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Slide 3: Levels of Structural Organization in an Animal Slide 4: TISSUES: Most animal cells are organized into tissues. Cooperative unit of very similar cells that perform a specific function. Tissue comes from Latin word meaning “weave”. Cells of tissues may be held together by: Fibers Glue-like substance Plasma membrane structures Tissue structure is related to its function. Slide 5: TISSUES: There are four main types of animal tissue: 1. Epithelial 2. Connective 3. Muscle 4. Nervous Slide 6: 1. Epithelial Tissue Cells are tightly fitted together in continuous layers or sheets. Cover outside of body (skin), line organs and internal body cavities (Mucous membranes of digestive, respiratory, and reproductive systems). Tight packaging allows tissue to act as a barrier to protect against mechanical injury, infection, and fluid loss. Two surfaces: Free surface: Exposed to air or fluid. Bottom surface: Attached to underlying tissues by a basement membrane, a dense layer of protein and polysaccharides. Slide 7: 1. Epithelial Tissue Can be classified based on two criteria: A. Number of layers: Simple: One layer. Stratified: Several layers B. Shape of cells: Squamous: Flat cells. Cuboidal: Cube shaped cells Columnar: Column shaped cells Example: Simple squamous epithelium Stratified columnar epithelium Slide 8: Epithelial Tissue Covers and Lines the Body and its Parts A. Simple squamous (Lung air sacs) D. Statified squamous (Lining esophagus) B. Simple cuboidal (Kidney tubes) C. Statified columnar (Lining intestine) Slide 9: 1. Epithelial Tissue Some epithelial tissues, such as mucous membranes, absorb and secrete chemical solutions. Mucous membranes: Digestive tract epithelium (mucous membranes) secretes mucus and digestive enzymes. Respiratory tract epithelium secretes mucous that helps trap dust particles before they reach the lungs. Slide 10: 2. Connective Tissue Relatively few cells surrounded by large amounts of nonliving material (matrix). Cells secrete the matrix, which can be solid, liquid, or gelatinous. Diverse functions. Mainly bind, support, and connect other tissues. Six types of connective tissue in humans: 1. Loose Connective Tissue: Most widespread connective tissue in vertebrates. Loose matrix with fibers, packing material. Attaches skin to muscles, binds and holds tissues and organs in place. 2. Adipose (fat): Pads and insulates body. Energy storage. Slide 11: Connective Tissue Binds and Provides Support A. Loose Connective Tissue B. Adipose Tissue C. Blood D. Fibrous Connective Tissue E. Cartilage F. Bone Slide 12: Types of connective tissue in humans (Continued): C. Blood: Fluid matrix (plasma) has water, salts, and proteins. Red and white blood cells. D. Fibrous Connective Tissue: Matrix of densely packed collagen fibers. Strong and nonelastic. Found in: Tendons: Attach muscles to bones. Ligaments: Attach bone to bone. E. Cartilage: Rubbery matrix with collagen fibers. Found on end of bones, nose, ears, and between vertebra. F. Bone: Supports the body of most vertebrates. Solid matrix of collagen fibers and calcium, phosphate, and magnesium salts. Bone is harder than cartilage, but not brittle because of collagen. Slide 13: 3. Muscle Tissue Most abundant type of tissue in most animals. Accounts for two-thirds (2/3) of human weight. Specialized for contraction. Made up of long cells that contract when stimulated by nerve impulses. Muscle cells have many microfilaments made up of actin and myosin. Muscle contraction accounts for much of energy consuming work in animals. Adults have a fixed number of muscle cells. Weight lifting doesn’t increase number of muscle cells, only their size. Slide 14: 3. Muscle Tissue There are three types of muscle tissue: A. Skeletal (striated) muscle : Attached to bones by tendons. Responsible for voluntary movements. B. Cardiac muscle: Forms contractile tissue of heart. Not under voluntary control. C. Smooth muscle: Found in walls of digestive tract, bladder, arteries, uterus, and many internal organs. Responsible for peristalsis and labor contractions. Contract more slowly than skeletal muscle, but can remain contracted longer. Not under voluntary control. Slide 15: A. Skeletal muscle B. Cardiac muscle C. Smooth muscle Three Types of Muscle Slide 16: 4. Nervous Tissue Senses stimuli and transmits signals from one part of the animal to another. Controls the activity of muscles and glands, and allows the animal to respond to its environment. Neuron: Nerve cell. Structural and functional unit of nervous tissue. Consists of: Cell body : Contains cell’s nucleus. Dendrite: Extension that conveys signals towards the cell body. Axon: Extension that transmits signals away from the cell body. Supporting cells: Nourish, protect, and insulate neurons. Slide 17: Nervous Tissue Forms a Communication Network Slide 18: Organs are made up of different tissues Organ: Several tissues that act as a unit and together perform one or more biological functions. Perform functions that component tissues can’t carry out alone. Example: The heart is an organ made up of: Muscle Tissue: Contraction Epithelial Tissue: Lines heart chambers to prevent leakage and provide a smooth surface. Connective Tissue: Makes heart elastic and strengthens its walls and valves. Nervous Tissue: Direct heart contractions. Organs are Made of Several Different Tissues : Organs are Made of Several Different Tissues Slide 20: Animals Regulate their Internal Environment Homeostasis: “Steady state”. Internal environment of animal remains fairly constant despite changes in the external environment. Control systems maintain internal conditions within a range in which life’s metabolic activities can occur. Homeostasis is a dynamic state resulting from changes in the outside environment and internal control mechanisms that oppose such changes. Slide 21: Homeostatic Mechanisms Counteract Changes in External Conditions Slide 22: Animals Regulate their Internal Environment Homeostasis: Maintained by negative feedback mechanisms. A change in one condition (e.g.: low body temperature), results is a response that counteracts that change (e.g.: shivering, etc.). Internal conditions regulated by negative feedback: Body temperature (Normal range: 97 - 100oF) Salt concentration pH Blood levels of sugar, calcium, oxygen, etc. Slide 23: Negative Feedback as Homeostatic Mechanism Slide 24: Body Temperature is Regulated by Homeostasis Slide 25: Major Organ Systems in Mammals Digestive system Respiratory system Circulatory system Cardiovascular Lymphatic and Immune system Excretory system Endocrine system Reproductive system Nervous system Muscular system Skeletal system Integumentary Slide 28: 1. Digestive System Components: Mouth, salivary glands, throat, esophagus, stomach, intestines, liver, gallbladder, pancreas, rectum, and anus. Functions: Ingest and mechanically break down food. Digest food: Stomach and small intestine mainly. Absorb nutrients and water. Eliminate waste. Homeostatic Roles: Supplies energy for life’s activities. Supplies building blocks for macromolecules Slide 29: Human Digestive System Obesity : Obesity Obesity is often diagnosed by using using a body mass index (BMI). BMI = w h 2 W = weight in kilograms H = height in meters Obesity in childhood is due to an increase in both the size and the # of adipocytes. Obesity defined as BMI > 30. Healthy weight as BMI between 19 – 25. Slide 34: 2. Respiratory System Components: Nose, throat, larynx, trachea, bronchi, and lungs. Functions: Exchange gases with the environment: Supplies blood with oxygen. Disposes of carbon dioxide (waste product from cellular respiration). Homeostatic Roles: Regulates blood pH. Regulates blood oxygen and carbon dioxide levels. Slide 35: Blood Transports Gases Between Lungs and Tissues Slide 36: Human Respiratory System Components: Nasal cavity, throat (pharynx), larynx (voice box), trachea, bronchi, alveoli, and lungs. Pathway of Inhaled Air: Nasal cavity Pharynx (Throat) Larynx (Voice Box) Trachea (Windpipe) Bronchi Bronchioles Alveoli (Site of gas exchange) Exhaled air follows reverse pathway. Slide 37: Blood Transports Gases Between Lungs and Tissues Slide 41: Human Respiratory System 1. Nasal cavity: Air enters nostrils, is filtered by hairs, warmed, humidified, and sampled for odors as it flows through a maze of spaces. 2. Pharynx (Throat): Intersection where pathway for air and food cross. Most of the time, the pathway for air is open, except when we swallow. 3. Larynx (Voice Box): Reinforced with cartilage. Contains vocal cords, which allow us to make sounds by voluntarily tensing muscles. High pitched sounds: Vocal cords are tense, vibrate fast. Low pitched sounds: Vocal cords are relaxed, vibrate slowly. More prominent in males (Adam’s apple). Slide 42: Human Respiratory System 4. Trachea (Windpipe): Rings of cartilage maintain shape of trachea, to prevent it from closing. Forks into two bronchi. 5. Bronchi (Sing. Bronchus): Each bronchus leads into a lung and branches into smaller and smaller bronchioles, resembling an inverted tree. 6. Bronchioles: Fine tubes that allow passage of air. Muscle layer constricts bronchioles. Epithelium of bronchioles is covered with cilia and mucus. Mucus traps dust and other particles. Ciliary Escalator: Cilia beat upwards and remove trapped particles from lower respiratory airways. Rate about 1 to 3 cm per hour. Pulmonary Function Tests : Pulmonary Function Tests Assessed by spirometry. Subject breathes into a closed system in which air is trapped within a bell floating in H20. The bell moves up when the subject exhales and down when the subject inhales. Spirogram : Spirogram Tidal volume: Amount of air expired with each breath. Vital capacity: The maximum amount of air that can be forcefully exhaled after maximum inhalation. Slide 47: Table 16.3 Terms Used to Describe Lung Volumes and Capacities Term Definition Lung Volumes The four nonoverlapping components of the total lung capacity Tidal volume The volume of gas inspired or expired in an unforced respiratory cycle Inspiratory reserve volume The maximum volume of gas that can be inspired during forced breathing in addition to tidal volume Expiratory reserve volume The maximum volume of gas that can be expired during forced breathing in addition to tidal volume Residual volume The volume of gas remaining in the lungs after a maximum expiration Lung Capacities Measurements that are the sum of two or more lung volumes Total lung capacity The total amount of gas in the lungs after a maximum inspiration Vital capacity The maximum amount of gas that can be expired after a maximum inspiration Inspiratory capacity The maximum amount of gas that can be inspired after a normal tidal expiration Functional residual capacity The amount of gas remaining in the lungs after a normal tidal expiration Restrictive and Obstructive Disorders : Restrictive and Obstructive Disorders Restrictive disorder: Vital capacity is reduced. FVC is normal. Obstructive disorder: VC is normal. FEV1 is reduced. Slide 49: Hemoglobin helps transport CO2 and buffer blood Hemoglobin is found in red blood cells Functions: Transports oxygen Transport carbon dioxide Helps buffer blood As carbon dioxide is picked up from tissues it is converted into carbonic acid: CO2 + H2O <-----> H2CO3 <----> H+ + HCO3 - Carbon Carbonic acid Carbonate ion dioxide Hemoglobin picks up most H + ions, so they don’t acidify the blood. Respiratory