, adrenal gland, pancreas, and the ovaries in females and testes in males. Homeostasis The Endocrine System regulates the body’s temperature, pH, oxygen levels, and body systems, so the cells are at optimum performance. The thyroid gland is important in homeostatic functions. Hormones made in the thyroid gland maintain normal blood pressure, heart rate, muscle tone, digestion, and reproductive functions Feedback mechanisms have an important role in homeostasis. Feedback Mechanisms Negative feedback Process where the body reacts to reduce and eventually cease the stimulus Sweating when your temperature increases Positive feedback Process in which the stimulus is strengthened, increasing the response Ex: The mammary glands will continue to secrete milk as the baby suckles, and the pathway regulating the milk will continue to be stimulated Glands Diabetes I vs. II Diabetes I • Body’s own immune system kills pancreas cells that produce insulin • • Cause: unknown, possibly autoimmune disorder • Symptoms: Thirst, hunger, flushed face, stomach pain, headache, sweating, weakness • Treatment: Daily insulin injections, diet and exercise, blood sugar monitoring with glucometer Diabetes II • Most common type of Diabetes • Develops over time 8.3% of the • Causes: Body is unable to make proper use of insulin, Family U.S. history/genes, poor diet, excess population body weight has Diabetes • Symptoms: Fatigue, hunger, thirst, increased urination, blurred vision • Treatment: Exercise, diet, glucose monitoring, blood sugar management, weight control, some blood sugar regulating medications Thyroid cancer A cancer that begins in the thyroid gland. Occurs in all age groups. Causes: radiation therapy, family history, thyroid gland enlargement (goiter) Symptoms: Cough, difficulty swallowing, hoarseness, neck swelling, thyroid lump Treatment: Surgery (thyroid gland removal), radiation therapy and radioactive iodine, chemotherapy, thyroid hormone doses to make up for the gland removal One out of 97 (1.03%) men and women will get this disease. Endocrine System Sources A.P. Bio Book Chapter 45 http://www.pennmedicine.org/health_info/body_guide/refte xt/html/endo_sys_fin.html http://www.biology4kids.com/files/systems_regulation.html http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001350/ http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001356/ http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002193/ http://seer.cancer.gov/statfacts/html/thyro.html