Exercise Notes - Human Biology Notes PDF

Exercise 21: Arteries: carry blood away from the heart more elastic no valves thicker walls more smooth MT oxygen rich ◦pulmonary arteries (decrease O2) smaller lumen increase BP Veins: carry blood back to the heart less elastic valves thinner walls - oxygen poor...

Exercise 21: Arteries: carry blood away from the heart more elastic no valves thicker walls more smooth MT oxygen rich ◦pulmonary arteries (decrease O2) smaller lumen increase BP Veins: carry blood back to the heart less elastic valves thinner walls - oxygen poor ◦pulmonary veins (increase O2) larger lumen decrease BP Capillaries: gas exchanges made between tissues & blood through capillary walls one cell layer thick (tunica intima) thinness causes exchanges form networks called capillary beds 3 layers in blood vessels: tunica intima ◦forms a friction-reducing lining ◦endothelium tunica media ◦smooth muscle and elastic tissue ◦controlled by sympathetic nervous system tunica externa ◦forms protective outermost covering ◦mostly brous CT ◦supports & protects aorta: largest artery leaves from LV of heart superior vena cava: drains head and arms enter RA of heart inferior vena cava: drains lower body enter RA of heart sympathetic nervous system: promotes vasoconstriction (narrowing of blood vessels, increase BP) Exercise 22: systole: contraction diastole: relaxation cardiac cycle: includes events of one complete heartbeat both atria and ventricles contract and then relax changes in BV & BP occur in heart pulse: alternating surges of pressure (expansion & recoil) in an artery that occur with each beat of LV 70-76 BPM in resting state blood pressure: pressure that the blood exerts against the inner blood vessel walls measured in the arteries systolic pressure: the pressure in the arteries at the peak of ventricular contraction diastolic pressure: the pressure in the arteries at the peak of ventricular relaxation sphygomomanometer: blood pressure cu that measures BP cu is initiated to stop blood ow to the fore arm sounds of Korotko : sound of the blood spurting through the partially blocked artery indicate the resumption of blood ow into the fore arm cardiac output: amount of blood pumped out of the left ventricle per minute peripheral resistance: the amount of friction blood encounters as it ows through vessels increased PR = blood vessel constriction, increased blood viscosity/volume, loss of elasticity oxygenated blood traveling in the thoracic aorta passes the diaphragm into the abdominal aorta deoxygenated blood traveling from the liver back to heart enters through the inferior vena cava lub: AV valves close at the beginning of systole dup: semilunar valves close at the end of systole decrease in BP = increased diameter of aterioles, hemorrhage inrcrease in BP = increased blood viscosity, increased CO, arteriosclerosis, increased pulse rate Exercise 23 & 24 - The Respiratory System pulmonary ventilation: moving air into and out of the lungs (breathing) external respiration: gas exchange made between pulmonary blood and alveoli O2 is loaded into the blood CO2 is exerted internal respiration: gas exchange made between blood and tissue cells in systemic capillaries respiratory membrane: "air-blood barrier" one side of the membrane is air other side is blood owing past formed by alveolar and capillary walls respiratory zone structures: only site of gas exhange includes: respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli (air sacs) conducting zone structures: include all other pasageways tidal volume (TV): normal & quiet breathing 500 mL of air is moved in/out of lumgs with each breath residual volume: air remaining in lungs after exhalation cannot be voluntarily exhaled allows gas exchange to go on continuously helps keep alveoli open (in ated) 1,200 mL vital capacity: the total amount of exchangeable air TV+IRV+ERV 4,800 mL in men, 3,100 mL in women pharynx: throat, muscular passageway from nasal cavity to larynx nasopharynx: ◦most superior region of pharynx oropharynx: ◦region that houses the palatine & lingual tonsils  ◦common passageway for air & food laryngopharynx: ◦inferior region attatched to larynx ◦common passageway for air & food epiglottis: structure that prevents food from entering the trachea during swallowing gas exchange occurs across the respiratory membrane gas exchanges