Acid-Base Balance : Respiratory Acid-Base Balance Ventilation normally adjusted to keep pace with metabolic rate. H2CO3 produced converted to CO2, and excreted by the lungs. H20 + C02 H2C03 H+ + HC03- Slide 54: Diseases of the Respiratory System Respiratory rate: 10 to 14 inhalations/minute. In one day, an average human: Breathes 20,000 times Inhales 35 pounds of air Most of us breathe in air that is heavily contaminated with solid particles, ozone, sulfur oxide, carbon monoxide, nitrogen oxides, and many other damaging chemicals. Breathing contaminated air can cause a number of diseases including asthma, bronchitis, emphysema, and lung cancer. Slide 55: Diseases of the Respiratory System Lung Cancer: Cancerous growth that invades and destroys lung tissue. Very high fatality rate. Symptoms include bloody sputum, persistent cough, difficulty breathing, chest pain, and repeated attacks of bronchitis or pneumonia. Causes: Smoking (50% of all cases) and pollution (radon, asbestos). Smokers are 10 times more likely to develop lung cancer than nonsmokers. Treatment: Surgery is most effective, but only 50% of all lung cancers are operable by time of detection. Other treatments include radiation and chemotherapy. Slide 57: 3. Cardiovascular System Components: Blood, heart, arteries, veins, and capillaries. Functions: Exchange gases with the respiratory system. Supplies tissues with oxygen. Removes carbon dioxide from tissues. Transports materials (nutrients, hormones, etc.) inside body. Defends against infection. Homeostatic Roles: Provides nutrients and removes waste materials from tissues. Regulates body temperature, water and ion balance. Slide 58: Human Cardiovascular System Slide 59: 1. Blood Average Blood Volume: 4 to 6 liters. Blood composition: 55% Plasma (fluid matrix of water, salts, proteins, etc.) 45% Cellular elements: Red Blood Cells (RBCs): 5-6 million RBCs/ml of blood. Contain hemoglobin which transport oxygen and CO2. White Blood Cells (WBCs): 5,000-10,000 WBCs/ml of blood. Play an essential role in immunity and defense. Include: Lymphocytes: T cells and B cells Macrophages (phagocytes) Granulocytes: Neutrophils, basophils, and eosinophils. Platelets: Cellular fragments. 250,000- 400,000/ml of blood. Important in blood clotting. Slide 60: Types of Blood Vessels A. Arteries and Arterioles: Carry blood away from heart to body. Have high pressure. Have thick muscular walls, which make them elastic and contractile. Vasoconstriction: Arteries contract: Reducing flow of blood into capillaries. Increasing blood pressure. Vasodilation: Arteries relax: Increasing blood flow into capillaries. Decreasing blood pressure. Slide 61: Types of Blood Vessels Capillaries: Only blood vessels whose walls are thin enough to permit gas exchange. Blood flows through capillaries relatively slowly, allowing sufficient time for diffusion or active transport of substances across walls. Only about 5 to 10% of capillaries have blood flowing through them. Only a few organs (brain and heart) always carry full load of blood. Blood flow to different organs is controlled by precapillary sphincters of smooth muscle. Slide 62: Types of Blood Vessels Veins and Venules: Collect blood from all tissues and organs and carry it back towards heart. Have low pressure and thin walls. Veins have small valves that prevent backflow of blood towards capillaries, especially when standing. If the valves cease to work properly, may result in: Varicose veins: Distended veins in thighs and legs. Hemorroids: Distended veins and inflammation of the rectal and anal areas. Red Blood Cell Antigens : Red Blood Cell Antigens ABO system: Major group of antigens of RBCs. Type A: Only A antigens present. Type B: Only B antigens present. Type AB: Both A and B antigens present. Type O: Neither A or B antigens present. Transfusion Reactions : Transfusion Reactions If blood types do not match, the recipient’s antibodies attach to donor’s RBCs and agglutinate. Type O: Universal donor. Recipient’s antibodies cannot agglutinate the donor’s RBCs. Type AB universal recipient: Lack the anti-A and anti-B antibodies. Cannot agglutinate donor’s RBCs. Rh Factor : Rh Factor Another group of antigens found on RBCs. Rh positive: Have these antigens. Rh negative: Do not have these antigens. Significant when Rh negative mother give birth to Rh positive baby. At birth, mother may become exposed to Rh positive blood of fetus. Mother at subsequent pregnancies may produce antibodies against the Rh factor. Slide 68: Heart Anatomical Features: Hollow muscular organ, about the size of a human fist. Weighs less than one pound (10 ounces). Rests on diaphragm, near middle of thoracic cavity. Wall is composed of cardiac muscle covered by connective tissue. Pericardium: Membrane that surrounds entire heart and contains a fluid which protects heart and decreases friction. Slide 69: Heart Heart Chambers: Heart is divided into four separate chambers. Both the left and the right side of the heart have a(an): Atrium (Plural atria): Smaller, superior chambers. Receive blood from veins. Ventricle: Larger, inferior chambers. Pump blood into arteries. Two sides of heart have different functions: Right side: Pumps oxygen poor blood. Left side: Pumps oxygen rich blood. Slide 72: Pacemaker (Sinoatrial node): Specialized structure that sends electrical impulses that causes both atria and ventricles to contract. Slide 73: Heart Heart Valves: Heart has several valves made of connective tissue, that prevent backflow of blood as it circulates. Atrioventricular (AV) Valves: Close between atria and ventricles Right AV Valve: Connects right atrium to the right ventricle. Left AV Valve: Connects left atrium to the left ventricle. Semilunar Valves: Close as blood leaves the ventricles and enters the arteries. Heart murmur: Rushing, gurgling sound created by backflow of blood due to damaged or imperfect heart valves. Fairly common (10% of healthy population). Most are asymptomatic. Slide 74: Heart Beat Average 70 beats per minute. 100,000 beats every day. Cardiac cycle about every 0.8 sec. Diastole: Heart relaxes and blood flows into chambers (0.4 sec). Systole: Heart contracts. First atria (0.1 sec) Then ventricles (0.3 sec) Pumps about 8000 liters of blood/day. Pacemaker (Sinoatrial node): Controls heart rate. Regulated by nervous and endocrine systems. Two heart beat sounds (“Lub-dupp”): First sound: Ventricles contract, AV valves close. Second sound: Heart relaxes, semilunar valves are closing. Pulse: Arteries expand and contract with each heartbeat. Slide 76: Pacemaker Controls Cardiac Rhythm Slide 79: Blood Pressure Pressure is highest in arteries; lowest in veins. “Blood pressure” usually refers to arterial pressure. Usually measured at brachial artery in arm. Two measurements: Systolic Blood Pressure: During heart contraction. Normal systolic pressure is about 120 mm Hg. (Range: 110-140 mm Hg). Diastolic Blood Pressure: During heart relaxation. Normal diastolic pressure is about 80 mm Hg. (Range: 70-90 mm Hg) Slide 81: Blood Pathway in Body Right Side of Heart: Right atrium receives oxygen poor blood from body. Right ventricle pumps oxygen poor blood to lungs. Left Side of Heart: Left atrium receives oxygenated blood from lungs. Left ventricle pumps oxygenated blood to body. Blood Pathway: Veins Vena cava Right atrium Right AV Valve (Tricuspid) Right ventricle Pulmonary Semilunar Valve Pulmonary arteries Lungs Pulmonary veins Left atrium Left AV Valve (Bicuspid or Mitral Valve) Left ventricle Aortic Semilunar Valve Aorta Arteries Capillaries Veins Slide 87: Cardiovascular Disease Number one cause of death in the U.S. and industrialized nations. Includes hypertension, strokes, heart attacks, and congestive heart failure. Most often caused by complications of: Arteriosclerosis: A condition in which arteries become blocked by calcium and lipid deposits (plaque), losing their elasticity. Slide 88: Heart Attack (Myocardial infarction-MI) Sudden decrease in blood supply to the heart, due to a clot or plaque in arteries. Death of cardiac muscle resulting in insufficient blood supply to rest of body. Heart may stop beating altogether or suffer permanent damage. Over 7.9 Million heart attacks every year in U.S. (2004) Leading cause of death and disability 60% had no previous symptoms. 25% are not recognized when they occur. Heart Attacks are Caused by Blocked Coronary Arteries : Heart Attacks are Caused by Blocked Coronary Arteries Slide 90: Heart Attack (Myocardial infarction) Symptoms: Chest pain, pressure, or tightness, sweating, nausea, shortness of breath, dizziness, and fainting. Risk factors: Smoking High blood pressure High cholesterol High LDLs (low density lipoproteins) Diabetes Male gender Emotional stress Obesity Heredity Sedentary lifestyle Slide 96: 4. Lymphatic and Immune System Components: Lymph, lymphatic vessels, bone marrow, thymus, spleen, and lymph nodes. Functions: Defends against infection: bacteria, fungi, viruses, etc. Destruction of cancer and foreign cells. Synthesis of antibodies and other immune molecules. Synthesis of white blood cells. Homeostatic Role: Returns fluid and proteins that have leaked from blood capillaries into tissues. Up to 4 liters of fluid every day. Fluid returned near heart/venae cavae. Slide 97: Lymphatic and Immune Systems Slide 98: Introduction Resistance: Ability to ward off disease. Nonspecific Resistance: Defenses that protect against all pathogens. Specific Resistance: Protection against specific pathogens. Susceptibility: Vulnerability or lack of resistance. Slide 99: Protection Against Invading Pathogens 1. First Line of Defense: Non-specific natural barriers which restrict entry of pathogen. Examples: Skin and mucous membranes. 2. Second Line of Defense: Non-specific defenses that provide rapid local response to pathogen after it has entered body. Examples: Fever, phagocytes (macrophages and neutrophils), inflammation, and interferon. 