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Lectures for Human Body Systems: Jan 10th: Childhood health, weight and height charts, immunizations Childhood is an interesting time regarding health. Height vs. Weight growth charts. Immunizations, how they work, immunization schedule. Hep B – vomiting., jaundice, cirrhosis, liver cancer, death Diphtheria – sore throat, fever, swollen neck, Tetanus – muscle locking Pertussis – whooping cough, last for 6 weeks, occasional death Haemophilus influenza B – bacteremia, meningitis, cellulitis, opportunistic pathogens Polio – 1% CNS muscle weakness paralysis, summer time epidemics, paralysis, sparked race for vaccine Pneumococcal – pneumonia, meningitis, enteritis, sepsis, cellulitis, pericarditis Rotavirus – severe diarrhea in infants and children Measles – respiratory, 90% infectivity, 9 – 12 day incubation, general flu-like symptoms Mumps – painful swelling of salivary glands and testicles, can lead to infertility in older males Rubella – German measles, dangerous to pregnant women, babies born with major birth defects Varicella – chicken pox, shingles Human Papillomavirus – causes cervical cancer in females Meningitis – inflammation of the meninges of the brain, neck stiffness, light and sound intolerance Herd Immunity Many children’s immune systems are still developing. When they begin to be exposed to daycare and school they often get exposed to different diseases. ARTICLE – The Dirt on Germs Discussion, of reading. Jan 14th: Milestones 9 – 20 9 – 12 years: Physical growth rate increases, sex characteristics begin to appear, menstruation, breast development, male voice deepens, hair growth, begin to place higher importance on peer groups Begin to exhibit insecurity and shyness Need to be listened to, allowed to express themselves, positive responses, start of social acceptance, need to learn acceptable behavior, need LOTS of positive reinforcement or will shut down 13 – 18 years: Teenagers, between childhood and adulthood, strive for independence, experience puberty, increased hormone production, emotionality, Adolescents, need to have people listen and reflect back to them, allows teens to hear what they are thinking, gain understanding of themselves, respect privacy, Question personal behavior and choices, always ask how it relates to their personal health and well being, impulsivity, often reckless, 18 – 20 years: Become independent, adults, seek place in society Jan 22nd: Effect of aging on body systems Aging begins at birth; people vary greatly in how they age, choices, exposure Nervous System: Reduction in nerve cells and blood flow Memory loss and loss of problem solving ability Vision – harder to see distance and small, 20% more light needed, eyes take longer to adjust to changes in light, cataracts are clouding of the transparent lens, glaucoma is intraocular pressure that can cause damage to the optic disc and hardening of the eyeball Hearing – changes become noticeable in the 60’s, high frequency detection is poor, mumbling and soft speaking common Smell – less likely to smell gas, spoiled food, body odor Taste – may require more salt or sugar, taste buds decline by 50% Touch – temperature sensitivity, response to stimulus depressed, often cold due to subcutaneous fat loss Musculoskeletal System: Osteoarthritis is an inflammation of joints Osteoporosis is brittle bones cause by Calcium loss, most common in Caucasian women after menopause; proper diet and exercise can forestall symptoms, Reduced stamina, reduced muscle tone Respiratory and Circulatory Systems: Lungs become less elastic, oxygen exchange more difficult Heart less efficient, vessels build up clogs, high blood pressure Congestive heart failure – inability of heart to supply body with oxygen, smoking, obesity, age Cardiac arrhythmias – any irregular heartbeat, pacemaker, death, cardiac arrest Ischemic heart disease – lack of blood to heart muscle, most common cause of death in West Hypertensive heart disease – high blood pressure, heart works harder to push blood Gastrointestinal System: Constipation is common; peristalsis is weakened in the intestines May not take in enough water or fiber Loss of teeth may interfere with chewing Liver loses up to 20% of its weight Liver becomes less effective at metabolizing drugs Urinary System: Bladder holds less May cause urgent and frequent need to urinate Bladder infection caused by retention – inability to completely empty bladder Prostate gland swelling pinches off male urethra Incontinence may occur as external urinary sphincter control is lost Integumentary System: Dry skin, thinning hair, less adipose padding and thermal insulation Jan 31st: Anatomy of the circulatory system Arteries Veins Capillaries Heart = center of the cardiovascular system Cardiology = study of the normal heart and diseases of the heart Pericardium Outer fibrous pericardium (tough, dense irreg. CT) Inner serous pericardium = parietal layer (outer) + visceral (inner) layer Space btwn. the 2 serous membranes = pericardial cavity; filled with pericardial fluid; Physiology: reduces friction pericarditis = inflammation of the pericardium Chambers of the Heart 2 upper atria RA and LA are separated by the interatrial septum atrial walls are thin; only have to “push” blood into the ventricles 2 lower ventricles RV and LV are separated by the interventricular septum ventricular walls thicker than atrial walls; must pump blood further RV pumps blood into the Pulmonary circulation; low pressure LV pumps blood into the Systemic circulation; much higher P Valves of the Heart Valves are made of dense CT, covered by endothelium Valves prevent the backflow of blood into the heart; one-way blood flow Atrioventricular (AV) valves: btwn. RA and RV = tricuspid valve = 3 “flaps” or cusps btwn. LA and LV = bicuspid valve = 2 cusps; called mitral valve chordae tendineae = tiny “tendons” which keep the “flaps” of these valves pointing in the direction of blood flow papillary muscles “pull” on the chordae tendineae when the ventricles contract Semilunar valves Pulmonary semilunar valve = btwn. RV and pulmonary trunk Aortic semilunar valve = btwn. LV and aorta Rheumatic Fever = complication of group A Strep infection can lead to damage of the heart valves, esp. the bicuspid & aortic SL Overview of Blood Flow Systemic circulation, Cardiac cycle, Pulmonary circulation, Cardiac cycle, Heart Blood Supply = Coronary (Cardiac) Circulation Angina pectoris = severe pain in the area with reduced blood supply Myocardial infarction = heart attack; death of an area of the myocardium due to ischemia Feb 5th: Blood typing lecture ABO blood group system A and B Ag’s on the RBC’s determine a person’s blood type “universal” donor = group O “universal” recipient = group AB Rh blood group (type) system Rh-positive = contains the Rh-Ag on RBC’s Rh-negative = no D-Ag on RBC’s Actually MUCH more complicated (CcDEe) Only produce anti-Rh Ab’s AFTER your body “sees” these Ag’s, from a blood trxn. or pregnancy (NOT like the ABO system) If mother is Rh(neg) and baby is Rh(+), mother may produce Ab’s against the baby’s D-Ag First baby is usually NOT affected; second Rh(+) baby, etc. Can prevent by administering RhoGam within 72 hrs. after delivering each Rh(+) baby (RhoGam = anti-D) Punnett Square Practice Feb 12th: Blood cells Hematology = study of blood, blood-forming tissues, & disorders of these Fxns. of blood: Blood transports: O2 from lungs to body cells nutrients (glucose) from GI tract to body cells hormones from endocrine glands/tissues to body cells waste products from body cells to lungs (CO2), kidneys (urea, creatinine, etc.), sweat glands (electrolytes), liver, etc. heat from body cells to the surface of the body Blood regulates: pH (contains buffers; pH 7.35 - 7.45) Body Temp. (vasoconstriction / vasodilation) (blood temp. is 38oC) water content of cells (OsmP) Blood protects: Coagulation protects against blood loss WBC’s protect against foreign invaders TBV = 4-6 L / 8% of body wt. (males 5-6 L ; females 4-5 L) Components of Blood Plasma = liquid portion of blood (55%) Other solutes: electrolytes (Na, K, Cl, HCO3, PO4’s, etc.) nutrients (glucose, etc.) hormones (some are proteins) gases (O2, CO2) waste products (urea, NH3, creatinine, uric acid, bilirubin, etc.) Formed Elements of the blood (45%) = Hct Erythrocytes ~5 million / µL Thrombocytes 200,000 - 400,000 / µL Leukocytes 5,000 - 10,000 / µL Neutrophils Eosinophils Basophils Lymphocytes (B & T cells) Monocytes (RBC : WBC ~700:1) Formation of Blood Cells = Hematopoiesis Hematopoietic Stem Cells, Stem cells are found in the red bone marrow (myeloid tissue) Erythrocytes, Biconcave discs, no nucleus, no organelles, non-mitotic, contain RBC’s live about 120 days; pl-mb “wears out” from squeezing thru cap’s Anemia = less than normal amt. of Hgb or RBC’s Polycythemia = greater than normal amt. of Hgb or RBC’s When each RBC gets worn-out, it gets phagocytized by macrophages, usually in the spleen Hgb inside the RBC gets “recycled” Eosinophils = parasites, worms, allergic reactions Basophils = allergic reaction or leukemia, involved in inflammatory response Neutrophils = bacterial infection Monocytes = very large, can leave blood, becomes macrophage, fungal infections Lymphocytes = viral infections, transfusion reactions, tissue rejection, allergies Thrombocytes, Lifespan 5 - 9 days, hemostasis = stoppage of bleeding Hemorrhage = loss of blood Thrombosis = when a blood clot forms inside a blood vessel which has NOT been damaged (natural anti-coagulants aren’t efficient) Embolus = blood clot, air bubble, fat globule, or debris that gets released into the bloodstream Stroke = blood vessels in brain blocked, due to clot or hemorrhage; leads to cerebral ischemia Hemophilia = several different factor deficiencies; “free-bleeder” Normal coagulation requires vitamin K Coumadin = common anticoagulant Feb 14th: Respiratory system AND Feb 19th: Diseases of the respiratory system Anatomy of the Respiratory system = nose, pharynx, larynx, trachea, bronchi, lungs Upper Resp. Tract: External part of nose - bone, hyaline cartilage & skin; lined with m-mb External nares = nostrils (single: naris) Internal part of nose Nasal cavity = space inside the internal nose; lined with ciliated m-mb (cilia move mucus DOWNward) Nasal septum = vertical dividing wall; bones at back/hyaline at front Front portion of nasal cavity = vestibules At back of nasal cavity = internal nares (choanae); open into pharynx Paranasal sinuses (lined with m-mb) → drain into nasal cavity (also resonate for speech sounds) Nose is adapted for warming, moistening, & filtering air (nasal conchae) Also receives olfactory stimuli (m-mb of superior conchae & nasal septum) & involved in speech Pharynx = throat = muscular tube lined with m-mb Nasopharynx = upper (superior) part of pharynx; behind nasal cavity (lined with ciliated m-mb) Internal nares open into nasopharynx; carry warmed air & mucus Eustacian tubes open into nasopharynx; equalize air P in middle ear On posterior wall = pharyngeal tonsil (adenoid) Oropharynx = midsection of pharynx (throat culture site) Passageway for both air & food (NO cilia; m-mb) Palatine