between blood & external environment occur only in alveoli of the lungs upper respiratory tract: passageways from nose to pharynx lower respiratory tract: passageways from trachea to alveoli passageways to the lungs purify, humidify, and warm incoming air respiratory mucosa: lines nasal cavity, traps foreign particles larynx: voice box, vocal folds routes air & food inferior to pharynx trachea: windpipe 4 in. tube connected to larynx lined with ciliated mucosa main bronchi: formed by division of trachea each bronchi enters lung at hilum lungs: occupy entire thoracic cavity except for central mediastinum each lung is divided into lobes by ssures ◦left lung = 2 lobes ◦right lung = 3 lobes serosa: covers outer surface of lungs visceral pleura: covers the lung surface parietal pleura: lines walls of thoracic cavity pleural uid: lls area between layers allows lungs to glide over thorax decreases friction during breathing pleural space (between layers) is more of a potential space alveoli: simple squamos epithelial cells largely compose the walls alveolar pores connect neighboring air sacs pulmonary capillaries: cover external surfacesof alveoli gas crosses the respiratory membrane by di usion oxygen enters the blood, CO2 enters alveoli inhalation: intrapulmonary volume increases, gas pressure decreases exhalation: intrapulmonary volume decreases, gas pressure increases Exercise 25 - The Digestive System Digestive system functions: digestion ◦breakdown of fod into smaller molecules absorption ◦small molecules are reabsorbed elimination ◦getting ridd of undigested remains accessory organs of digestive system liver & gallbladder ◦produce/secrete bile, detoxi cation of blood, secretion/storage of glucose, albumin pancreas ◦(exocrine), secretes into GI system, makes enzymes (amylase, trypsin, lipase) salivary glands ◦production/secretion of salivary amylase tonsils: part of body's defense system salivary glands: lubrication, antimicrobial agents & amylase cadioesophageal sphincter: controls food passage into the stomach a thickening of the smooth muscle layer at the esophagus-stomach junction duodenum: extends from pyloric sphincter for about 10 inches and curves around the head of the pancreas jejunum: continuous with the duodenum, extends for about 8 feet ileum: the terminal portion of the small intestine, about 12 feet long, joins large intestine at the ileocecal valve brush border: enzymes bound to the microvilli of the coulmnar epithelial cells enzymes produced by the pancreas are ducted into the duodenum via the pancreatic duct villi: ngerlike projections of the mucosa that give it a velvety appearance and texture circular folds: deep fold of the mucosal and submucosal layers that force chyme to spiral through the intestine, mixing it and slowing it's progress to allow time for digestion & absorption pharynx: common passageway for food espohagus: parynx to stomach, peristalsis small intestine & large intestine: absorption stomach: stores food, digestion of protein, kill bacteria, make chyme rectum: nal segement of large intestine, absorbing some elctrolytes & breaking down undigestible food by bacteria Exercise 26 - The Urinary System: functions of the urinary system in maintaing homeostasis kidneys dispose of waste products in urine ◦nitrogenous wastes, toxins, drugs, excess ions kidneys regulatory functions include ◦production of renin to maintain BP, production of erythropoietin to stimulate RBC production, conversion of vitamin D to it's active form structures of urinary system: kidneys, ureters, urinary bladder, urethra brous capsule: encloses kidney 3 regions of kidney: renal cortex (outer region) renal medulla (deeper region) renal pelvis (medial region) nephrons: structural and functional units of the kidneys 2 main structures ◦renal corpuscle ◦renal tubule 2 capillary beds ◦glomerulus ‣ fed and drained by arterioles ‣ ltration ‣ high pressure forces uid into glomerular capsule ◦peritubular capillary bed ‣ arise from e erent ‣ adapted for absorption a erent arterioles: feeds glomerulus e erent arterioles: receives blood from glomerulus urine formation is the result of glomerular ltration, tubular reabsorption, and tubular secretion solutes normally found in urine Na, K, & bicarbonate ions urea, uric acid, creatine ammonia Not found in urine: bile WBC's hemoglobin RBC's blood proteins glucose