3. Third line of defense: Antigen-specific immune responses, specifically target and attack invaders that get past first two lines of defense. Examples: Antibodies and lymphocytes. Defenses Against Infection : Defenses Against Infection Slide 101: The Immune Response Destroys Specific Invaders Antigen: Molecule that elicits an immune response. “Antibody generating”. Microbial antigens: Viral capsid, bacterial cell wall, etc. Nonmicrobial antigens: Pollen, latex, food, etc. Antibody: Protein found in blood plasma that attaches to antigen and helps counteract its effects. Vaccination or Immunization: Process in which harmless forms of antigen or pathogen are introduced into body to provoke an immune response. Diseases Caused by the Immune System : Diseases Caused by the Immune System Ability of immune system to tolerate self-antigens while it identifies and attacks foreign antigens that can be deranged. Diseases caused by the immune system can be grouped into 3 categories: Autoimmune disease. Immune complex diseases. Allergy or hypersensitivity. Autoimmunity : Autoimmunity Those produced by failure in the immune system to recognize and tolerate self-antigens. Failure due to: An antigen that does not normally circulate in the blood may be exposed to the immune system. Thyroglobulin. A self-antigen that is otherwise tolerated may be altered by combining with a foreign hapten. Thrombocytopenia. Autoimmunity : Autoimmunity Antibodies may be produced that are directed against other antibodies. Rheumatoid arthritis. Antibodies produced against foreign antigens may cross-react with self-antigens. Rheumatic fever. Self-antigens may be presented to the helper T cells together with class-2 MHC molecules. Type I diabetes. Slide 106: 5. Excretory (Urinary) System Components: Kidneys, bladder, urethra, and associated ducts. Functions: Kidneys remove nitrogen containing waste from blood. Urine with waste is temporarily stored in bladder. Excretion of urine. Homeostatic Role: Regulates water levels in body. Removes excess water Helps conserve water Slide 107: Human Excretory System Renal Acid-Base Regulation : Renal Acid-Base Regulation Kidneys help regulate blood pH by excreting H+ and reabsorbing HC03-. Most of the H+ secretion occurs across the walls of the PCT in exchange for Na+. Antiport mechanism. Normal urine normally is slightly acidic because the kidneys reabsorb almost all HC03- and excrete H+. Returns blood pH back to normal range. Reabsorption of HCO3- : Reabsorption of HCO3- Apical membranes are impermeable to HCO3-. Reabsorption is indirect. HCO3- combines with H+ to form H2C03, which is catalyzed by carbonic anhydrase (ca) located in the apical cell membrane of PCT. As [C02] increases in the filtrate, ca forms H2C03. H2C03 dissociates to HCO3- and H+. Shunt HCO3- generated within tubule cell to peritubular capillary. Urinary Buffers : Urinary Buffers Nephron cannot produce a urine pH < 4.5. IN order to excrete more H+, the acid must be buffered. H+ secreted into the urine tubule and combines with HPO4-2 or NH3. HPO4-2 + H+ H2PO4-2 NH3 + H+ NH4+ Diuretics : Diuretics Increase urine volume excreted. Increase the proportion of glomerular filtrate that is excreted as urine. Loop diuretics: Inhibit NaCl transport out of the ascending limb of the LH. Thiazide diuretics: Inhibit NaCl reabsorption in the DCT. Ca inhibitors: Prevent H20 reabsorption when HC03- is reabsorbed. Osmotic diuretics: Increase osmotic pressure of filtrate. Slide 115: 6. Endocrine System Components: Pituitary, adrenal, thyroid, thymus, pancreas, ovaries, testes, and other ductless glands. Functions: Produce hormones that regulate: Blood chemistry: Levels of sugars, minerals, etc. Reproduction Growth Metabolism Digestion Homeostatic Role: With nervous system, regulates metabolism and blood chemistry. Slide 116: Human Endocrine System Hormones : Hormones Regulatory molecules secreted into the blood or lymph by endocrine glands. Lack ducts. Carry hormone to target tissue where it produces its effects. Posterior Pituitary : Also called the neurohypophysis. Formed by downgrowth of the brain during fetal development. Is in contact with the infundibulum. Nerve fibers extend through the infundibulum. Posterior Pituitary Hypothalamic Control of Posterior Pituitary : Hypothalamic Control of Posterior Pituitary Hypothalamus produces: ADH: supraoptic nuclei. Oxytocin: paraventricular nuclei. Hormones transported along the hypothalamo-hypophyseal tract. Stored in posterior pituitary. Release controlled by neuroendocrine reflexes. Anterior Pituitary : Master gland (also called adenohypophysis). Derived from a pouch of epithelial tissue that migrates upward from the mouth. Consists of 2 parts: Pars distalis: anterior pituitary. Pars tuberalis: thin extension in contact with the infundibulum. Anterior Pituitary Anterior Pituitary : Trophic effects: Health of the target glands, depends upon stimulation by anterior pituitary for growth. High plasma hormone concentration causes target organ to hypertrophy. Low plasma hormone concentration causes target organ to atrophy. Anterior Pituitary Growth Hormone (GH) - Somatotrophic Hormone (STH) : Growth Hormone (GH) - Somatotrophic Hormone (STH) Increases Growth and Maintenance of Organs by: stimulating protein anabolism promotes fat catabolism (use of fat rather than sugars for energy) Abnormal Secretions of STH Giantism -- hypersecretion during childhood (before epiphyseal plates close) Acromegaly -- hypersecretion during adulthood Dwarfism -- hyposecretion during childhood Cachexia (Simmond's Disease) - hyposecretion during adulthood causes premature aging and atrophy of organs Thyroid Hormones : Thyroid Hormones Thyroid gland located just below the larynx. Thyroid is the largest of the pure endocrine glands. Follicular cells secrete thyroxine. Parafollicular cells secrete calcitonin. Parathyroid Hormone : Parathyroid Hormone Parathyroid glands embedded in the lateral lobes of the thyroid gland. Only hormone secreted by the parathyroid glands. Single most important hormone in the control of plasma Ca++ concentration. Stimulated by decreased plasma Ca++ concentration. Adrenal Glands : Adrenal Glands Paired organs that cap the kidneys. Each gland consists of an outer cortex and inner medulla. Adrenal medulla: Derived from embryonic neural crest ectoderm (sympathetic ganglia). Synthesizes and secretes: Catecholamines (mainly epinephrine but some norepinephrine). Adrenal Glands : Adrenal Glands Adrenal cortex: Does not receive neural innervation. Must be stimulated hormonally. Consists of 3 zones: Zona glomerulosa: Aldosterone: regulate Na+ and K+ balance. Zona fasciculata: Cortisol: regulate glucose metabolism. Zona reticularis: Androstenedione and DHEA: supplement sex steroids. Adrenal Medulla : Adrenal Medulla Innervated by sympathetic nerve fibers. Increase respiratory rate. Increase heart rate, cardiac output; and vasoconstrict blood vessels, thus increasing venous return. Stimulate glycogenolysis. Stimulate lipolysis. Pancreas : Pancreas Endocrine portion consists of islets of Langerhans. Alpha cells secrete glucagon. Stimulus is decrease in plasma glucose concentrations. Stimulates lipolysis. Beta cells secrete insulin. Stimulus is increase in plasma glucose concentrations. Promotes entry of glucose into cells. Diabetes Mellitus : Diabetes Mellitus Type I (insulin-dependent) diabetes Pancreas does not produce insulin T cells destroy pancreatic islets Needs daily insulin injections Type II (noninsulin-dependent) diabetes Most common type of diabetes Obesity and inactivity are risk factors Insulin is produced, but there is decreased response to the insulin perhaps because of a lack or deficiency in insulin receptors. Consequences: May lead to blindness, kidney disease, & circulatory disorders like atherosclerosis, heart disease, and stroke. Lack of circulation may also cause gangrene. Diabetic coma may also result and there is an increased risk of having a stillborn child. Slide 139: 7. Reproductive System Components: Female: Ovaries, oviduct, uterus, vagina, and associated structures Male: Testes, seminal vesicles, prostate, urethra, penis, and associated structures. Functions: Only organ system that is not essential for individual survival. Continuation of species. Gamete formation (eggs and sperm cells). Homeostatic Role: Maintains secondary sexual characteristics. Slide 140: Reproductive System of Humans Reproductive Functions of Male: Produces sperm Delivers sperm to female reproductive tract All of these processes are regulated and coordinated by hormones secreted by: Hypothalamus Pituitary gland (anterior portion) Testes (Sing. Testis) Slide 141: Male Reproductive System Slide 142: Major Organs of Male Reproductive System: Testes: Paired male gonads. Produce sperm through spermatogenesis, which produces four sperm cells of equal size. Spermatogenesis occurs in a vast system of hollow tubes called seminiferous tubules. Each mature sperm has a head, a midpiece, and a flagellum. Sperm head has an acrosome, which produces enzymes that help it penetrate the egg. Human sperm cannot develop at body temperature. Testicles descend from abdominal cavity into scrotum, a skin covered sac, about two months before birth. Undescended testicles (cryptorchidism) may cause infertility. Slide 143: Reproductive System of Humans Major Organs of Male Reproductive System: Epididymus: Large coiled tube (23 ft long) that surrounds testes. Stores sperm while they develop fertilizing ability and motility (about 20 days). During ejaculation, sperm cells are propelled from epididymus. Vas Deferens: Long muscular ducts from scrotum to back of bladder. During ejaculation, the sperm pass from epididymus into these two ducts. Vasectomy: Each vas deferens is cut to prevent sperm from entering urethra. Slide 144: Reproductive System of Humans Major Organs of Male Reproductive System: Ejaculatory Duct: Short duct after two vas deferens ducts unite. Urethra: Deliver sperm to the exterior. In males, urine and sperm pass through the urethra. Females have a separate urethra from the reproductive system. Slide 145: Reproductive System of Humans Major Organs of Male Reproductive System: Accessory Glands: Produce semen. Functions of semen: Activate sperm cells Provide nutrients for motility Counteract acidity of vagina and male urethra Stimulate contractions of female reproductive tract Antimicrobial action Ejaculation volume 4 to 5 ml. One ejaculation has 50-500 million sperm cells Sperm cells account for less than 5% of semen volume. Secretions from 3 different accessory glands make up the rest of the volume: Seminal vesicles (2), prostate, and bulbourethral glands (2). Slide 146: Major Organs of Male Reproductive System: Accessory Glands: A. Seminal vesicles (2): Secrete fluid that nourishes sperm. Contribute about 60% of semen volume. Thick, clear, alkaline fluid. Contains: Fructose: Provides energy for sperm motility. Prostaglandins: Stimulate smooth muscle contractions of female and male reproductive tracts. Fibrinogen: Forms temporary clot in vagina. Sperm cells become highly motile when mixed with this fluid. Slide 147: Accessory Glands: B. Prostate gland: Produces a thin milky secretion. Largest of semen secreting glands. Contributes 30% of semen volume. Produces an antibiotic that may prevent urinary tract infections in men. Benign (noncancerous) prostate enlargement is common among older men. 50% of men over 40. Almost all men over 70. Prostate cancer is the second leading cause of cancer and cancer deaths in men. Over 330,000 new cases/year and 40,000 deaths. Average age at diagnosis: 72 Detected by blood test or digital rectal exam. Treated surgically or with drugs to reduce prostate size or activity. Slide 148: Major Organs of Male Reproductive System: Accesory Glands: C. Bulbourethral glands (2): Release a mucous secretion that lubricates penis and facilitates its entry into vagina. Pair of small glands below the prostate. Contribute 5-10% of semen volume. Before ejaculation secrete a clear mucus that neutralizes acid from remaining urine in urethra. Bulbourethral fluid also carries some sperm that is released before ejaculation. One cause of high failure rate of withdrawal method. Slide 149: Major Organs of Male Reproductive System: Penis: Copulatory organ that delivers sperm to female body. Composed of three cylinders of erectile tissue. During sexual arousal, the penis fills with blood from the arteries. Erection is essential for penetration. Impotence is the inability to maintain an erection. May be caused by alcohol, drugs, illness, and/or emotional problems. Viagra acts by relaxing smooth muscle of penis blood vessels, allowing blood to enter erectile tissue. Penis structure: Shaft: Long cylinder with thick skin. Glans: Enlarged tip of penis. Thin skin, covered by prepuce or foreskin. Slide 150: Reproductive System of Humans Reproductive Functions of Female: Produces eggs (ova) Receives sperm Incubates and nourishes the