tonsils (sides) & lingual tonsils (base of tongue) Laryngopharynx = lower portion of pharynx continues down as the esophagus (NO cilia; m-mb) connects at the front with the larynx (voicebox) passageway for both air & food Lower Resp. Tract: Larynx = voice box sits btwn. the laryngopharynx & the trachea made up of 9 pieces of cartilage (blue), all held together by ligaments Thyroid cartilage = Adam’s apple hyaline cartilage plate (actually 2 fused plates) connected to hyoid bone by a ligament Epiglottis = leaf-shaped “flap” at top of thyroid cartilage elastic cartilage, covered with epithelium attached at front edge when you swallow, the larynx moves UP, “closing” the epiglottis (prevents food from entering the larynx) Cricoid cartilage = connects the larynx & trachea ring of cartilage just above top of trachea perform tracheostomy just below cricoid cartilage Larynx also contains 3 additional paired cartilages, which support the vocal folds Vocal folds = true vocal cords; produce sound by vibrating 2 pair of folds: false & true vocal folds Slit-like opening between vocal folds = glottis When elastic ligaments stretch the vocal folds tight → fast vibrations → high pitches When relaxed → slow vibrations → low pitches Laryngitis = inflammation of the vocal folds; can’t vibrate properly (hoarseness; loss of voice) Lower portion of larynx is lined with ciliated m-mb; cilia move mucus UP Trachea = windpipe Connects larynx to primary bronchi Trachea is made of smooth muscle & C-shaped rings of cartilage Lined with ciliated m-mb (moves mucus UPward to be swallowed) Bronchi Bronchial tree: trachea primary bronchi = sm.muscle & C-rings of cart; lined w/ ciliated m-mb 1o bronchi branch into secondary bronchi Right lung has 3 secondary (lobar) bronchi; 3 lobes Left lung has 2 secondary (lobar) bronchi; 2 lobes 2o bronchi branch into tertiary (segmental) bronchi (there are 10 3o bronchi in each lung) these divide into bronchioles, which branch even further Terminal bronchioles no longer ciliated; simple cuboidal epithelium cartilage C-rings have gradually disappeared amt. of circular smooth muscle has gradually increased Smooth muscle of bronchial tree is innervated by ANS During exercise & emergencies, S division of cause bronchodilation When PS division overrides → bronchoconstriction Allergic rxns. also cause constriction (asthma; anaphylaxis) Lungs Paired organs in the thoracic cavity Enclosed & protected by the pleural membrane (serous / double mb) Parietal pleura = outer layer; attached to wall of thoracic cavity Visceral pleura = inner layer; covers the lungs themselves Pleural cavity = tiny space between these 2 layers Pleura secrete a lubricating serous fluid (pleural fluid) into the pl-cavity Air in the pleural cavity (thoracic wound or surgery) = pneumothorax Blood in the pleural cavity (trauma, inf.) = hemothorax Pus may also accumulate in pleural cavity, with pulmonary inf. Pleurisy = inflammation of pleura (friction pain is major symptom) Pleural effusion = accumulation of fluid in pleural cavity (inf. or cancer) Right lung has 3 lobes, separated by 2 fissures Left lung has 2 lobes, separated by 1 fissure; also contains a depression called the cardiac notch (for the heart) Each terminal bronchiole branches into microscopic branches = respiratory bronchioles, which branch into several alveolar ducts Each alveolar duct bulges out to form several alveolar sacs of alveoli Each alveolus is made up mostly of simple squamous epithelium (terminal bronchiole was simple cuboidal epithelium) The lungs have a double blood supply Pulmonary circulation = pulm. arteries & pulm. veins Systemic circulation bronchial arteries branch off the aorta; bring O2 blood to lungs This blood does NOT pick up O2 from the alveoli; it nourishes the lung tissue Pulmonary Ventilation = breathing Inspiration = inhalation Expiration = exhalation Breathing Patterns Eupnea = normal breathing Dyspnea = labored breathing; difficulty breathing Tachypnea = rapid breathing Costal breathing = shallow breathing Diaphragmatic breathing = deep breathing Pulmonary Air Volumes & Capacities Measure with a spirometer Tidal Volume = volume of 1 normal breath (inspiration / expiration) ~500mL Anatomical dead space = 150 mL of TV never reaches alveoli Inspiratory Reserve = additional air which can be forcefully inspired (in addition to TV) ~3100 mL Expiratory Reserve = additional air which can be forcefully expired (in addition to TV) ~1220 mL Residual Volume = air which cannot be forced from the lungs remains at all times cannot be measured! ~1200 mL Control of Respiration Respiratory Center = scattered group of neurons in the medulla & pons 3 functional areas: Medullary rhythmicity area = controls the basic rhythm of respiration Pneumotaxic area = located in the pons sends impulses that limit inspiration / facilitate expiration prevents overexpansion of the lungs Apneustic area = located in the pons sends impulses to activate the inspiratory area (in the medulla) stimulates inspiration / inhibits expiration Respiration Rate can be modified by several factors: Cerebral cortex (voluntary change in RR; ex: hold breath in water) Chemical stimuli Buildup of CO2 / H+ (↓ pH) in the blood strongly stimulates the Inspiratory area of the medulla Hypoxia also increases RR Feb 25th: Digestive system anatomy Anatomy of the Digestive System: GI tract (alimentary canal) = continuous tube running thru the ventral body cavity, mouth to anus Accessory structures, Teeth, Tongue, Salivary glands, Liver, Gallbladder, Pancreas Digestive Process: Ingestion Movement = peristalsis Secretion (water, HCl, buffers, enzymes) Digestion = process of breaking down large food particles into molecules which are small enough to enter body cells Mechanical digestion = chewing, churning, mixing with secretions Chemical digestion = series of catabolic (hydrolysis) rxns. that break down large CHO, lipid, & protein food particles into smaller molecules that can be used by body cells Absorption = moving these nutrient molecules from GI tract into blood / lymph Defecation = emptying of the rectum, to remove indigestible substances Mouth = buccal cavity Uvula = muscular process which hangs from the back of the soft palate Tongue = forms the floor of the oral cavity Salivary glands Saliva = continuous secreted into the mouth; increased amount of saliva secreted with presence of food in mouth / nervous stimulation, Lubricates; keeps oral and pharyngeal m-mb’s moist, Helps to dissolve food, Starts chemical digestion of CHO’s (contains the enzyme amylase) 3 pairs of major salivary glands: parotid, submandibular, sublingual Teeth = dentes Adapted for mechanical digestion (chewing) 3 main portions: Crown = above the gums, Root = below the gums; coated with cementum (bonelike substance), Neck = at the gum line Composed mostly of dentin = calcified CT covered by enamel (harder than bone) above the gums covered by cementum below the gums Tooth socket contains a periodontal ligament = fibrous CT lining 2 dentitions (sets of teeth) in each person’s life Deciduous = primary teeth = baby teeth (20) Permanent = secondary teeth (32, including wisdom teeth) 4 different types of teeth (based on shape) Incisors = used to cut food; 2 pair (upper & lower) Cuspids = canines = used to tear or shred food; 1 pair (upper & lower) Premolars = bicuspids Molars = used for crushing / grinding food also Esophagus = muscular tube behind the trachea; connects pharynx to stomach Moves the bolus by peristalsis; NO chemical digestion Esophagus contains upper and lower esophageal sphincters Stomach Shaped like a “J” = stomach is just a wide place in the GI tract 4 main regions: Cardia = Right uppermost; just past the lower esophageal sphincter Fundus = Left uppermost Body = middle, curved portion of stomach Pylorus = lower portion; attaches to the duodenum Lining of stomach contains folds (rugae), similar to bladder lining Gastric glands; located in gastric pits: HCl, mucus (protective),other enzymes Only a few substances are absorbed thru the stomach wall: some water electrolytes certain drugs (aspirin) alcohol Pancreas posterior to lower stomach Pancreas is connected to duodenum by 2 ducts (pancreatic & accessory) Tiny patches of cells (1%) = Secrete hormones, 99% of pancreas cells = Secrete pancreatic juice: Pancreatic amylase → breaks down CHO’s Trypsin, chymotrypsin, carboxypeptidase → digest proteins Pancreatic lipase → digests fats Ribonuclease & deoxyribonuclease → digest nucleic acids Liver = 2nd largest organ of the body Large right lobe + small left lobe (positioned behind lower sternum), Produce bile → thru a duct system to gallbladder for storage, Gallbladder then secretes bile when stim’d by nervous / hormones Functions of the Liver CHO metabolism Lipid metabolism Protein metabolism Also convert one AA to another AA, as needed by the body Liver removes & detoxifies certain drugs & hormones from the blood Liver stores vitamins (A, B12, D, E, K) and minerals (ferritin, Cu, etc.) Gallbladder stores & concentrates the bile Small Intestines, Duodenum = top end; connected to pyloric sphincter, Jejunum, Ileum = lower end; connected to large intestine at ileocecal sphincter Small intestine is highly adapted for digestion & absorption, Large surface area for aborption Absorption = passage of end products of digestion from GI tract into blood or lymph (90% of absorption occurs in the small intestine) Large Intestine = Colon, Cecum = a blind pouch about 2.5” long; hangs below the ileocecal sphincter, Vermiform appendix = coiled tube attached to the cecum; 3” long, Colon (4 parts), Rectum = anterior to the sacrum & coccyx; about 8” long, Anus = outer opening of the large intestine Internal anal sphincter = smooth muscle (involuntary) External anal sphincter = skeletal muscle (voluntary) More water gets absorbed in the Colon (liquid chyme → solid/semisolid feces) Feb 26th: Disorders and procedures of the digestive system Parotitis – mumps, swollen parotid salivary glands, bacterial Heartburn – chyme pushed up esophagus due to incomplete closure of the esophageal sphincter Vomiting – noxious chemicals, disease, motion Gall stones – cholesterol crystals formed in gall bladder Colon cancer – rectal bleeding, anemia Appendicitis – inflammation, peritonitis, shock, caused by bacterial infection or fecolith Diarrhea – speed bowel up Constipation – slow bowel down Stomach ulcers – lack of mucous bacteria or Nsaids creates a hole Celiac disease – autoimmune, chronic diarrhea, fatigue, failure to thrive in children Cystic fibrosis – recessive genetic disease, chloride channel not transported across membrane, malabsorption in gut cannot exchange water, pancreas does not make enzymes well Appendectomy – cut off appendix Cholecystectomy – cut off gall bladder Endoscopy – sending fiber optic camera into esophagus to evaluate and band bleeding vessels Colonoscopy – sending fiber optic camera into colon to evaluate and take biopsy Short gut syndrome – genetic abnormality short small intestinal tract Comb procedure – zipper cut the intestines to increase length, fix short gut Whipple – surgical removal of pancreatic cancer, attach remaining pancreas to duodenum, attach stomach to jejunum, duodenum become duct for pancreatic and liver secretions Crazy surgical options: 100lbs overweight, bmi of 40 Lap band – plastic band around stomach that can be tightened, removable surgically Gastric bypass – any rearranging or skipping of the stomach or small intestines Roux-en-y – cut off most of stomach, attaches small egg sized portion to the jejunum, caused malabsorption Feb 28th: Diet types gluten free, vegetarian, vegan, diabetes, Atkins, south beach, lactose intolerant Healthy diet = A healthy diet is one that helps maintain or improve general health. It is important for lowering many chronic health risks, such as obesity, heart disease, diabetes, hypertension and cancer. A healthy diet involves consuming appropriate amounts of all essential nutrients and an adequate amount of water. Nutrients can be obtained from many different foods, so there are numerous diets that may be considered healthy. A healthy diet needs to have a balance of macronutrients (fats, proteins, and carbohydrates), calories to support energy needs, and micronutrients to meet the needs for human nutrition without inducing toxicity or excessive weight gain from consuming excessive amounts. Gluten free = A gluten- -free diet is a diet that excludes foods containing gluten. Gluten is a protein found in wheat (including kamut and spelt), barley, rye, malts and triticale. It is used as a food additive in the form of a flavoring, stabilizing or thickening agent, often as "dextrin". A gluten-free diet is the only medically accepted treatment for celiac disease, the related condition dermatitis herpetiformis, and wheat allergy. Additionally, a gluten-free diet may exclude oats. Medical practitioners are divided on whether oats are an allergen to celiac disease(chronic diarrhea and failure to thrive) sufferers or if they are crosscontaminated in milling facilities by other allergens. The term gluten-free is generally used to indicate a supposed harmless level of gluten rather than a complete absence. The exact level at which gluten is harmless is uncertain and controversial. A recent systematic review tentatively concluded that consumption of less than 10 mg of gluten per day is unlikely to cause histological abnormalities, although it noted that few reliable studies had been done. Regulation of the label gluten-free varies widely by country. In the United States, the FDA issued regulations in 2007 limiting the use of "gluten-free" in food products to those with less than 20 ppm of gluten. Vegetarian and Vegan= Vegetarianism encompasses the practice of following plant-based diets (fruits, vegetables, etc.), with or without the inclusion of dairy products or eggs, and with the exclusion of meat (red meat, poultry, and seafood). Abstention from by-products of animal slaughter, such as animal-derived rennet and gelatin, may also be practiced.[2][3] Vegetarianism can be adopted for different reasons: In addition to ethical reasons, motivations for vegetarianism include health, religious, political, environmental, cultural, aesthetic or economic. There are varieties of the diet as well: an ovo-vegetarian diet includes eggs but not dairy products, a lacto- vegetarian diet includes dairy products but not eggs, and an ovo-lacto vegetarian diet includes both eggs and dairy products. A vegan diet excludes all animal products, including eggs, dairy, and honey. Diabetic diet = The basics to diabetic diet meal planning are simple once we understand the way our body breaks down food. Everything we eat is broken down into sugar eventually. Sugary foods such as sweets or fruit hit the bloodstream almost immediately, followed by the slower starches (carbohydrates, or carbs), which take an hour or two to break down depending on their complexity. Proteins are next, taking about four hours, then between six and eight hours the fats finally break down. If strict attention is paid to diet and exercise, many diabetics can control their blood sugar with minimal dependence on medication. Atkin’s diet = The Atkins diet involves limited consumption of carbohydrates to switch the body's metabolism from metabolizing glucose as energy over to converting stored body fat to energy. This process, called ketosis, begins when insulin levels are low; in normal humans, insulin is lowest when blood glucose levels are low (mostly before eating). Ketosis lipolysis occurs when some of the lipid stored in fat cells are transferred to the blood and are thereby used for energy. On the other hand, caloric carbohydrates (for example, glucose or starch, the latter made of chains of glucose) impact the body by increasing blood sugar after consumption. (In the treatment of diabetes, blood sugar levels are used to determine a patient's daily insulin requirements.) Fiber, because of its low digestibility, provides little or no food energy and does not significantly impact glucose and insulin levels. In his book Dr Atkins' New Diet Revolution, Atkins made the controversial argument that the lowcarbohydrate diet produces a metabolic advantage because "burning fat takes more calories so you expend more calories." He cited one study where he estimated this advantage to be 950 calories (4.0 MJ) per day. A review study published in the Lancet concluded that there was no such metabolic advantage and dieters were simply eating fewer calories because of boredom. Professor Astrup stated, "The monotony and simplicity of the diet could inhibit appetite and food intake". The Atkins Diet restricts "net carbs" (digestible carbohydrates that impact blood sugar). One effect is a tendency to decrease the onset of hunger, perhaps because of longer duration of digestion (fats and proteins take longer to digest than carbohydrates). Atkins states in his 2002 book New Diet Revolution that hunger is the number one reason why low-fat diets fail and that the Atkins diet is easier because you are allowed to eat as much as you want South beach diet = According to Agatston, hunger cycles are triggered not by carbohydrates in general, but by carbohydrate-rich foods that the body digests quickly, creating a spike in blood sugar. Such foods include the heavily refined sugars and grains that make up a large part of the typical Western diet. The South Beach Diet eliminates these carbohydrate sources in favor of relatively unprocessed foods such as vegetables, beans, and whole grains. Carbohydrate sources are considered "good" only if they have a low glycemic index. Given that South Beach Diet was designed by a cardiologist, it should be no surprise that it eliminates trans-fats and discourages saturated fats. Although foods rich in these "bad fats" do not contribute to the hunger cycle, they do contribute to LDL cholesterol and heart disease. The South Beach Diet replaces them with foods rich in unsaturated fats and omega-3 fatty acid which contribute to HDL cholesterol and provide other health benefits. Specifically, the diet excludes the fatty portions of red meat and poultry, replacing them with lean meats, nuts, and oily fish. Agatston divides the South Beach Diet into three phases, each progressively becoming more liberal. "Phase 1" lasts for the first two weeks of the diet. It eliminates all sugars, processed carbohydrates, fruits, and some higher-glycemic vegetables as well. Its purpose is to eliminate the hunger cycle and is expected to result in significant weight loss. "Phase 2" continues as long as the dieter wishes to lose weight. It re-introduces most fruits and vegetables and some whole grains as well. "Phase 3" is the maintenance phase and lasts for life. There is no specific list of permitted and prohibited foods. Instead, the dieter is expected to understand the basic principles of the diet and live by the principles Lactose intolerant = Lactose intolerance, also called lactase deficiency or hypolactasia, is the inability to digest and metabolize lactose, a sugar found in milk. It is caused by a lack of lactase, the enzyme required to break down lactose in the digestive system, and results in symptoms including abdominal pain, bloating, flatulence, diarrhea, nausea and acid reflux. Most mammals normally become lactose intolerant when they are young but some human populations have developed lactase persistence, in which lactase production continues into adulthood. It is estimated that 75% of adults worldwide show some decrease in lactase activity during adulthood. The frequency of decreased lactase activity ranges from 5% in northern Europe through 71% for Sicily to more than 90% in some African and Asian countries. Lactose is a water-soluble molecule. Therefore fat percentage and the curdling process affect tolerance of foods. After the curdling process lactose is found in the water portion (along with whey and casein) but not in the fat portion. Dairy products that are "fat reduced" or "fat free" generally have a slightly higher lactose percentage. Low fat dairy foods, additionally, often have various dairy derivatives such as milk solids added to them to enhance sweetness, increasing the lactose content March 5th: Obesity eating disorders National Institute of Mental Health Eating disorders - An eating disorder is an illness that causes serious disturbances to your everyday diet, such as eating extremely small amounts of food or severely overeating. A person with an eating disorder may have started out just eating smaller or larger amounts of food, but at some point, the urge to eat less or more spiraled out of control. Severe distress or concern about body weight or shape may also characterize an eating disorder. Eating disorders frequently appear during the teen years or young adulthood but may also develop during childhood or later in life. Common eating disorders include anorexia nervosa, bulimia nervosa, and binge-eating disorder. Eating disorders are real, treatable medical illnesses. They frequently coexist with other illnesses such as depression, substance abuse, or anxiety disorders. Anorexia – Extreme thinness (emaciation) A relentless pursuit of thinness and unwillingness to maintain a normal or healthy weight Intense fear of gaining weight Distorted body image, a self-esteem that is heavily influenced by perceptions of body weight and shape, or a denial of the seriousness of low body weight Lack of menstruation among girls and women Extremely restricted eating. Many people with anorexia nervosa see themselves as overweight, even when they are clearly underweight. Eating, food, and weight control become obsessions. People with anorexia nervosa typically weigh themselves repeatedly, portion food carefully, and eat very small quantities of only certain foods. Some people with anorexia nervosa may also engage in binge-eating followed by extreme dieting, excessive exercise, self-induced vomiting, and/or misuse of laxatives, diuretics, or enemas. Some who have anorexia nervosa recover with treatment after only one episode. Others get well but have relapses. Still others have a more chronic, or long-lasting, form of anorexia nervosa, in which their health declines as they battle the illness. Other symptoms may develop over time, including:6,7 