embryo and fetus Gives birth Produces milk for young All of these processes are regulated and coordinated by hormones secreted by: Hypothalamus Pituitary gland (anterior portion) Ovaries Slide 151: Female Reproductive System Slide 152: Reproductive System of Humans Major Organs of Female Reproductive System: Ovaries: Produce ova (oogenesis) and sex hormones. Size and shape of large almonds. Located close to lateral walls of pelvic cavity and held in place by connective tissue. Mainly connective tissue containing scattered eggs (ova) in different stages of development. Follicles: A single egg with surrounding cells that nourish and protect it. Women are born with all of their follicles (40,000 to 400,000). Only a fraction of follicles release eggs during a woman’s reproductive life. Slide 153: Female Reproductive System: Ovulation & Oogenesis: After puberty, each month one immature egg (oocyte), is released from ovary. Each follicle contains a primary oocyte, arrested in prophase I of meiosis. Pituitary hormones FSH (follicle stimulating hormone) and LH (luteinizing hormone) cause a follicle to enlarge and complete meiosis I. One large cell (secondary oocyte) and a tiny cell (polar body) are produced. LH (luteinizing hormone) causes the secondary oocyte to be released by the ovary during ovulation. Oocyte will not finish meiotic division, until fertilized. In the end, one large ovum (egg) and 3 small polar bodies are made from oogenesis. Slide 154: Major Organs of Female Reproductive System: Oviducts (Fallopian Tubes): Transport the egg from the ovary to the uterus. Peristalsis of smooth muscle in oviduct and beating of cilia, help the egg move along. Fertilization occurs in the first third of oviduct. Scarring of oviducts is a common consequence of sexually transmitted diseases: chlamydia and gonorrhea. Ectopic Pregnancy: Fertilized egg does not reach the uterus. Usually starts to develop in oviduct. Usually due to a blocked oviduct. Occurs in 1% of all pregnancies in the U.S. Must be surgically removed. May cause death and severe hemorrhage. Slide 155: Reproductive System of Humans Major Organs of Female Reproductive System: Uterus: Incubates the embryo/fetus. Size of a fist, in center of pelvic cavity. Oviducts open into upper corners of uterus. Has thick walls of smooth muscle (myometrium) responsible for uterine contractions and cramps. Endometrium: Inner mucous lining, which thickens each month in preparation for pregnancy. If fertilization does not occur, endometrium breaks down and is discharged during menstruation. If fertilization occurs, the egg implants in the endometrium which supports its growth until the placenta develops. Slide 156: Reproductive System of Humans Major Organs of Female Reproductive System: Cervix: Lower portion of the uterus, which projects into the vagina. Pap smear: Examination of cervical tissue to detect abnormalities. Recommended yearly. Cervical cancer: Most cases caused by a viral infection with human papillomavirus. Women are infected through intercourse with asymptomatic male. Takes about 20 to 30 years to develop. Men don’t appear to be affected. Slide 157: Reproductive System of Humans Major Organs of Female Reproductive System: Vagina: Thin walled, muscular chamber. Receives the sperm and penis Acid pH kills bacteria and sperm cells Part of birth canal Vulva: External structures. Clitoris: Equivalent to male penis. Labia minora: Skin folds that border vaginal opening. Labia majora: Protect entire genital region. Hymen: Ring of tissue that forms a border around vaginal entrance. No known function. Bartholin’s gland: Secrete lubricating fluid during sexual arousal. Breasts: Lactation Slide 160: 8. Nervous System Components: Brain, spinal cord, nerves, sense organs, and associated structures. Functions: Works with endocrine system to coordinate body activities. Integrates and processes information from sense organs. Sends signals (instructions) to muscles and glands. Responds to internal stimuli. Homeostatic Role: Regulates most organ activities along with endocrine system. Slide 161: Human Nervous System Slide 162: Functions of Nervous Tissue 1. Sensory Input: Conduction of signals from sensory organs (eyes, ears, nose, skin, etc.) to information processing centers (brain and spinal cord). 2. Integration: Interpretation of sensory signals and development of a response. Occurs in brain and spinal cord. 3. Motor Output: Conduction of signals from brain or spinal cord to effector organs (muscles or glands). Controls the activity of muscles and glands, and allows the animal to respond to its environment. Slide 163: Nervous System Allows Us to Respond to Our Environment Slide 164: Cells of Nervous Tissue 1. Neuron: Nerve cell. Structural and functional unit of nervous tissue. Carry signals from one part of the body to another. 2. Supporting cells: Nourish, protect, and insulate neurons. There are roughly 50 supporting cells for every neuron. In humans, Schwann cells wrap around the axons of neurons, forming a myelin sheath that is essential for transmission of nerve impulses. Slide 165: Neuron Structure Cell body : Contains nucleus and most organelles. Dendrites: Extensions that convey signals towards the cell body. Short, numerous, and highly branched Axon: Extension that transmits signals away from the cell body to another neuron or effector cell. Usually a long single fiber. Axon is covered by a myelin sheath made up of many Schwann cells that are separated by small spaces (Nodes of Ranvier). Slide 166: Structure of the Neuron Slide 167: Neuron Structure Myelin sheath and nodes of Ranvier greatly speed up nerve impulses, which jump down axon from node to node. Speed of signal Myelinated axon 100 meters/second Unmyelinated axon 5 meters/second Multiple sclerosis: A disease in which a person’s immune system destroys the myelin sheaths on their neurons. Loss of muscle control Impaired brain function Death Slide 168: What is a Nerve Impulse? An electrical signal that depends on the flow of ions across the neuron plasma membrane. Resting Potential: A neuron at rest has a net negative charge (-70 mV, equivalent to 5% of the voltage in AA battery). The net negative charge is due to different ion concentrations across the neuron membrane. Slide 170: What is a Nerve Impulse? An electrical signal that depends on the flow of ions across the neuron plasma membrane. Action Potential: When a neuron is stimulated above a certain threshold, this causes: 1. Depolarization: An influx of positive ions (Na+) into the cell, caused by the opening of sodium channels. The inside of the cell becomes positively charged for a brief moment (1-2 milliseconds). 2. Repolarization: After a few milliseconds, the neuron allows other positive ions (K+) to leave the cell so the inside of the cell becomes negatively charged once again. Resting Potential is Caused by Differences in Ion Concentrations Across Neuron Membrane : Resting Potential is Caused by Differences in Ion Concentrations Across Neuron Membrane Action Potential Requires Stimulus Above a Certain Threshold : Action Potential Requires Stimulus Above a Certain Threshold Nerve Impulses are Caused by Action Potentials : Nerve Impulses are Caused by Action Potentials Slide 176: Neurons Communicate at Synapses Synapse: Junction between two neurons or a neuron and an effector cell (muscle or gland). There are two types of synapses: 1. Electrical Synapse: Found in heart and digestive tract of human body. Action potentials pass directly from one neuron to another. 2. Chemical Synapse: Found in CNS, muscles, and most other organs. Require neurotransmitters: Chemicals that convey messages from one neuron to another. Transmitting neuron releases neurotransmitters which cross synapse and cause an action potential in the receiving neuron. Synapse : Synapse Functional connection between a neuron and another cell. Different types of synapses involve: Axonodendritic: Axon of one neuron and dendrite of another neuron. Axosomatic: Axon of one neuron and cell body of another neuron. Axoaxonic: Axon of 1 neuron and axon of another neuron. Transmission in one direction only. Chemical Synapses Use Neurotransmitters : Chemical Synapses Use Neurotransmitters Diseases of the Nervous System : Diseases of the Nervous System I. Alzheimer’s Disease Most common form of dementia in U.S. Unknown cause, probably both genetic and environmental factors are important. No effective treatment Certain diagnosis is usually only possible through discovery of typical brain lesions during autopsy. Usually affects elderly: Over 4 million cases in U.S. 10% of those over 65 Almost half of those over 85 Symptoms progress over time. Three stages: Mild Stage: Forgetfulness, minor disorientation, mild personality changes, depression, difficulty in finding right words during conversation, and performing arithmetic calculations (e.g.: balancing checkbook). Diseases of the Nervous System : Diseases of the Nervous System I. Alzheimer’s Disease (Continued) Stages of Alzheimer’s Disease: Moderate Stage: Noticeable memory loss, difficulty performing everyday tasks (bathing, dressing, cooking, driving, operating appliances), may wander off, confuse day and night, fails to recognize acquaintances and distant relatives. Severe Stage: Very limited speech (less than 12 words), eventually becomes mute and uncomprehending, loses all self-care ability, can’t recognize closest relatives, friends, or caregivers, becomes incontinent, progressively loses ability to walk, stand, sit up, smile, and hold head up. Many patients die from complications like pneumonia. Brain Atrophy in Alzheimer’s Disease : Brain Atrophy in Alzheimer’s Disease Definite diagnosis of Alzheimer’s usually requires post-mortem brain examination. Notice pronounced atrophy with wide sulci (grooves) in frontal and parietal regions. Source: www-medlib.med.utah.edu/WebPath/CNSHTML Slide 188: 9. Muscular System Components: Skeletal muscles. Functions: Skeletal muscle contraction allows for voluntary movement: Movement and locomotion. Mechanical work: Lifting, pulling, pushing objects. Communication: Body language and facial expression. Homeostatic Role: Allows animals to respond to and control their environment. Slide 189: Muscular System: Skeletal Muscle Allows Voluntary Movement Slide 197: 10. Skeletal System Components: Bones, ligaments, and cartilage. Functions: Along with muscular system: Movement and locomotion. Mechanical work: Lifting, pulling, pushing objects. Body support. Protection of delicate internal organs (brain, heart, lungs, etc.) Calcium storage Homeostatic Role: Helps maintain constant blood calcium levels. Slide 198: Skeletal System: Protection, Movement, & Support Slide 201: 11. Integumentary System Components: Hair, skin, and nails. Functions: Protects the body from: Infection: Barrier to microbes. Mechanical injury Excessive heat or cold: Thermoregulation Water loss Communication: Receives stimuli from environment Gives out subtle signals (blushing, etc.). Homeostatic Role: Helps maintain constant body temperature. Slide 202: Integumentary System: Skin, Nails, & Hair Slide 204: Organ systems must be coordinated for animal to survive Organ systems interact with one another in order to maintain fairly stable conditions (homeostasis) that are required for life. Example: Interactions between: Respiratory Circulatory Digestive Slide 205: Relationships Between Several Major Organ Systems You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