Thinning of the bones (osteopenia or osteoporosis) Brittle hair and nails Dry and yellowish skin Growth of fine hair all over the body (lanugo) Mild anemia and muscle wasting and weakness Severe constipation Low blood pressure, slowed breathing and pulse Damage to the structure and function of the heart Brain damage Multiorgan failure Drop in internal body temperature, causing a person to feel cold all the time Lethargy, sluggishness, or feeling tired all the time Infertility. Bulimia - Bulimia nervosa is characterized by recurrent and frequent episodes of eating unusually large amounts of food and feeling a lack of control over these episodes. This binge-eating is followed by behavior that compensates for the overeating such as forced vomiting, excessive use of laxatives or diuretics, fasting, excessive exercise, or a combination of these behaviors. Unlike anorexia nervosa, people with bulimia nervosa usually maintain what is considered a healthy or normal weight, while some are slightly overweight. But like people with anorexia nervosa, they often fear gaining weight, want desperately to lose weight, and are intensely unhappy with their body size and shape. Usually, bulimic behavior is done secretly because it is often accompanied by feelings of disgust or shame. The binge-eating and purging cycle happens anywhere from several times a week to many times a day. Other symptoms include: Chronically inflamed and sore throat Swollen salivary glands in the neck and jaw area Worn tooth enamel, increasingly sensitive and decaying teeth as a result of exposure to stomach acid Acid reflux disorder and other gastrointestinal problems Intestinal distress and irritation from laxative abuse Severe dehydration from purging of fluids Electrolyte imbalance (too low or too high levels of sodium, calcium, potassium and other minerals) which can lead to heart attack. Binge eating - With binge-eating disorder a person loses control over his or her eating. Unlike bulimia nervosa, periods of binge-eating are not followed by purging, excessive exercise, or fasting. As a result, people with binge-eating disorder often are over-weight or obese. People with binge-eating disorder who are obese are at higher risk for developing cardiovascular disease and high blood pressure. They also experience guilt, shame, and distress about their binge-eating, which can lead to more binge-eating. Treatment - Adequate nutrition, reducing excessive exercise, and stop-ping purging behaviors are the foundations of treatment. Specific forms of psychotherapy, or talk therapy, and medica-tion are effective for many eating disorders. However, in more chronic cases, specific treatments have not yet been identified. Treatment plans often are tailored to individual needs and may include one or more of the following: Individual, group, and/or family psychotherapy Medical care and monitoring Nutritional counseling Medications. Some patients may also need to be hospitalized to treat problems caused by mal-nutrition or to ensure they eat enough if they are very underweight. Males - Like females who have eating disorders, males also have a distorted sense of body image. For some, their symptoms are similar to those seen in females. Others may have muscle dysmorphia, a type of disorder that is characterized by an extreme concern with becoming more muscular. Unlike girls with eating disorders, who mostly want to lose weight, some boys with muscle dysmorphia see themselves as smaller than they really are and want to gain weight or bulk up. Men and boys are more likely to use steroids or other dangerous drugs to increase muscle mass. Although males with eating disorders exhibit the same signs and symptoms as females, they are less likely to be diagnosed with what is often considered a female disorder. More research is needed to understand the unique features of these disorders among males. Metabolism – life period, exercise quantity, genetic factors Obesity – evolutionarily designed to hold on to calories and crave salty, sweet, greasy Thyroidism – hypothyroidism weight gain Recommended daily caloric intake equation: MALE: 105 lbs for first 5’, 6 lbs for every additional inch of height, +/- 15 lbs for build = Ideal Weight FEMALE: 100 lbs for first 5’, 5 lbs for every additional inch of height, +/- 15 lbs for build = Ideal Weight Caloric Use: average Ideal and Actual weights x 10 x 1.5 (sedentary) or 1.7 (exercise 3 days per week) or 2.0 (exercise every day) = Number of Calories you burn each day 1 lb of fat = 3,500 Cal; if you ingest 500 less Cal per day you will lose 1 lb of fat per week Mar 7th: Substance abuse Substance abuse, also known as drug abuse, refers to a maladaptive pattern of use of a substance (drug) that is not considered dependent. Substance abuse/drug abuse does is not limited to moodaltering or psycho-active drugs. Activity is also considered substance abuse when inappropriately used (as in the case of propofol and Michael Jackson's death, or steroids for performance enhancement in sports). Therefore, mood-altering and psychoactive substances are not the only drugs of abuse. Substance abuse often includes problems with impulse control and impulsivity. The term "drug abuse" does not exclude dependency, but is otherwise used in a similar manner in nonmedical contexts. The terms have a huge range of definitions related to taking a psychoactive drug or performance enhancing drug for a non-therapeutic or non-medical effect. All of these definitions imply a negative judgment of the drug use in question (compare with the term responsible drug use for alternative views). Some of the drugs most often associated with this term include alcohol, amphetamines, barbiturates, benzodiazepines (particularly temazepam, nimetazepam, and flunitrazepam), cocaine, methaqualone, and opioids. Use of these drugs may lead to criminal penalty in addition to possible physical, social, and psychological harm, both strongly depending on local jurisdiction. Other definitions of drug abuse fall into four main categories: public health definitions, mass communication and vernacular usage, medical definitions, and political and criminal justice definitions. Substance abuse is a form of substance-related disorder. Alcohol – withdrawal can kill Public health issues April 1st: infection, spread, vectors, transmission, organisms, Typhoid Mary Infection = colonization of a host organism by parasite species Infecting parasites seek to use the host's resources to reproduce, often resulting in disease. Colloquially, infections are usually considered to be caused by microorganisms or microparasites like viruses, prions, bacteria, and viroids, though larger organisms like macroparasites and fungi can also infect. Hosts normally fight infections themselves via their immune system. Mammalian hosts react to infections with an innate response, often involving inflammation, followed by an adaptive response. Pharmaceuticals can also help fight infections. The branch of medicine that focuses on infections and pathogens is infectious disease medicine. Infections are classified in multiple ways. causative agent the constellation of symptoms and medical signs that are produced An infection that produces symptoms = apparent infection An infection that is active but no symptoms = inapparent, silent, or subclinical An infection that is inactive or dormant is called a latent infection A short-term infection is an acute infection A long-term infection is a chronic infection The symptoms of an infection depend on the type of disease. Some signs of infection affect the whole body generally, such as fatigue, loss of appetite, weight loss, fevers, night sweats, chills, aches and pains. Others are specific to individual body parts, such as skin rashes, coughing, or a runny nose. Colonization Infection begins when an organism successfully colonizes by entering the body, growing and multiplying. Most humans are not easily infected. Those who are weak, sick, malnourished, have cancer or are diabetic have increased susceptibility to chronic or persistent infections. Individuals who have a suppressed immune system are particularly susceptible to opportunistic infections. Entrance to the host generally occurs through the mucosa in orifices like the oral cavity, nose, eyes, genitalia, anus, or open wounds. While a few organisms can grow at the initial site of entry, many migrate and cause systemic infection in different organs. Some pathogens grow within the host cells (intracellular) whereas others grow freely in bodily fluids. Wound colonization refers to nonreplicating microorganisms within the wound, while in infected wounds replicating organisms exist and tissue is injured. All multicellular organisms are colonized to some degree by extrinsic organisms, and the vast majority of these exist in either a mutualistic or commensal relationship with the host. The variables involved in the outcome of a host becoming inoculated by a pathogen and the outcome include: the route of entry of the pathogen and the access to host regions that it gains the intrinsic virulence of the particular organism the quantity or load of the initial inoculant the immune status of the host being colonized Transmission In order for infecting organisms to survive and repeat the cycle of infection in other hosts, they (or their progeny) must leave an existing reservoir and cause infection elsewhere. Transmission of infections can take place via many potential routes. Infectious organisms may be transmitted either by direct or indirect contact. Persistent viral infections Many individuals develop a variety of infections in their lifetime, but quickly overcome them. However, some individuals develop chronic or persistent infections. In the majority of cases, persistent infections are caused by viruses and not bacteria. The most common persistent infections in North America include: HIV, hepatitis, herpes simplex, and, common to all mammals, endogenous retroviruses. Hepatitis B and C are usually acquired from the use of dirty needles, blood transfusions, or sexual intercourse. HIV has similar modes of transmission. Once hepatitis has been acquired, it becomes a chronic disorder. While some individuals with hepatitis B may remain asymptomatic, many will show active symptoms and remain infectious. In the long term, both hepatitis B and C can cause liver failure or liver cancer. In some cases, the signs and symptoms of liver damage may not appear for 20 years after the infection was initially acquired. Viable treatment and prevention strategies will disrupt the infection cycle. For example, direct transmission can be diminished by adequate hygiene, maintaining a sanitary environment, and health education. When infection attacks the body, anti-infective drugs can suppress the infection. Four types of anti-infective or drugs exist: antibacterial (antibiotic), antiviral, antitubercular, and antifungal. Herrerasaurus skull. Evidence of infection in fossil remains is a subject of interest for paleopathologists, scientists who study occurrences of injuries and illness in extinct life forms. Signs of infection have been discovered in the bones of