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Slide 3: Levels of Structural Organization in an Animal Slide 4: TISSUES: Most animal cells are organized into tissues. Cooperative unit of very similar cells that perform a specific function. Tissue comes from Latin word meaning “weave”. Cells of tissues may be held together by: Fibers Glue-like substance Plasma membrane structures Tissue structure is related to its function. Slide 5: TISSUES: There are four main types of animal tissue: 1. Epithelial 2. Connective 3. Muscle 4. Nervous Slide 6: 1. Epithelial Tissue Cells are tightly fitted together in continuous layers or sheets. Cover outside of body (skin), line organs and internal body cavities (Mucous membranes of digestive, respiratory, and reproductive systems). Tight packaging allows tissue to act as a barrier to protect against mechanical injury, infection, and fluid loss. Two surfaces: Free surface: Exposed to air or fluid. Bottom surface: Attached to underlying tissues by a basement membrane, a dense layer of protein and polysaccharides. Slide 7: 1. Epithelial Tissue Can be classified based on two criteria: A. Number of layers: Simple: One layer. Stratified: Several layers B. Shape of cells: Squamous: Flat cells. Cuboidal: Cube shaped cells Columnar: Column shaped cells Example: Simple squamous epithelium Stratified columnar epithelium Slide 8: Epithelial Tissue Covers and Lines the Body and its Parts A. Simple squamous (Lung air sacs) D. Statified squamous (Lining esophagus) B. Simple cuboidal (Kidney tubes) C. Statified columnar (Lining intestine) Slide 9: 1. Epithelial Tissue Some epithelial tissues, such as mucous membranes, absorb and secrete chemical solutions. Mucous membranes: Digestive tract epithelium (mucous membranes) secretes mucus and digestive enzymes. Respiratory tract epithelium secretes mucous that helps trap dust particles before they reach the lungs. Slide 10: 2. Connective Tissue Relatively few cells surrounded by large amounts of nonliving material (matrix). Cells secrete the matrix, which can be solid, liquid, or gelatinous. Diverse functions. Mainly bind, support, and connect other tissues. Six types of connective tissue in humans: 1. Loose Connective Tissue: Most widespread connective tissue in vertebrates. Loose matrix with fibers, packing material. Attaches skin to muscles, binds and holds tissues and organs in place. 2. Adipose (fat): Pads and insulates body. Energy storage. Slide 11: Connective Tissue Binds and Provides Support A. Loose Connective Tissue B. Adipose Tissue C. Blood D. Fibrous Connective Tissue E. Cartilage F. Bone Slide 12: Types of connective tissue in humans (Continued): C. Blood: Fluid matrix (plasma) has water, salts, and proteins. Red and white blood cells. D. Fibrous Connective Tissue: Matrix of densely packed collagen fibers. Strong and nonelastic. Found in: Tendons: Attach muscles to bones. Ligaments: Attach bone to bone. E. Cartilage: Rubbery matrix with collagen fibers. Found on end of bones, nose, ears, and between vertebra. F. Bone: Supports the body of most vertebrates. Solid matrix of collagen fibers and calcium, phosphate, and magnesium salts. Bone is harder than cartilage, but not brittle because of collagen. Slide 13: 3. Muscle Tissue Most abundant type of tissue in most animals. Accounts for two-thirds (2/3) of human weight. Specialized for contraction. Made up of long cells that contract when stimulated by nerve impulses. Muscle cells have many microfilaments made up of actin and myosin. Muscle contraction accounts for much of energy consuming work in animals. Adults have a fixed number of muscle cells. Weight lifting doesn’t increase number of muscle cells, only their size. Slide 14: 3. Muscle Tissue There are three types of muscle tissue: A. Skeletal (striated) muscle : Attached to bones by tendons. Responsible for voluntary movements. B. Cardiac muscle: Forms contractile tissue of heart. Not under voluntary control. C. Smooth muscle: Found in walls of digestive tract, bladder, arteries, uterus, and many internal organs. Responsible for peristalsis and labor contractions. Contract more slowly than skeletal muscle, but can remain contracted longer. Not under voluntary control. Slide 15: A. Skeletal muscle B. Cardiac muscle C. Smooth muscle Three Types of Muscle Slide 16: 4. Nervous Tissue Senses stimuli and transmits signals from one part of the animal to another. Controls the activity of muscles and glands, and allows the animal to respond to its environment. Neuron: Nerve cell. Structural and functional unit of nervous tissue. Consists of: Cell body : Contains cell’s nucleus. Dendrite: Extension that conveys signals towards the cell body. Axon: Extension that transmits signals away from the cell body. Supporting cells: Nourish, protect, and insulate neurons. Slide 17: Nervous Tissue Forms a Communication Network Slide 18: Organs are made up of different tissues Organ: Several tissues that act as a unit and together perform one or more biological functions. Perform functions that component tissues can’t carry out alone. Example: The heart is an organ made up of: Muscle Tissue: Contraction Epithelial Tissue: Lines heart chambers to prevent leakage and provide a smooth surface. Connective Tissue: Makes heart elastic and strengthens its walls and valves. Nervous Tissue: Direct heart contractions. Organs are Made of Several Different Tissues : Organs are Made of Several Different Tissues Slide 20: Animals Regulate their Internal Environment Homeostasis: “Steady state”. Internal environment of animal remains fairly constant despite changes in the external environment. Control systems maintain internal conditions within a range in which life’s metabolic activities can occur. Homeostasis is a dynamic state resulting from changes in the outside environment and internal control mechanisms that oppose such changes. Slide 21: Homeostatic Mechanisms Counteract Changes in External Conditions Slide 22: Animals Regulate their Internal Environment Homeostasis: Maintained by negative feedback mechanisms. A change in one condition (e.g.: low body temperature), results is a response that counteracts that change (e.g.: shivering, etc.). Internal conditions regulated by negative feedback: Body temperature (Normal range: 97 - 100oF) Salt concentration pH Blood levels of sugar, calcium, oxygen, etc. Slide 23: Negative Feedback as Homeostatic Mechanism Slide 24: Body Temperature is Regulated by Homeostasis Slide 25: Major Organ Systems in Mammals Digestive system Respiratory system Circulatory system Cardiovascular Lymphatic and Immune system Excretory system Endocrine system Reproductive system Nervous system Muscular system Skeletal system Integumentary Slide 28: 1. Digestive System Components: Mouth, salivary glands, throat, esophagus, stomach, intestines, liver, gallbladder, pancreas, rectum, and anus. Functions: Ingest and mechanically break down food. Digest food: Stomach and small intestine mainly. Absorb nutrients and water. Eliminate waste. Homeostatic Roles: Supplies energy for life’s activities. Supplies building blocks for macromolecules Slide 29: Human Digestive System Obesity : Obesity Obesity is often diagnosed by using using a body mass index (BMI). BMI = w h 2 W = weight in kilograms H = height in meters Obesity in childhood is due to an increase in both the size and the # of adipocytes. Obesity defined as BMI > 30. Healthy weight as BMI between 19 – 25. Slide 34: 2. Respiratory System Components: Nose, throat, larynx, trachea, bronchi, and lungs. Functions: Exchange gases with the environment: Supplies blood with oxygen. Disposes of carbon dioxide (waste product from cellular respiration). Homeostatic Roles: Regulates blood pH. Regulates blood oxygen and carbon dioxide levels. Slide 35: Blood Transports Gases Between Lungs and Tissues Slide 36: Human Respiratory System Components: Nasal cavity, throat (pharynx), larynx (voice box), trachea, bronchi, alveoli, and lungs. Pathway of Inhaled Air: Nasal cavity Pharynx (Throat) Larynx (Voice Box) Trachea (Windpipe) Bronchi Bronchioles Alveoli (Site of gas exchange) Exhaled air follows reverse pathway. Slide 37: Blood Transports Gases Between Lungs and Tissues Slide 41: Human Respiratory System 1. Nasal cavity: Air enters nostrils, is filtered by hairs, warmed, humidified, and sampled for odors as it flows through a maze of spaces. 2. Pharynx (Throat): Intersection where pathway for air and food cross. Most of the time, the pathway for air is open, except when we swallow. 3. Larynx (Voice Box): Reinforced with cartilage. Contains vocal cords, which allow us to make sounds by voluntarily tensing muscles. High pitched sounds: Vocal cords are tense, vibrate fast. Low pitched sounds: Vocal cords are relaxed, vibrate slowly. More prominent in males (Adam’s apple). Slide 42: Human Respiratory System 4. Trachea (Windpipe): Rings of cartilage maintain shape of trachea, to prevent it from closing. Forks into two bronchi. 5. Bronchi (Sing. Bronchus): Each bronchus leads into a lung and branches into smaller and smaller bronchioles, resembling an inverted tree. 6. Bronchioles: Fine tubes that allow passage of air. Muscle layer constricts bronchioles. Epithelium of bronchioles is covered with cilia and mucus. Mucus traps dust and other particles. Ciliary Escalator: Cilia beat upwards and remove trapped particles from lower respiratory airways. Rate about 1 to 3 cm per hour. Pulmonary Function Tests : Pulmonary Function Tests Assessed by spirometry. Subject breathes into a closed system in which air is trapped within a bell floating in H20. The bell moves up when the subject exhales and down when the subject inhales. Spirogram : Spirogram Tidal volume: Amount of air expired with each breath. Vital capacity: The maximum amount of air that can be forcefully exhaled after maximum inhalation. Slide 47: Table 16.3 Terms Used to Describe Lung Volumes and Capacities Term Definition Lung Volumes The four nonoverlapping components of the total lung capacity Tidal volume The volume of gas inspired or expired in an unforced respiratory cycle Inspiratory reserve volume The maximum volume of gas that can be inspired during forced breathing in addition to tidal volume Expiratory reserve volume The maximum volume of gas that can be expired during forced breathing in addition to tidal volume Residual volume The volume of gas remaining in the lungs after a maximum expiration Lung Capacities Measurements that are the sum of two or more lung volumes Total lung capacity The total amount of gas in the lungs after a maximum inspiration Vital capacity The maximum amount of gas that can be expired after a maximum inspiration Inspiratory capacity The maximum amount of gas that can be inspired after a normal tidal expiration Functional residual capacity The amount of gas remaining in the lungs after a normal tidal expiration Restrictive and Obstructive Disorders : Restrictive and Obstructive Disorders Restrictive disorder: Vital capacity is reduced. FVC is normal. Obstructive disorder: VC is normal. FEV1 is reduced. Slide 49: Hemoglobin helps transport CO2 and buffer blood Hemoglobin is found in red blood cells Functions: Transports oxygen Transport carbon dioxide Helps buffer blood As carbon dioxide is picked up from tissues it is converted into carbonic acid: CO2 + H2O <-----> H2CO3 <----> H+ + HCO3 - Carbon Carbonic acid Carbonate ion dioxide Hemoglobin picks up most H + ions, so they don’t acidify the blood. Respiratory Acid-Base Balance : Respiratory Acid-Base Balance Ventilation normally adjusted to keep pace with metabolic rate. H2CO3 produced converted to CO2, and excreted by the lungs. H20 + C02 H2C03 H+ + HC03- Slide 54: Diseases of the Respiratory System Respiratory rate: 10 to 14 inhalations/minute. In one day, an average human: Breathes 20,000 times Inhales 35 pounds of air Most of us breathe in air that is heavily contaminated with solid particles, ozone, sulfur oxide, carbon monoxide, nitrogen oxides, and many other damaging chemicals. Breathing contaminated air can cause a number of diseases including asthma, bronchitis, emphysema, and lung cancer. Slide 55: Diseases of the Respiratory System Lung Cancer: Cancerous growth that invades and destroys lung tissue. Very high fatality rate. Symptoms include bloody sputum, persistent cough, difficulty breathing, chest pain, and repeated attacks of bronchitis or pneumonia. Causes: Smoking (50% of all cases) and pollution (radon, asbestos). Smokers are 10 times more likely to develop lung cancer than nonsmokers. Treatment: Surgery is most effective, but only 50% of all lung cancers are operable by time of detection. Other treatments include radiation and chemotherapy. Slide 57: 3. Cardiovascular System Components: Blood, heart, arteries, veins, and capillaries. Functions: Exchange gases with the respiratory system. Supplies tissues with oxygen. Removes carbon dioxide from tissues. Transports materials (nutrients, hormones, etc.) inside body. Defends against infection. Homeostatic Roles: Provides nutrients and removes waste materials from tissues. Regulates body temperature, water and ion balance. Slide 58: Human Cardiovascular System Slide 59: 1. Blood Average Blood Volume: 4 to 6 liters. Blood composition: 55% Plasma (fluid matrix of water, salts, proteins, etc.) 45% Cellular elements: Red Blood Cells (RBCs): 5-6 million RBCs/ml of blood. Contain hemoglobin which transport oxygen and CO2. White Blood Cells (WBCs): 5,000-10,000 WBCs/ml of blood. Play an essential role in immunity and defense. Include: Lymphocytes: T cells and B cells Macrophages (phagocytes) Granulocytes: Neutrophils, basophils, and eosinophils. Platelets: Cellular fragments. 250,000- 400,000/ml of blood. Important in blood clotting. Slide 60: Types of Blood Vessels A. Arteries and Arterioles: Carry blood away from heart to body. Have high pressure. Have thick muscular walls, which make them elastic and contractile. Vasoconstriction: Arteries contract: Reducing flow of blood into capillaries. Increasing blood pressure. Vasodilation: Arteries relax: Increasing blood flow into capillaries. Decreasing blood pressure. Slide 61: Types of Blood Vessels Capillaries: Only blood vessels whose walls are thin enough to permit gas exchange. Blood flows through capillaries relatively slowly, allowing sufficient time for diffusion or active transport of substances across walls. Only about 5 to 10% of capillaries have blood flowing through them. Only a few organs (brain and heart) always carry full load of blood. Blood flow to different organs is controlled by precapillary sphincters of smooth muscle. Slide 62: Types of Blood Vessels Veins and Venules: Collect blood from all tissues and organs and carry it back towards heart. Have low pressure and thin walls. Veins have small valves that prevent backflow of blood towards capillaries, especially when standing. If the valves cease to work properly, may result in: Varicose veins: Distended veins in thighs and legs. Hemorroids: Distended veins and inflammation of the rectal and anal areas. Red Blood Cell Antigens : Red Blood Cell Antigens ABO system: Major group of antigens of RBCs. Type A: Only A antigens present. Type B: Only B antigens present. Type AB: Both A and B antigens present. Type O: Neither A or B antigens present. Transfusion Reactions : Transfusion Reactions If blood types do not match, the recipient’s antibodies attach to donor’s RBCs and agglutinate. Type O: Universal donor. Recipient’s antibodies cannot agglutinate the donor’s RBCs. Type AB universal recipient: Lack the anti-A and anti-B antibodies. Cannot agglutinate donor’s RBCs. Rh Factor : Rh Factor Another group of antigens found on RBCs. Rh positive: Have these antigens. Rh negative: Do not have these antigens. Significant when Rh negative mother give birth to Rh positive baby. At birth, mother may become exposed to Rh positive blood of fetus. Mother at subsequent pregnancies may produce antibodies against the Rh factor. Slide 68: Heart Anatomical Features: Hollow muscular organ, about the size of a human fist. Weighs less than one pound (10 ounces). Rests on diaphragm, near middle of thoracic cavity. Wall is composed of cardiac muscle covered by connective tissue. Pericardium: Membrane that surrounds entire heart and contains a fluid which protects heart and decreases friction. Slide 69: Heart Heart Chambers: Heart is divided into four separate chambers. Both the left and the right side of the heart have a(an): Atrium (Plural atria): Smaller, superior chambers. Receive blood from veins. Ventricle: Larger, inferior chambers. Pump blood into arteries. Two sides of heart have different functions: Right side: Pumps oxygen poor blood. Left side: Pumps oxygen rich blood. Slide 72: Pacemaker (Sinoatrial node): Specialized structure that sends electrical impulses that causes both atria and ventricles to contract. Slide 73: Heart Heart Valves: Heart has several valves made of connective tissue, that prevent backflow of blood as it circulates. Atrioventricular (AV) Valves: Close between atria and ventricles Right AV Valve: Connects right atrium to the right ventricle. Left AV Valve: Connects left atrium to the left ventricle. Semilunar Valves: Close as blood leaves the ventricles and enters the arteries. Heart murmur: Rushing, gurgling sound created by backflow of blood due to damaged or imperfect heart valves. Fairly common (10% of healthy population). Most are asymptomatic. Slide 74: Heart Beat Average 70 beats per minute. 100,000 beats every day. Cardiac cycle about every 0.8 sec. Diastole: Heart relaxes and blood flows into chambers (0.4 sec). Systole: Heart contracts. First atria (0.1 sec) Then ventricles (0.3 sec) Pumps about 8000 liters of blood/day. Pacemaker (Sinoatrial node): Controls heart rate. Regulated by nervous and endocrine systems. Two heart beat sounds (“Lub-dupp”): First sound: Ventricles contract, AV valves close. Second sound: Heart relaxes, semilunar valves are closing. Pulse: Arteries expand and contract with each heartbeat. Slide 76: Pacemaker Controls Cardiac Rhythm Slide 79: Blood Pressure Pressure is highest in arteries; lowest in veins. “Blood pressure” usually refers to arterial pressure. Usually measured at brachial artery in arm. Two measurements: Systolic Blood Pressure: During heart contraction. Normal systolic pressure is about 120 mm Hg. (Range: 110-140 mm Hg). Diastolic Blood Pressure: During heart relaxation. Normal diastolic pressure is about 80 mm Hg. (Range: 70-90 mm Hg) Slide 81: Blood Pathway in Body Right Side of Heart: Right atrium receives oxygen poor blood from body. Right ventricle pumps oxygen poor blood to lungs. Left Side of Heart: Left atrium receives oxygenated blood from lungs. Left ventricle pumps oxygenated blood to body. Blood Pathway: Veins Vena cava Right atrium Right AV Valve (Tricuspid) Right ventricle Pulmonary Semilunar Valve Pulmonary arteries Lungs Pulmonary veins Left atrium Left AV Valve (Bicuspid or Mitral Valve) Left ventricle Aortic Semilunar Valve Aorta Arteries Capillaries Veins Slide 87: Cardiovascular Disease Number one cause of death in the U.S. and industrialized nations. Includes hypertension, strokes, heart attacks, and congestive heart failure. Most often caused by complications of: Arteriosclerosis: A condition in which arteries become blocked by calcium and lipid deposits (plaque), losing their elasticity. Slide 88: Heart Attack (Myocardial infarction-MI) Sudden decrease in blood supply to the heart, due to a clot or plaque in arteries. Death of cardiac muscle resulting in insufficient blood supply to rest of body. Heart may stop beating altogether or suffer permanent damage. Over 7.9 Million heart attacks every year in U.S. (2004) Leading cause of death and disability 60% had no previous symptoms. 25% are not recognized when they occur. Heart Attacks are Caused by Blocked Coronary Arteries : Heart Attacks are Caused by Blocked Coronary Arteries Slide 90: Heart Attack (Myocardial infarction) Symptoms: Chest pain, pressure, or tightness, sweating, nausea, shortness of breath, dizziness, and fainting. Risk factors: Smoking High blood pressure High cholesterol High LDLs (low density lipoproteins) Diabetes Male gender Emotional stress Obesity Heredity Sedentary lifestyle Slide 96: 4. Lymphatic and Immune System Components: Lymph, lymphatic vessels, bone marrow, thymus, spleen, and lymph nodes. Functions: Defends against infection: bacteria, fungi, viruses, etc. Destruction of cancer and foreign cells. Synthesis of antibodies and other immune molecules. Synthesis of white blood cells. Homeostatic Role: Returns fluid and proteins that have leaked from blood capillaries into tissues. Up to 4 liters of fluid every day. Fluid returned near heart/venae cavae. Slide 97: Lymphatic and Immune Systems Slide 98: Introduction Resistance: Ability to ward off disease. Nonspecific Resistance: Defenses that protect against all pathogens. Specific Resistance: Protection against specific pathogens. Susceptibility: Vulnerability or lack of resistance. Slide 99: Protection Against Invading Pathogens 1. First Line of Defense: Non-specific natural barriers which restrict entry of pathogen. Examples: Skin and mucous membranes. 2. Second Line of Defense: Non-specific defenses that provide rapid local response to pathogen after it has entered body. Examples: Fever, phagocytes (macrophages and neutrophils), inflammation, and interferon. 