carnivorous dinosaurs. When present, however, these infections seem to tend to be confined to only small regions of the body. A skull attributed to the early carnivorous dinosaur Herrerasaurus ischigualastensis exhibits pit-like wounds surrounded by swollen and porous bone. The unusual texture of the bone around the wounds suggests they were afflicted by a short-lived, non-lethal infection. Scientists who studied the skull speculated that the bite marks were received in a fight with another Herrerasaurus. Other carnivorous dinosaurs with documented evidence of infection include Acrocanthosaurus, Allosaurus, Tyrannosaurus and a tyrannosaur from the Kirtland Formation. The infections from both tyrannosaurs were received by being bitten during a fight, like the Herrerasaurus specimen. transmission = the passing of a communicable disease from an infected host individual or group to a conspecific individual or group, regardless of whether the other individual was previously infected. Sometimes transmission can specifically mean infection of a previously uninfected host. The term usually refers to the transmission of microorganisms directly from one person to another by one or more of the following means: droplet contact – coughing or sneezing on another person direct physical contact – touching an infected person, including sexual contact indirect physical contact – usually by touching soil contamination or a contaminated surface airborne transmission – if the microorganism can remain in the air for long periods fecal-oral transmission – usually from contaminated food or water sources Transmission can also be indirect, via another organism, either a vector (e.g. a mosquito) or an intermediate host (e.g. tapeworm in pigs can be transmitted to humans who ingest improperly cooked pork). Indirect transmission could involve zoonoses or, more typically, larger pathogens like macroparasites with more complex life cycles. Disease can be directly transmitted in two ways: Horizontal disease transmission – from one individual to another in the same generation (peers in the same age group). Horizontal transmission can occur by either direct contact (licking, touching, biting), or indirect contact air – cough or sneeze Vertical disease transmission – passing a disease causing agent vertically from parent to offspring, such as perinatal transmission. Vertical Transmission This is from mother to child, often in utero or during childbirth (also referred to as perinatal infection). It occurs more rarely via breast milk. Infectious diseases that can be transmitted in this way include: HIV, Hepatitis B and Syphilis. A vector is an organism that does not cause disease itself but that transmits infection by conveying pathogens from one host to another. Organisms of infection: Viruses Viroids Prions Bacteria Protozoa Fungi Candiru Mary Mallon (September 23, 1869 – November 11, 1938), also known as Typhoid Mary, was the first person in the United States identified as an asymptomatic carrier of the pathogen associated with typhoid fever. She was presumed to have infected some 53 people, three of whom died, over the course of her career as a cook. She was forcibly isolated twice by public health authorities and died after nearly three decades altogether in isolation. Mary Mallon was born in 1869 in Cookstown, County Tyrone, Ireland (now Northern Ireland). She emigrated to the United States in 1884. From 1900 to 1907 she worked as a cook in the New York City area. In 1900, she had been working in a house in Mamaroneck, New York, for under two weeks when the residents developed typhoid fever. She moved to Manhattan in 1901, and members of the family for whom she worked developed fevers and diarrhea and the laundress died. She then went to work for a lawyer until seven of the eight household members developed typhoid; Mary spent months helping to care for the people she made sick, but her care further spread the disease through the household. In 1906, she took a position in Oyster Bay, Long Island. Within two weeks, ten of eleven family members were hospitalized with typhoid. She changed employment again, and similar occurrences happened in three more households. When typhoid researcher George Soper approached Mallon about her possible role spreading typhoid, she adamantly rejected his request for urine and stool samples. Soper left and later published the report in June, 1907, in the Journal of the American Medical Association. On his next contact with her, he brought a doctor with him, but was turned away again. Mallon's denials that she was a carrier were based in part on the diagnosis of a reputable chemist who had found her to not harbor the bacteria. Moreover, when Soper first told her she was a carrier, the concept of a healthy carrier of a pathogen was not commonly known. Further, class prejudice and prejudice towards the Irish were strong in the period, as was the belief that slum-dwelling immigrants were a major cause of epidemics. During a later encounter in the hospital, he told Mary that he would write a book about her and give her all the royalties; she angrily rejected his proposal and locked herself in the bathroom until he left. The New York City Health Department sent Dr. Sara Josephine Baker to talk to Mary, but "by that time she was convinced that the law was only persecuting her when she had done nothing wrong." A few days later, Baker arrived at Mary's workplace with several police officers who took her into custody. The New York City health inspector determined her to be a carrier. Under sections 1169 and 1170 of the Greater New York Charter, Mallon was held in isolation for three years at a clinic located on North Brother Island. Individuals can develop typhoid fever after ingesting food or water contaminated during handling by a human carrier. The human carrier is usually a healthy person who has survived a previous episode of typhoid fever yet who continues to shed the associated bacteria, Salmonella typhi, in feces and urine. It takes vigorous scrubbing and thorough disinfection with soap and hot water to remove the bacteria from the hands. Eventually, the New York State Commissioner of Health, Eugene H. Porter, M.D., decided that disease carriers would no longer be held in isolation. Mallon could be freed if she agreed to abandon working as a cook and to take reasonable steps to prevent transmitting typhoid to others. On February 19, 1910, Mallon agreed that she "[was] prepared to change her occupation (that of a cook), and would give assurance by affidavit that she would upon her release take such hygienic precautions as would protect those with whom she came in contact, from infection". She was released from quarantine and returned to the mainland. After being given a job as a laundress, which paid lower wages, however, Mallon adopted the pseudonym Mary Brown, returned to her previous occupation as a cook, and in 1915 was believed to have infected 25 people, resulting in one death, while working as a cook at New York's Sloane Hospital for Women. Public-health authorities again found and arrested Mallon, returned to quarantine on the island on March 27, 1915. Mallon was confined there for the remainder of her life. She became something of a minor celebrity, and was interviewed by journalists, who were forbidden to accept even a glass of water from her. Later, she was allowed to work as a technician in the island's laboratory. Mallon spent the rest of her life in quarantine. Six years before her death, she was paralyzed by a stroke. On November 11, 1938, aged 69, she died of pneumonia. An autopsy found evidence of live typhoid bacteria in her gallbladder.[5] It is possible that she was born with the infection, as her mother had had typhoid fever during her pregnancy. Her body was cremated, and the ashes were buried at Saint Raymond's Cemetery in the Bronx. Mallon was the first healthy typhoid carrier to be identified by medical science, and there was no policy providing guidelines for handling the situation. Some difficulties surrounding her case stemmed from Mallon's vehement denial of her possible role, as she refused to acknowledge any connection between her working as a cook and the typhoid cases. Mallon maintained that she was perfectly healthy, had never had typhoid fever, and could not be the source. Public-health authorities determined that permanent quarantine was the only way to prevent Mallon from causing significant future typhoid outbreaks. Other healthy typhoid carriers identified in the first quarter of the 20th century include Tony Labella, an Italian immigrant, presumed to have caused over 100 cases (with five deaths); an Adirondack guide dubbed Typhoid John, presumed to have infected 36 people (with two deaths); and Alphonse Cotils, a restaurateur and bakery owner. Today, Typhoid Mary is a generic term for a healthy carrier of a noted pathogen, especially one who refuses to cooperate with health authorities to minimize the risk of infection. Mary Mallon is also referenced in popular culture in both the name of hip-hop group Hail Mary Mallon, and the name of Marvel comics character "Typhoid Mary". EXTRA: immunity, antibiotics, vaccines, disinfectants Non-Specific Immunity (Resistance to Disease) Pathogen = disease-causing org. Susceptible = lack of resistance Mechanical & Chemical barriers (First Line of Defense) skin provides a physical barrier against invaders, & sloughs dead cells Skin also has an acidic pH (3 to 5), which inhibits many pathogens Sweat contains lysozyme, which can break down bacterial cell walls mucus membranes trap invaders nasal hairs filter some pathogenic invaders, dust, pollens, etc. cilia in the bronchi "sweep" invaders upward to the throat, followed by a swallow, which sends the invaders to the stomach (coughing, sneezing also involved) tears (lacrimal apparatus) contain lysozyme Acidic pH (1.2 to 3) of the stomach kills many organisms Bile salts in the intestines can kill many organisms We can also remove invaders thru tears, saliva, urination, defacation, vomiting, etc. (dilute & wash away) Non-Specific Antimicrobial Substances (2nd Line of Defense) Interferons = proteins produced by virus-infected cells a. Interferons go to nearby host cells & bind to receptors on these cells b. This makes these cells less susceptible to virus infection; this inhibits viral replic. c. Interferons also enhance phagocytosis, supress tumor formation, etc. Complement System a. Group of plasma proteins which react in sequence to help destroy foreign invaders b. Certain of these C’ proteins are also involved in the inflam. response Natural Killer cells (lymphocytes) a. This type of lyphocyte is able to kill many different types of pathogens & tumor cells b. We don’t completely understand HOW they do this; currently being researched Phagocytosis = Ingestion & destruction of any foreign matter by cells Phagocytes = granulocytes (segs, EOs) and macrophages/monocytes Inflammatory Response 1. Inflammation = any time body cells are damaged by invaders, physical agents, chemicals 2. 4 cardinal symptoms = Redness, heat, swelling, pain 3. Histamine is released by many body cells when they are injured 4. Histamine causes vasodilation and increased permeability of blood vessels 5. Phagocytes frequently die after performing their duties a. these dead WBC’s + dead invaders forms a pocket of thick fluid (pus) b. If pus does not drain or cannot be absorbed by the body, is results in an abscess (prolonged inflammation → ulcers) 6. Together, the vasodilation & inc. perm. cause redness (erythema), heat, & swelling (edema) 7. Pain is due to increased pressure in the area, from irritation/damage to nerve fibers, and from kinins & prostaglandins (other chemicals involved in inflam. response) Fever 1. Fever creates a less favorable environment for many pathogens 2. Fever intensifies the effects of interferons 3. Fever also speeds up cellular repair Specific Immunity (Resistance to Disease) A. T and B Lymphocytes B. Antigen = any foreign molecule which enters the body and causes Ab-production Ag’s = usually large, complex structures which contain protein C. Cellular Immunity (Cell-mediated; cells attack cells) Responsible for tissue rejection, delayed hypersensitivity Types of T-lymphs: 1. T-cytotoxic cells(T8 cells)(T-Killer cells) 2. T-helper cells (T4 cells) a. 3. 4. [HIV destroys CD4 / T-helper cells] have surface protein CD4 T-suppressor cells a. inhibits proliferation of T and B cells b. Keeps our immune response under control T-memory cells The term antibiotic was coined by Selman Waksman in 1942 to describe any substance produced by a microorganism that is antagonistic to the growth of other microorganisms in high dilution. This definition excluded substances that kill bacteria, but are not produced by microorganisms (such as gastric juices and hydrogen peroxide). With advances in medicinal chemistry, most of today's antibacterials chemically are semisynthetic modifications of various natural compounds. Before the early 20th century, treatments for infections were based primarily on medicinal folklore. Mixtures with antimicrobial properties that were used in treatments of infections were described over 2000 years ago. Many ancient cultures, including the ancient Egyptians and ancient Greeks, used specially selected mold and plant materials and extracts to treat infections. More recent observations made in the laboratory of antibiosis between micro-organisms led to the discovery of natural antibacterials produced by microorganisms. Louis Pasteur observed, "if we could intervene in the antagonism observed between some bacteria, it would offer perhaps the greatest hopes for therapeutics". Antibiosis was first described in 1877 in bacteria when Louis Pasteur and Robert Koch observed that an airborne bacillus could inhibit the growth of Bacillus anthracis. These drugs were later renamed antibiotics by Selman Waksman, an American microbiologist, in 1942. After this initial chemotherapeutic compound proved effective, others pursued similar lines of inquiry but it was not until in 1928 that Alexander Fleming observed antibiosis against bacteria by a fungus of the genus Penicillium. Fleming postulated that the effect was mediated by an antibacterial compound named penicillin, and that its antibacterial properties could be exploited for chemotherapy. He initially characterized some of its biological properties, but he did not pursue its further development. A vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins. The agent stimulates the body's immune system to recognize the agent as foreign, destroy it, and "remember" it, so that the immune system can more easily recognize and destroy any of these microorganisms that it later encounters. The term vaccine derives from Edward Jenner's 1796 use of cow pox (Latin variola vaccinia, adapted from the Latin vaccīn-us, from vacca, cow), to inoculate humans, providing them protection against smallpox. The efficacy or performance of the vaccine is dependent on a number of factors: the disease itself (for some diseases vaccination performs better than for other diseases) the strain of vaccine (some vaccinations are for different strains of the disease) whether one kept to the timetable for the vaccinations (see Vaccination schedule) some individuals are "non-responders" to certain vaccines, meaning that they do not generate antibodies even after being vaccinated correctly other factors such as ethnicity, age, or genetic predisposition. When a vaccinated individual does develop the disease vaccinated against, the disease is likely to be milder than without vaccination. The following are important considerations in the effectiveness of a vaccination program: 1. 2. 3. careful modeling to anticipate the impact that an immunization campaign will have on the epidemiology of the disease in the medium to long term ongoing surveillance for the relevant disease following introduction of a new vaccine and maintaining high immunization rates, even when a disease has become rare. In 1958 there were 763,094 cases of measles and 552 deaths in the United States. With the help of new vaccines, the number of cases dropped to fewer than 150 per year. In early 2008, there were 64 suspected cases of measles. 54 out of 64 infections were associated with importation from another country, although only 13% were actually acquired outside of the United States; 63 of these 64 individuals either had never been vaccinated against measles, or were uncertain whether they had been vaccinated. Prior to vaccination, inoculation was practiced, and brought to the West in 1721 by Lady Mary Wortley Montagu, who showed it to Hans Sloane, the King's physician. Sometime during the 1770s Edward Jenner heard a milkmaid boast that she would never have the often-fatal or disfiguring disease smallpox, because she had already had cowpox, which has a very mild effect in humans. In 1796, Jenner took pus from the hand of a milkmaid with cowpox, inoculated an 8-year-old boy with it, and six weeks later variolated the boy's arm with smallpox, afterwards observing that the boy did not catch smallpox. Further experimentation demonstrated the efficacy of the procedure on an infant. Since vaccination with cowpox was much safer than smallpox inoculation, the latter, though still widely practiced in England, was banned in 1840. Louis Pasteur generalized Jenner's idea by developing what he called a rabies vaccine, and in the nineteenth century vaccines were considered a matter of national prestige, and compulsory vaccination laws were passed. The twentieth century saw the introduction of several successful vaccines, including those against diphtheria, measles, mumps, and rubella. Major achievements included the development of the polio vaccine in the 1950s and the eradication of smallpox during the 1960s and 1970s. Maurice Hilleman was the most prolific of the developers of the vaccines in the twentieth century. As vaccines became more common, many people began taking them for granted. However, vaccines remain elusive for many important diseases, including malaria and HIV. April 3rd: CDC, WHO, governmental agencies, current events, healthcare systems The Centers for Disease Control and Prevention (or CDC) is a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta. It works to protect public health and safety by providing information to enhance health decisions, and it promotes health through partnerships with state health departments and other organizations. The CDC focus national attention on developing and applying disease prevention and control (especially infectious diseases and foodborne pathogens and other microbial infections), environmental health, occupational safety and health, health promotion, injury prevention and education activities designed to improve the health of the people of the United States. The CDC is the United States' national public health institute and is a founding member of the International Association of National Public Health Institutes IANPHI. The CDC was founded in 1942 during World War II as the Office of National Defense Malaria Control Activities. The new agency was a branch of the U.S. Public Health Service and Atlanta was chosen as the location because malaria was endemic in the Southern United States. CDC leader Dr. Joseph Mountin continued to advocate for public health issues and to push for CDC to extend its responsibilities to many other communicable diseases. Currently the CDC focus has broadened to include chronic diseases, disabilities, injury control, workplace hazards, environmental health threats, and terrorism preparedness. CDC combats emerging diseases and other health risks, including birth defects, West Nile virus, obesity, avian, swine, and pandemic flu, E. coli, and bioterrorism, to name a few. The organization would also prove to be an important factor in preventing the abuse of penicillin. The CDC has one of the few Biosafety Level 4 laboratories in the country, as well as one of only two official repositories of smallpox in the world. The second smallpox store resides at the State Research Center of Virology and Biotechnology VECTOR in the Russian Federation. The World Health Organization (WHO) is a specialized agency of the United Nations (UN) that is concerned with international public health. It was established on 7 April 1948, with headquarters in Geneva, Switzerland and is a member of the United Nations Development Group. Its predecessor, the Health Organization, was an agency of the League of Nations. During the United Nations Conference on International Organization, references to health had been incorporated into the United Nations Charter at the request of Brazil. It similarly passed a declaration that an international health body would be set up, co-authored by Brazil and China. The Indian politician Jawaharlal Nehru also gave his opinion in favour of starting WHO. The constitution of WHO was developed from four documents, submitted by the French, British, United States and Yugoslav governments. There was a common consensus that membership should not be limited to members of the United Nations and to this effect other countries were allowed to send observers to the drafting process. The International Health Conference met between 19 June and 22 July 1946, attended by representatives of all 51 members of the UN, 13 non-member countries, 3 Allied Commission and 10 international organizations. Dr. Thomas Parran served as president of the conference. The two most discussed issues were the role of the Soviet Union (which accepted a place) and the integration of other international organizations, which was agreed and would be managed. The constitution of the World Health Organization had been signed by all 61 countries by 22 July 1946, which an article in Science described as "an historic day". It thus became the first specialised agency of the United Nations to which every member subscribed. Its constitution formally came into force on the first World Health Day on 7 April 1948, when it was ratified by the 26th member state. As of 2012, the WHO has 194 member states, including the Cook Islands and Niue. As of 2009, it also had two associate members, Puerto Rico and Tokelau. Non-members of the WHO include Liechtenstein and other states with limited diplomatic recognition. Several