3. Third line of defense: Antigen-specific immune responses, specifically target and attack invaders that get past first two lines of defense. Examples: Antibodies and lymphocytes. Defenses Against Infection : Defenses Against Infection Slide 101: The Immune Response Destroys Specific Invaders Antigen: Molecule that elicits an immune response. “Antibody generating”. Microbial antigens: Viral capsid, bacterial cell wall, etc. Nonmicrobial antigens: Pollen, latex, food, etc. Antibody: Protein found in blood plasma that attaches to antigen and helps counteract its effects. Vaccination or Immunization: Process in which harmless forms of antigen or pathogen are introduced into body to provoke an immune response. Diseases Caused by the Immune System : Diseases Caused by the Immune System Ability of immune system to tolerate self-antigens while it identifies and attacks foreign antigens that can be deranged. Diseases caused by the immune system can be grouped into 3 categories: Autoimmune disease. Immune complex diseases. Allergy or hypersensitivity. Autoimmunity : Autoimmunity Those produced by failure in the immune system to recognize and tolerate self-antigens. Failure due to: An antigen that does not normally circulate in the blood may be exposed to the immune system. Thyroglobulin. A self-antigen that is otherwise tolerated may be altered by combining with a foreign hapten. Thrombocytopenia. Autoimmunity : Autoimmunity Antibodies may be produced that are directed against other antibodies. Rheumatoid arthritis. Antibodies produced against foreign antigens may cross-react with self-antigens. Rheumatic fever. Self-antigens may be presented to the helper T cells together with class-2 MHC molecules. Type I diabetes. Slide 106: 5. Excretory (Urinary) System Components: Kidneys, bladder, urethra, and associated ducts. Functions: Kidneys remove nitrogen containing waste from blood. Urine with waste is temporarily stored in bladder. Excretion of urine. Homeostatic Role: Regulates water levels in body. Removes excess water Helps conserve water Slide 107: Human Excretory System Renal Acid-Base Regulation : Renal Acid-Base Regulation Kidneys help regulate blood pH by excreting H+ and reabsorbing HC03-. Most of the H+ secretion occurs across the walls of the PCT in exchange for Na+. Antiport mechanism. Normal urine normally is slightly acidic because the kidneys reabsorb almost all HC03- and excrete H+. Returns blood pH back to normal range. Reabsorption of HCO3- : Reabsorption of HCO3- Apical membranes are impermeable to HCO3-. Reabsorption is indirect. HCO3- combines with H+ to form H2C03, which is catalyzed by carbonic anhydrase (ca) located in the apical cell membrane of PCT. As [C02] increases in the filtrate, ca forms H2C03. H2C03 dissociates to HCO3- and H+. Shunt HCO3- generated within tubule cell to peritubular capillary. Urinary Buffers : Urinary Buffers Nephron cannot produce a urine pH < 4.5. IN order to excrete more H+, the acid must be buffered. H+ secreted into the urine tubule and combines with HPO4-2 or NH3. HPO4-2 + H+ H2PO4-2 NH3 + H+ NH4+ Diuretics : Diuretics Increase urine volume excreted. Increase the proportion of glomerular filtrate that is excreted as urine. Loop diuretics: Inhibit NaCl transport out of the ascending limb of the LH. Thiazide diuretics: Inhibit NaCl reabsorption in the DCT. Ca inhibitors: Prevent H20 reabsorption when HC03- is reabsorbed. Osmotic diuretics: Increase osmotic pressure of filtrate. Slide 115: 6. Endocrine System Components: Pituitary, adrenal, thyroid, thymus, pancreas, ovaries, testes, and other ductless glands. Functions: Produce hormones that regulate: Blood chemistry: Levels of sugars, minerals, etc. Reproduction Growth Metabolism Digestion Homeostatic Role: With nervous system, regulates metabolism and blood chemistry. Slide 116: Human Endocrine System Hormones : Hormones Regulatory molecules secreted into the blood or lymph by endocrine glands. Lack ducts. Carry hormone to target tissue where it produces its effects. Posterior Pituitary : Also called the neurohypophysis. Formed by downgrowth of the brain during fetal development. Is in contact with the infundibulum. Nerve fibers extend through the infundibulum. Posterior Pituitary Hypothalamic Control of Posterior Pituitary : Hypothalamic Control of Posterior Pituitary Hypothalamus produces: ADH: supraoptic nuclei. Oxytocin: paraventricular nuclei. Hormones transported along the hypothalamo-hypophyseal tract. Stored in posterior pituitary. Release controlled by neuroendocrine reflexes. Anterior Pituitary : Master gland (also called adenohypophysis). Derived from a pouch of epithelial tissue that migrates upward from the mouth. Consists of 2 parts: Pars distalis: anterior pituitary. Pars tuberalis: thin extension in contact with the infundibulum. Anterior Pituitary Anterior Pituitary : Trophic effects: Health of the target glands, depends upon stimulation by anterior pituitary for growth. High plasma hormone concentration causes target organ to hypertrophy. Low plasma hormone concentration causes target organ to atrophy. Anterior Pituitary Growth Hormone (GH) - Somatotrophic Hormone (STH) : Growth Hormone (GH) - Somatotrophic Hormone (STH) Increases Growth and Maintenance of Organs by: stimulating protein anabolism promotes fat catabolism (use of fat rather than sugars for energy) Abnormal Secretions of STH Giantism -- hypersecretion during childhood (before epiphyseal plates close) Acromegaly -- hypersecretion during adulthood Dwarfism -- hyposecretion during childhood Cachexia (Simmond's Disease) - hyposecretion during adulthood causes premature aging and atrophy of organs Thyroid Hormones : Thyroid Hormones Thyroid gland located just below the larynx. Thyroid is the largest of the pure endocrine glands. Follicular cells secrete thyroxine. Parafollicular cells secrete calcitonin. Parathyroid Hormone : Parathyroid Hormone Parathyroid glands embedded in the lateral lobes of the thyroid gland. Only hormone secreted by the parathyroid glands. Single most important hormone in the control of plasma Ca++ concentration. Stimulated by decreased plasma Ca++ concentration. Adrenal Glands : Adrenal Glands Paired organs that cap the kidneys. Each gland consists of an outer cortex and inner medulla. Adrenal medulla: Derived from embryonic neural crest ectoderm (sympathetic ganglia). Synthesizes and secretes: Catecholamines (mainly epinephrine but some norepinephrine). Adrenal Glands : Adrenal Glands Adrenal cortex: Does not receive neural innervation. Must be stimulated hormonally. Consists of 3 zones: Zona glomerulosa: Aldosterone: regulate Na+ and K+ balance. Zona fasciculata: Cortisol: regulate glucose metabolism. Zona reticularis: Androstenedione and DHEA: supplement sex steroids. Adrenal Medulla : Adrenal Medulla Innervated by sympathetic nerve fibers. Increase respiratory rate. Increase heart rate, cardiac output; and vasoconstrict blood vessels, thus increasing venous return. Stimulate glycogenolysis. Stimulate lipolysis. Pancreas : Pancreas Endocrine portion consists of islets of Langerhans. Alpha cells secrete glucagon. Stimulus is decrease in plasma glucose concentrations. Stimulates lipolysis. Beta cells secrete insulin. Stimulus is increase in plasma glucose concentrations. Promotes entry of glucose into cells. Diabetes Mellitus : Diabetes Mellitus Type I (insulin-dependent) diabetes Pancreas does not produce insulin T cells destroy pancreatic islets Needs daily insulin injections Type II (noninsulin-dependent) diabetes Most common type of diabetes Obesity and inactivity are risk factors Insulin is produced, but there is decreased response to the insulin perhaps because of a lack or deficiency in insulin receptors. Consequences: May lead to blindness, kidney disease, & circulatory disorders like atherosclerosis, heart disease, and stroke. Lack of circulation may also cause gangrene. Diabetic coma may also result and there is an increased risk of having a stillborn child. Slide 139: 7. Reproductive System Components: Female: Ovaries, oviduct, uterus, vagina, and associated structures Male: Testes, seminal vesicles, prostate, urethra, penis, and associated structures. Functions: Only organ system that is not essential for individual survival. Continuation of species. Gamete formation (eggs and sperm cells). Homeostatic Role: Maintains secondary sexual characteristics. Slide 140: Reproductive System of Humans Reproductive Functions of Male: Produces sperm Delivers sperm to female reproductive tract All of these processes are regulated and coordinated by hormones secreted by: Hypothalamus Pituitary gland (anterior portion) Testes (Sing. Testis) Slide 141: Male Reproductive System Slide 142: Major Organs of Male Reproductive System: Testes: Paired male gonads. Produce sperm through spermatogenesis, which produces four sperm cells of equal size. Spermatogenesis occurs in a vast system of hollow tubes called seminiferous tubules. Each mature sperm has a head, a midpiece, and a flagellum. Sperm head has an acrosome, which produces enzymes that help it penetrate the egg. Human sperm cannot develop at body temperature. Testicles descend from abdominal cavity into scrotum, a skin covered sac, about two months before birth. Undescended testicles (cryptorchidism) may cause infertility. Slide 143: Reproductive System of Humans Major Organs of Male Reproductive System: Epididymus: Large coiled tube (23 ft long) that surrounds testes. Stores sperm while they develop fertilizing ability and motility (about 20 days). During ejaculation, sperm cells are propelled from epididymus. Vas Deferens: Long muscular ducts from scrotum to back of bladder. During ejaculation, the sperm pass from epididymus into these two ducts. Vasectomy: Each vas deferens is cut to prevent sperm from entering urethra. Slide 144: Reproductive System of Humans Major Organs of Male Reproductive System: Ejaculatory Duct: Short duct after two vas deferens ducts unite. Urethra: Deliver sperm to the exterior. In males, urine and sperm pass through the urethra. Females have a separate urethra from the reproductive system. Slide 145: Reproductive System of Humans Major Organs of Male Reproductive System: Accessory Glands: Produce semen. Functions of semen: Activate sperm cells Provide nutrients for motility Counteract acidity of vagina and male urethra Stimulate contractions of female reproductive tract Antimicrobial action Ejaculation volume 4 to 5 ml. One ejaculation has 50-500 million sperm cells Sperm cells account for less than 5% of semen volume. Secretions from 3 different accessory glands make up the rest of the volume: Seminal vesicles (2), prostate, and bulbourethral glands (2). Slide 146: Major Organs of Male Reproductive System: Accessory Glands: A. Seminal vesicles (2): Secrete fluid that nourishes sperm. Contribute about 60% of semen volume. Thick, clear, alkaline fluid. Contains: Fructose: Provides energy for sperm motility. Prostaglandins: Stimulate smooth muscle contractions of female and male reproductive tracts. Fibrinogen: Forms temporary clot in vagina. Sperm cells become highly motile when mixed with this fluid. Slide 147: Accessory Glands: B. Prostate gland: Produces a thin milky secretion. Largest of semen secreting glands. Contributes 30% of semen volume. Produces an antibiotic that may prevent urinary tract infections in men. Benign (noncancerous) prostate enlargement is common among older men. 50% of men over 40. Almost all men over 70. Prostate cancer is the second leading cause of cancer and cancer deaths in men. Over 330,000 new cases/year and 40,000 deaths. Average age at diagnosis: 72 Detected by blood test or digital rectal exam. Treated surgically or with drugs to reduce prostate size or activity. Slide 148: Major Organs of Male Reproductive System: Accesory Glands: C. Bulbourethral glands (2): Release a mucous secretion that lubricates penis and facilitates its entry into vagina. Pair of small glands below the prostate. Contribute 5-10% of semen volume. Before ejaculation secrete a clear mucus that neutralizes acid from remaining urine in urethra. Bulbourethral fluid also carries some sperm that is released before ejaculation. One cause of high failure rate of withdrawal method. Slide 149: Major Organs of Male Reproductive System: Penis: Copulatory organ that delivers sperm to female body. Composed of three cylinders of erectile tissue. During sexual arousal, the penis fills with blood from the arteries. Erection is essential for penetration. Impotence is the inability to maintain an erection. May be caused by alcohol, drugs, illness, and/or emotional problems. Viagra acts by relaxing smooth muscle of penis blood vessels, allowing blood to enter erectile tissue. Penis structure: Shaft: Long cylinder with thick skin. Glans: Enlarged tip of penis. Thin skin, covered by prepuce or foreskin. Slide 150: Reproductive System of Humans Reproductive Functions of Female: Produces eggs (ova) Receives sperm