other entities have been granted observer status. Palestine is an observer as a "national liberation movement" recognised by the League of Arab States under United Nations Resolution 3118. The Holy See also attends as an observer, as does the Order of Malta. In 2010, the Republic of China was invited under the name of "Chinese Taipei". WHO Member States appoint delegations to the World Health Assembly, WHO's supreme decision-making body. All UN Member States are eligible for WHO membership, and, according to the WHO web site, "other countries may be admitted as members when their application has been approved by a simple majority vote of the World Health Assembly." In addition, the UN observer organizations International Committee of the Red Cross and International Federation of Red Cross and Red Crescent Societies have entered into "official relations" with WHO and are invited as observers. In the World Health Assembly they are seated along the other NGOs. April 25th: reproductive system types, internal external, sexual asexual, purpose Sexual vs. asexual Hermaphroditic Sequential vs. simultaneous Viviparous Oviparous Fertilization – internal vs. external Invertebrates Fish Amphibians Reptiles Birds Mammals Monotremes Marsupials Placental mammals Parthenogenesis April 29th: human female and male anatomy Organs of reproduction are grouped together: Gonads = produce gametes & secrete hormones (ovaries & testes) Ducts = transport, receive, & store gametes Accessory sex glands = produce materials that support the gametes Male Reproductive System Anatomy Gonads = testes System of ducts (ductus epididymis, ductus deferens, ejaculatory duct, urethra) Accessory sex glands (sem. vesicles, prostate gland, bulbourethra [Cowper’s] glands) Several supporting structures (penis, scrotum) Scrotum = cutaneous outpouching of the abdomen that supports the testes Inside, a vertical septum divides scrotum into 2 sacs Each sac contains 1 testis Prod. & survival of spermatozoa requires Temp. lower than core BT Temp. of the testes is regulated by the cremaster muscle elevates the testes closer to pelvic cavity to raise Temp. relaxes to move testes further from pelvic cavity to lower Temp. Testes Paired oval-shaped glands (gonads) in the scrotum Testes develop on the superior & posterior abdominal wall of the embryo During the 7th month of fetal development, the testes begin to move downward, thru the inguinal canals (“tunnels” in the anterior abdom. wall / extension of internal oblique muscle) Cryptorchidism = failure of one or both testes to descend Seminiferous tubules (sperm cells are made here) These tubules are lined with cells (various stages of developing sperm) Sertoli cells support & protect developing spermatogenic cells nourish spermatocytes, spermatids, & spermatozoa work with Testosterone & FSH during spermatogenesis release spermatozoa into the seminiferous tubules secrete fluid for sperm transport (rich in K+ and AA’s) secrete Inhibin (hormone) Leydig cells = interstitial cells produce testosterone (male sex hormone) Spermatogenesis = process by which the seminiferous tubules produce Involves BOTH meiosis & mitosis haploid spermatozoa Spermatogonium = most immature sperm cell (stem cell; diploid) Located just inside the basement mb of seminiferous tubule Stem cells = can undergo mitosis (replace themselves) Some spermatogonia mature into Primary spermatocytes (diploid) (move away from basement mb when this happens) o Each 1 spermatocyte then undergoes a reduction division (Meiosis I) o This forms 2 spermatocytes (haploid; sister chromatids still attached by centromere) o Each 2 spermatocyte then undergoes an equatorial div. (Meiosis II) Just like mitosis End with 4 NON-identical haploid spermatids (DNA NOT dupl’d) Spermatids located near the lumen of seminiferous tubule Spermiogenesis = last stage of spermatogenesis spermatids mature into spermatozoa Mature sperm: Head (with nucleus + acrosome, containing lysosome-like enz’s) Midpiece, containing many mitochondria for energy prod. Tail (flagellum) ~300 million sperm prod. / day; live ~48 hrs. inside female reprod. tract At puberty: GnRH (from hypothalamus) tells the Ant. Pit. to secrete FSH & LH FSH initiates spermatogenesis LH assists spermatogenesis & tells Leydig cells to secrete Testosterone Testosterone controls: Growth, development, fxn., and maintenance of sex organs (including sexual behavior, libido, etc.) Stim’s bone growth, protein anabolism (androgens are anabolic hormones; stim. protein synthesis) o Stim’s development of male 2 sex characteristics 1. wide shoulders 2. narrow hips 3. pubic, axillary, chest & facial hair 4. thickening of the skin 5. increased secretions from sebaceous glands 6. enlargement of the larynx (deepening of the voice) Stim’s sperm maturation Negative Feedback Loop regulates prod. of Testosterone When bld. Testosterone level rises, hypothal. secretes LESS GnRH This causes LESS LH to be secreted from Ant. Pit. Decreased LH leads to LESS Testosterone secreted by Leydig cells Sertoli cells are involved in regulation of spermatogenesis RATE a. Sertoli cells secrete the hormone Inhibin b. Inhibin tells the Ant. Pit. to secrete LESS FSH c. This causes spermatogenesis to slow down d. When more sperm are needed, Sertoli cells secrete LESS Inhibin Ducts in the Male Reproductive System Ducts of the testes a. Seminiferous tubules (curled & twisted) b. Straight tubules (in center of testis; after seminiferous) c. Rete testis (network of tubules in center of testis) Epididymis = comma-shaped organ behind each testis Each epididymis contains efferent ducts which receive the sperm from the Rete testis These efferent ducts then empty into the ductus epididymis Ductus epididymis = very tightly coiled tubule (+ smooth muscle) Made up of pseudostratified columnar epithelial cells, which contain stereocilia (microvilli; inc. surface area; NONmoving) Sperm mature (at least 1 month) in the epididymis; then they are either ejaculated or (resorbed) Ductus (vas) Deferens Also called the seminal duct (+ 3 layers of smooth muscle) Stores sperm, & propels them toward urethra during ejaculation Vasectomy = cutting of the vas deferens to prevent fertilization Ductus deferens loops: 1. UP behind the epididymis, 2. OVER the pubic symphysis, 3. penetrates the inguinal canal, enters the pelvic cavity, 4. OVER the ureter & lateral to the urinary bladder, 5. DOWN behind the bladder 6. Empties into ejaculatory duct / urethra Spermatic cord = supporting structure of male reprod. system 1. Ductus deferens 2. Blood vessels, nerves, & lymphatic vessels 3. Cremaster muscle (which raises / lowers the scrotum) 4. Spermatic cord passes thru the inguinal canal (inguinal hernia = rupture or separation of this area from the abdominal wall; small intestine may bulge into inguinal canal) Ejaculatory ducts 1. Behind the urinary bladder (+ smooth muscle) 2. Where the duct from the seminal vesicle joins the vas deferens 3. Fxn. is to eject sperm into the prostatic urethra Male urethra = passageway for both urine & semen 1. Prostatic urethra (most superior portion; passes thru prostate gland) (+ smooth muscle) 2. Membranous urethra (middle portion; passes btwn. pubic rami) 3. Spongy (penile) urethra (empties to the exterior) Accessory Sex Glands Seminal vesicles a. Secrete an alkaline, viscous fluid (~60% of semen volume) b. This fluid contains fructose; helps sperm viability & motility c. Alkalinity helps to neutralize the acidic pH of vagina d. Seminal fluid also contains clotting proteins, which coagulate the semen within 5 min. after ejaculation Prostate gland = small, donut-shaped gland below the bladder a. Surrounds the prostatic urethra b. Secretes a milky, slightly acidic fluid (~15-30% of semen volume) c. This fluid contains citric acid, ACP, & several proteolytic enzymes (fxn. unknown) d. (PSA is one) These enzymes liquify coagulated semen (~20 min. after ejaculation) Bulbourethral (Cowper’s) glands = pea-size glands a. Below the prostate; ducts open into spongy urethra b. Secrete alkaline pH, to neutralize acids in urethra, + mucus, to lubricate / protect sperm during ejaculation Semen = mixture of sperm + accessory gland secretions 1. Secretions provide fluid for transport of sperm, nutrients for sperm, & also neutralizes the acidity of the male urethra & female vagina 2. Semen also contains a natural Abic = seminalplasmin ; controls bacteria in male urethra & female vagina 3. Semen Analysis = includes sperm count, volume, pH, motility, mobility, liquefaction, sperm morphology, etc. Penis 1. Used to introduce sperm into the vagina (ejaculation = propulsion of semen from urethra to exterior; sympathetic reflex) 2. Root = proximal portion; bulb of penis + crura, which attach the penis to the pubic rami; Root is surrounded by skeletal muscle tissue (for ejaculation) 3. Body = contains blood sinuses, arteries, & veins a. Also contains the spongy urethra (underside; ventral) b. Sexual excitation causes dilation of penile arteries & expansion of blood sinuses (parasympathetic response) c. All this blood compresses the veins which drain the penis; blood gets “trapped” erection 4. Glans penis = at distal end a. Prepuce = foreskin = loosely fitting skin covering the glans penis b. Circumcision = surgical removal of part or all of prepuce Female Reproductive System Anatomy 1. Ovaries (gonads) 2. Uterine tubes = Fallopian tubes 3. Uterus 4. Vagina 5. Vulva 6. Mammary glands also considered part of femal reprod. system 1. Located in the upper pelvic cavity, on either side of uterus 2. Held in place by a series of ligaments 3. Size & shape of unshelled almonds Ovaries Uterine (Fallopian) Tubes = also called oviducts 1. 2. Extend laterally from uterus Fxn: to transport 2o Oocytes & fertilized ova from the ovaries to the uterus 3. Fertilization occurs in oviducts (normally) 4. Anatomy of Oviducts a. b. Infundibulum = open, funnel-shaped portion, close to ovary fimbriae = fingerlike projections which sweep the 2o Oocyte into tube c. Oviducts contain smooth muscle, to propel ovum toward uterus d. Some cells also ciliated e. Ampulla = lateral 2/3 of tube; widest & longest; where fert. occurs f. Isthmus = medial, narrow part of tube 5. Takes ~7 days after ovulation for zygote (blastocyst) to get to uterus 1. 2. Size & shape of inverted pear; superior to urinary bladder Fxns: a. transport of spermatozoa into Fallopian tubes b. menstruation c. implantation of fertilized ovum d. development of fetus during pregnancy e. Labor 3. Anatomy of the uterus: Uterus a. Fundus = superior, dome-shaped portion b. Body = central, tapering portion c. Cervix = inferior, narrow part which opens into the vagina (cervical canal = about 1 cm long) 4. 