Incubates and nourishes the embryo and fetus Gives birth Produces milk for young All of these processes are regulated and coordinated by hormones secreted by: Hypothalamus Pituitary gland (anterior portion) Ovaries Slide 151: Female Reproductive System Slide 152: Reproductive System of Humans Major Organs of Female Reproductive System: Ovaries: Produce ova (oogenesis) and sex hormones. Size and shape of large almonds. Located close to lateral walls of pelvic cavity and held in place by connective tissue. Mainly connective tissue containing scattered eggs (ova) in different stages of development. Follicles: A single egg with surrounding cells that nourish and protect it. Women are born with all of their follicles (40,000 to 400,000). Only a fraction of follicles release eggs during a woman’s reproductive life. Slide 153: Female Reproductive System: Ovulation & Oogenesis: After puberty, each month one immature egg (oocyte), is released from ovary. Each follicle contains a primary oocyte, arrested in prophase I of meiosis. Pituitary hormones FSH (follicle stimulating hormone) and LH (luteinizing hormone) cause a follicle to enlarge and complete meiosis I. One large cell (secondary oocyte) and a tiny cell (polar body) are produced. LH (luteinizing hormone) causes the secondary oocyte to be released by the ovary during ovulation. Oocyte will not finish meiotic division, until fertilized. In the end, one large ovum (egg) and 3 small polar bodies are made from oogenesis. Slide 154: Major Organs of Female Reproductive System: Oviducts (Fallopian Tubes): Transport the egg from the ovary to the uterus. Peristalsis of smooth muscle in oviduct and beating of cilia, help the egg move along. Fertilization occurs in the first third of oviduct. Scarring of oviducts is a common consequence of sexually transmitted diseases: chlamydia and gonorrhea. Ectopic Pregnancy: Fertilized egg does not reach the uterus. Usually starts to develop in oviduct. Usually due to a blocked oviduct. Occurs in 1% of all pregnancies in the U.S. Must be surgically removed. May cause death and severe hemorrhage. Slide 155: Reproductive System of Humans Major Organs of Female Reproductive System: Uterus: Incubates the embryo/fetus. Size of a fist, in center of pelvic cavity. Oviducts open into upper corners of uterus. Has thick walls of smooth muscle (myometrium) responsible for uterine contractions and cramps. Endometrium: Inner mucous lining, which thickens each month in preparation for pregnancy. If fertilization does not occur, endometrium breaks down and is discharged during menstruation. If fertilization occurs, the egg implants in the endometrium which supports its growth until the placenta develops. Slide 156: Reproductive System of Humans Major Organs of Female Reproductive System: Cervix: Lower portion of the uterus, which projects into the vagina. Pap smear: Examination of cervical tissue to detect abnormalities. Recommended yearly. Cervical cancer: Most cases caused by a viral infection with human papillomavirus. Women are infected through intercourse with asymptomatic male. Takes about 20 to 30 years to develop. Men don’t appear to be affected. Slide 157: Reproductive System of Humans Major Organs of Female Reproductive System: Vagina: Thin walled, muscular chamber. Receives the sperm and penis Acid pH kills bacteria and sperm cells Part of birth canal Vulva: External structures. Clitoris: Equivalent to male penis. Labia minora: Skin folds that border vaginal opening. Labia majora: Protect entire genital region. Hymen: Ring of tissue that forms a border around vaginal entrance. No known function. Bartholin’s gland: Secrete lubricating fluid during sexual arousal. Breasts: Lactation Slide 160: 8. Nervous System Components: Brain, spinal cord, nerves, sense organs, and associated structures. Functions: Works with endocrine system to coordinate body activities. Integrates and processes information from sense organs. Sends signals (instructions) to muscles and glands. Responds to internal stimuli. Homeostatic Role: Regulates most organ activities along with endocrine system. Slide 161: Human Nervous System Slide 162: Functions of Nervous Tissue 1. Sensory Input: Conduction of signals from sensory organs (eyes, ears, nose, skin, etc.) to information processing centers (brain and spinal cord). 2. Integration: Interpretation of sensory signals and development of a response. Occurs in brain and spinal cord. 3. Motor Output: Conduction of signals from brain or spinal cord to effector organs (muscles or glands). Controls the activity of muscles and glands, and allows the animal to respond to its environment. Slide 163: Nervous System Allows Us to Respond to Our Environment Slide 164: Cells of Nervous Tissue 1. Neuron: Nerve cell. Structural and functional unit of nervous tissue. Carry signals from one part of the body to another. 2. Supporting cells: Nourish, protect, and insulate neurons. There are roughly 50 supporting cells for every neuron. In humans, Schwann cells wrap around the axons of neurons, forming a myelin sheath that is essential for transmission of nerve impulses. Slide 165: Neuron Structure Cell body : Contains nucleus and most organelles. Dendrites: Extensions that convey signals towards the cell body. Short, numerous, and highly branched Axon: Extension that transmits signals away from the cell body to another neuron or effector cell. Usually a long single fiber. Axon is covered by a myelin sheath made up of many Schwann cells that are separated by small spaces (Nodes of Ranvier). Slide 166: Structure of the Neuron Slide 167: Neuron Structure Myelin sheath and nodes of Ranvier greatly speed up nerve impulses, which jump down axon from node to node. Speed of signal Myelinated axon 100 meters/second Unmyelinated axon 5 meters/second Multiple sclerosis: A disease in which a person’s immune system destroys the myelin sheaths on their neurons. Loss of muscle control Impaired brain function Death Slide 168: What is a Nerve Impulse? An electrical signal that depends on the flow of ions across the neuron plasma membrane. Resting Potential: A neuron at rest has a net negative charge (-70 mV, equivalent to 5% of the voltage in AA battery). The net negative charge is due to different ion concentrations across the neuron membrane. Slide 170: What is a Nerve Impulse? An electrical signal that depends on the flow of ions across the neuron plasma membrane. Action Potential: When a neuron is stimulated above a certain threshold, this causes: 1. Depolarization: An influx of positive ions (Na+) into the cell, caused by the opening of sodium channels. The inside of the cell becomes positively charged for a brief moment (1-2 milliseconds). 2. Repolarization: After a few milliseconds, the neuron allows other positive ions (K+) to leave the cell so the inside of the cell becomes negatively charged once again. Resting Potential is Caused by Differences in Ion Concentrations Across Neuron Membrane : Resting Potential is Caused by Differences in Ion Concentrations Across Neuron Membrane Action Potential Requires Stimulus Above a Certain Threshold : Action Potential Requires Stimulus Above a Certain Threshold Nerve Impulses are Caused by Action Potentials : Nerve Impulses are Caused by Action Potentials Slide 176: Neurons Communicate at Synapses Synapse: Junction between two neurons or a neuron and an effector cell (muscle or gland). There are two types of synapses: 1. Electrical Synapse: Found in heart and digestive tract of human body. Action potentials pass directly from one neuron to another. 2. Chemical Synapse: Found in CNS, muscles, and most other organs. Require neurotransmitters: Chemicals that convey messages from one neuron to another. Transmitting neuron releases neurotransmitters which cross synapse and cause an action potential in the receiving neuron. Synapse : Synapse Functional connection between a neuron and another cell. Different types of synapses involve: Axonodendritic: Axon of one neuron and dendrite of another neuron. Axosomatic: Axon of one neuron and cell body of another neuron. Axoaxonic: Axon of 1 neuron and axon of another neuron. Transmission in one direction only. Chemical Synapses Use Neurotransmitters : Chemical Synapses Use Neurotransmitters Diseases of the Nervous System : Diseases of the Nervous System I. Alzheimer’s Disease Most common form of dementia in U.S. Unknown cause, probably both genetic and environmental factors are important. No effective treatment Certain diagnosis is usually only possible through discovery of typical brain lesions during autopsy. Usually affects elderly: Over 4 million cases in U.S. 10% of those over 65 Almost half of those over 85 Symptoms progress over time. Three stages: Mild Stage: Forgetfulness, minor disorientation, mild personality changes, depression, difficulty in finding right words during conversation, and performing arithmetic calculations (e.g.: balancing checkbook). Diseases of the Nervous System : Diseases of the Nervous System I. Alzheimer’s Disease (Continued) Stages of Alzheimer’s Disease: Moderate Stage: Noticeable memory loss, difficulty performing everyday tasks (bathing, dressing, cooking, driving, operating appliances), may wander off, confuse day and night, fails to recognize acquaintances and distant relatives. Severe Stage: Very limited speech (less than 12 words), eventually becomes mute and uncomprehending, loses all self-care ability, can’t recognize closest relatives, friends, or caregivers, becomes incontinent, progressively loses ability to walk, stand, sit up, smile, and hold head up. Many patients die from complications like pneumonia. Brain Atrophy in Alzheimer’s Disease : Brain Atrophy in Alzheimer’s Disease Definite diagnosis of Alzheimer’s usually requires post-mortem brain examination. Notice pronounced atrophy with wide sulci (grooves) in frontal and parietal regions. Source: www-medlib.med.utah.edu/WebPath/CNSHTML Slide 188: 9. Muscular System Components: Skeletal muscles. Functions: Skeletal muscle contraction allows for voluntary movement: Movement and locomotion. Mechanical work: Lifting, pulling, pushing objects. Communication: Body language and facial expression. Homeostatic Role: Allows animals to respond to and control their environment. Slide 189: Muscular System: Skeletal Muscle Allows Voluntary Movement Slide 197: 10. Skeletal System Components: Bones, ligaments, and cartilage. Functions: Along with muscular system: Movement and locomotion. Mechanical work: Lifting, pulling, pushing objects. Body support. Protection of delicate internal organs (brain, heart, lungs, etc.) Calcium storage Homeostatic Role: Helps maintain constant blood calcium levels. Slide 198: Skeletal System: Protection, Movement, & Support Slide 201: 11. Integumentary System Components: Hair, skin, and nails. Functions: Protects the body from: Infection: Barrier to microbes. Mechanical injury Excessive heat or cold: Thermoregulation Water loss Communication: Receives stimuli from environment Gives out subtle signals (blushing, etc.). Homeostatic Role: Helps maintain constant body temperature. Slide 202: Integumentary System: Skin, Nails, & Hair Slide 204: Organ systems must be coordinated for animal to survive Organ systems interact with one another in order to maintain fairly stable conditions (homeostasis) that are required for life. Example: Interactions between: Respiratory Circulatory Digestive Slide 205: Relationships Between Several Major Organ Systems