1. Internal os = opening of cervix into uterine cavity 2. External os = opening of cervix into vagina Uterus is held in place by several ligaments 5. Histology of uterus: a. Perimetrium = outer layer; part of the visceral peritoneum b. Myometrium = middle layer; 3 layers of smooth muscle c. Endometrium = inner layer; MANY blood vessels (highly vascular) 1. Stratum functionalis = lines uterine cavity; shed each month 2. Stratum basalis = deeper, permanent layer; replaces the stratum functionalis each month after menstruation Vagina 1. Fxns: a. passageway for spermatozoa b. passageway for menstrual flow c. receptacle of penis during sexual intercourse d. lower portion of the birth canal 2. Located btwn. urinary bladder & rectum; directed superiorly & posteriorly 3. Fornix = “vault” which surrounds the vagina/cervix junction 4. Muscularis = double layer of smooth muscle; VERY elastic 5. Vaginal orifice may be partially covered by a thin fold of m-mb = hymen Vulva = external female genitalia 1. Mons pubis = mound of adipose tissue; cushins the pubic symphysis 2. Labia majora = adipose tissue, sebaceous & sudoriferous glands a. 3. 4. homologous to the scrotum (same embryonic origin) Labia minora = medial to labia minora a. hairless b. LITTLE adipose tissue, sudoriferous glands c. Many sebaceous glands Clitoris = Small, cylindrical mass of erectile tissue & nerves a. homologous to penis b. Prepuce = foreskin; point where the labia minora join; covers clitoris c. Glans = exposed portion of clitoris d. Clitoris enlarges during sexual arousal 5. Vestibule = area btwn. labia minora 6. Vaginal orifice = just posterior to urethral orifice 7. External urethral orifice = btwn. vaginal orifice & clitoris 8. Glands a. b. Paraurethral (Skene’s) glands = either side of urethral orifice 1. homologous to prostate gland 2. secrete mucus Greater vestibular (Bartholin’s) glands = either side of vag. orifice 1. homologous to Cowper’s glands 2. secrete mucus for lubrication during sexual arousal / intercourse Perineum = diamond-shaped area btwn. thighs & buttocks 1. Both males & females 2. Contains external genitals & anus 3. Site of episiotomy Mammary Glands 1. Modified sudoriferous glands; produce milk 2. Anterior to pectoralis major & serratus anterior muscles (lower/lateral) 3. Alveoli = milk-secreting cells; clustered in small lobules inside breasts 4. Development of mammary glands depends on estrogens & progesterone 5. Milk secretion = mainly due to prolactin 6. Milk ejection = stimulated by oxytocin (from Post. Pit. in response to suckling) April 30th: ovulation, menstrual cycle, menopause Phases of Female Reproductive Cycle Menstrual phase = first 5 days of cycle Stratum functionalis is shed (blood, tissue fluid, mucus, epi’s) Ovarian cycle is also occurring: Primary follicles begin to develop 20-25 primary follicles begin to produce low levels of estrogen At end of menstrual phase, ~20 of these develop into 2o follicles (each contains a 2o oocyte + several layers of cells) Preovulatory Phase = days 6-13 of a typical 28-day cycle Time btwn. menstruation & ovulation Endometrial repair occurs 1o follicles finish developing into 2o follicles Only one (occ. more) develops into a Graafian (mature) follicle This follicle produces a bulge on surface of ovary Estrogens are being produced by ovaries Ant. Pit. is secreting FSH at low, steady level At end of this phase, LH surge occurs Ovulation = rupture of Graafian follicle to release 2o oocyte Usually on day 14 Estrogens from ovaries + feedback loop more GnRH & LH This causes LH surge Signs of ovulation: Increased basal BT Clear, stretchy cervical mucus changes in uterine cervix ovarian pain Corpus hemorrhagicum = Graafian follicle forms blood clot (eventually resorbed) Corpus luteum = enlarged follicle cells; looks yellow secretes Estrogens & Progesterone stimulated by LH Postovulatory phase = days 15-28 Time btwn. ovulation & onset of next menses Also called the secretory phase; endometrial glands secrete glycogen (also called uterine milk ; prepares for implantation) Endometrium also thickens Ovaries (corpus luteum) enter the luteal phase = secrete LOTS of estrogen & progesterone Progesterone prepares endometrium for implantation IF fert./implantation do NOT occur, the corpus luteum degenerates into the corpus albicans (“white body”). P4 & E2 levels go down, followed by another menstrual cycle. IF fert. / implantation DO occur, the corpus luteum is maintained until the placenta takes over its hormone-producing fxns. Corpus luteum is maintained by hCH from the new placenta Corpus luteum secretes estrogens & progesterone to support pregnancy & breast development for lactation Once the placenta begins to secrete E2 & P4, the corpus luteum becomes less important (degenerates by 3rd-4th month) Menopause = term used to describe the permanent end of female fertility Menopause typically occurs in women in midlife late 40s or early 50s result of a reduction in female hormonal production by the ovaries This transition is normally not sudden or abrupt tends to occur over a period of years natural consequence of aging some women have signs and effects that can significantly disrupt their daily activities and sense of well-being. “The word menopause literally means the "end of monthly cycles" from the Greek word pausis (cessation) and the root men- (month), because the word "menopause" was created to describe this change in human females, where the end of fertility is traditionally indicated by the permanent stopping of monthly menstruation or menses.“ menopause also exists in some other animals, many of which do not have monthly menstruation; in this case, the term means a natural end to fertility that occurs before the end of the natural lifespan. In the Western world, the most typical age range for menopause (last period from natural causes) is between the ages of 40 and 61 and the average age for last period is 51 years. The average age of natural menopause (in Australia) is 51.7 years, although this varies considerably from one individual to another. In some countries however, such as India and the Philippines, the median age of natural menopause is considerably earlier, at 44 years. Menopause in the animal kingdom appears perhaps to be somewhat uncommon, but the presence of this phenomenon in different species has not been thoroughly researched. Life histories show a varying degree of senescence; rapid senescing organisms (e.g. Pacific salmon and annual plants) do not have a post-reproductive life-stage. Gradual senescence is exhibited by all placental mammalian life histories. Menopause has been observed in several species of nonhuman primates, including rhesus monkeys, and chimpanzees. Menopause also has been reported in elephants, short-finned pilot whales and other cetaceans, as well as in a variety of other vertebrate species including the guppy, the platyfish, the budgerigar, the laboratory rat and mouse, and the opossum, as well as some whales. However, with the exception of the short-finned pilot whale, such examples tend to be from captive individuals, and thus they are not necessarily representative of what happens in natural populations in the wild. EXTRA: pregnancy, issues, disorders, ectopic, miscarriage, fertility Reproduction = process by which new individuals of a species are produced, & the genetic material is passed from generation to gen. Gametes = Germ cells = sex cells = ova & sperm Haploid; each gamete contains only 23 chromosomes (remember: somatic cells have 23 pairs; diploid) Produced by meiosis = 2 successive nuclear divisions Review Mitosis Meiosis Homologous chrom’s = contain similar genes, in ess. same order Sex chrom’s = one pair of hom. chrom’s - designated X & Y Autosomes = other 22 pairs of homologous chrom’s Meiosis I = reduction division Interphase = chrom’s replicate (just like before mitosis) (now have 46 sets of sister chromatids) (2n x 2) Prophase I chrom’s get shorter / thicker nuclear envelope & nucleoli disappear mitotic spindle appears; centrioles migrate to poles chromatids arrange themselves into homologous pairs Synapsis = when the 2 (duplicated) homol. chrom’s form a tetrad now have 23 pairs of sets of sister chromatids (double X’s) Crossing over may occur = exchange of genetic info. btwn. tetrads (allows genetic recombination = new combo’s of genes; variation!) Metaphase I Homologous pairs (tetrads) line up at metaphase plate (remember, in mitosis, we only see single X’s at metaphase plate) Centromeres have protein complex (kinetochore) attached; this is for the spindle fibers (microtubules) to attach to Anaphase I Tetrads get pulled apart, into 2 sets of sister chromatids Centromeres still hold these sister chromatids together (in mitosis, the sister chromatids got pulled apart during Anaphase) Telophase I & Cytokinesis Just like mitosis: mitotic spindle falls apart Nuclear mb’s form around each daughter cell nucleus Overall, meiosis I (Reduction Div. = reduces # of chrom’s) results in 2 daughter cells which are haploid (23 chrom’s; still duplicated) (1n x 2) Interphase btwn. meiosis I and meiosis II = VERY brief Meiosis II = equatorial division 1. Prophase II 2. Metaphase II 3. Anaphase II 4. Telophase II Just like mitosis (end up with 1n x 1) Summary: Meiosis I start with 1 diploid cell (2n x 2) reduce # of chrom’s in each cell end up with 2 NONidentical haploid daughter cells (1n x 2) Meiosis II each haploid daughter cell divides separates the duplicate chrom’s into separate cells (1n x 1) end up with 4 NONidentical haploid daughter cells (gametes) Oogenesis During fetal development, oogonia = diploid stem cells of ovaries Oogonia reduction division (Meiosis I) begins, but arrests in Prophase I 1o Oocytes These 1o Oocytes remain “stuck” in Prophase I until puberty Puberty, each month 20-25 1o Oocytes finish Meiosis I 2o Oocytes + polar bodies with sister chromatids still attached by centromere) Polar body = haploid, just like 2o oocyte, but with very little cytoplasm About 20 2o Oocytes begin Meiosis II, but stop in Metaphase II At ovulation, only one 2o Oocyte is released from a mature (Graafian) follicle IF this 2o Oocyte does NOT become fertilized by a sperm, it degenerates IF this 2o Oocyte becomes fertilized by a sperm, Meiosis II continues: (haploid, 2o Oocyte splits into Ovum + 2nd polar body Nuclei of sperm & ovum unite diploid zygote Both polar bodies degenerate Ovarian Cycle = maturation of an ovum Uterine (Menstrual) Cycle = changes in endometrium to prepare for reception of a fertilized ovum Hormonal Regulation GnRH (from hypothalamus) stim’s release of FSH & LH from Ant. Pit. FSH stim’s initial development of ovarian follicles tells ovaries to secrete estrogens LH stim’s further development of ovarian follicles stim’s ovulation tells ovaries to secrete estrogens & progesterone Estrogens (beta-estradiol, estrone, estriol) promote the development & maintenance of female reprod. structures development & maint. of breasts development & maint. of 2o sex characteristics adipose tissue in breasts, abdomen, mons pubis, & hips broad pelvis voice pitch pattern of hair growth on head & body help regulate fluid & electrolyte balance stimulate protein synthesis Progesterone works with estrogens to prepare the endometrium for implantation works with estrogens to prepare mammary glands for milk synthesis Inhibin = inhibits secretion of FSH & GnRH Relaxin = relaxes pubic symphysis; helps dilate cervix for delivery EXTRA: mating strategies, mate selection Intersexual vs. intrasexual Beauty Human mate selection Sexual dimorphism Displays Aggression Monogamy vs. polygamy vs. promiscuity