BIOS 255 Anatomy & Physiology III with Lab – Final Exam (Each Question with Rationale)

This document is a comprehensive final exam for BIOS 255 (Anatomy & Physiology III) covering the cardiovascular, respiratory, renal, digestive, reproductive, immune/lymphatic systems, and lab/mixed review. It includes 150 multiple-choice questions with correct answers and detailed rationales. Topics include: left-sided heart failure (pulmonary edema), ventricular systole (ventricular pressure exceeds arterial pressure during ejection), left anterior descending (LAD) artery supplies left ventricle anterior wall, QRS complex (ventricular depolarization), blood flow sequence through the heart (RA → tricuspid → RV → pulmonary valve → pulmonary trunk → lungs → pulmonary veins → LA → mitral → LV → aortic valve → aorta), increased afterload (decreases stroke volume), end-systolic volume (ESV) volume remaining after ejection, myocardium responsible for contractile force, right atrium receives blood from all except pulmonary veins, P wave (atrial depolarization), mitral valve has two cusps (bicuspid), ductus arteriosus connects pulmonary trunk to aorta in fetal circulation, capillaries have highest total cross-sectional area, MAP = diastolic BP + 1/3 pulse pressure, norepinephrine increases heart rate, Frank-Starling law (stroke volume increases with end-diastolic volume), chordae tendineae not part of cardiac conduction system, Purkinje fibers have slowest intrinsic firing rate, tunica media contains smooth muscle and elastic fibers, pulse pressure calculation (150/90 = 60 mmHg), baroreceptors located in aortic arch and carotid sinuses, increased afterload decreases cardiac output, foramen ovale becomes fossa ovalis after birth, coronary sinus drains directly into right atrium, very high HR (180 bpm) decreases cardiac output due to decreased filling time, T wave represents ventricular repolarization, beta-1 agonist (positive inotrope), angiotensin II causes vasoconstriction and aldosterone release, pulse deficit (difference between apical and radial pulse rates), dicrotic notch corresponds to aortic valve closure, cardiac reserve (difference between resting and maximal CO), SA node as primary pacemaker, isovolumetric contraction begins immediately after AV valve closure, arteriolar vasodilation increases capillary hydrostatic pressure, diaphragm as principal inspiratory muscle, tidal volume (air moved during normal quiet breathing), Laplace’s law explains surfactant necessity, hypoventilation leads to hypercapnia and respiratory acidosis, medullary rhythmicity center sends signals via phrenic and intercostal nerves, highest PO2 in atmospheric air, increased CO2 shifts oxyhemoglobin curve right (Bohr effect), Type II alveolar cells secrete surfactant, intrapleural pressure is subatmospheric (negative), vital capacity = TV + IRV + ERV, forced exhalation uses internal intercostals and abdominal muscles, carotid bodies sense PO2 (and pH), pneumothorax causes loss of negative intrapleural pressure and lung collapse, residual volume (air remaining after maximal exhalation), Dalton’s law (total pressure = sum of partial pressures), hypoxic pulmonary vasoconstriction diverts blood from poorly ventilated to well-ventilated alveoli, CO2 transported primarily as bicarbonate (HCO3⁻), anatomic dead space ≈150 mL, pulmonary embolism increases A-a gradient, central chemoreceptors in medulla oblongata, restrictive lung disease (FEV1/FVC normal or increased), total lung capacity = VC + RV, V/Q mismatch occurs in exercise, PE, and normal lung, hypocapnia from hyperventilation, surfactant first produced around 24 weeks gestation, nephron as functional unit of kidney, collecting duct is impermeable to water without ADH, GFR regulated by both afferent and efferent arterioles, glucose completely reabsorbed in healthy kidneys, renin released by juxtaglomerular (JG) cells, aldosterone acts on distal tubule and collecting duct, ANP causes vasodilation and Na⁺ excretion, normal GFR ≈125 mL/min, micturition reflex integrated in sacral spinal cord (S2-S4), inulin clearance measures GFR (filtered, not reabsorbed or secreted), creatinine clearance overestimates GFR slightly due to tubular secretion, osmotic diuresis occurs with diabetes mellitus (glucosuria), countercurrent multiplier requires all (active NaCl reabsorption in thick ascending limb, water permeability of descending limb, vasa recta exchanger), maximum urine concentration ≈1200 mOsm/L, renal clearance = (U × V)/P, aldosterone increases K⁺ secretion, vomiting causes metabolic alkalosis (loss of gastric acid), angiotensin II causes vasoconstriction and aldosterone release, renal threshold for glucose ≈180 mg/dL, descending loop of Henle is impermeable to NaCl, polyuria with low specific gravity suggests diabetes insipidus, urea recycling from collecting duct to medullary interstitium, GFR 15 mL/min indicates renal failure (stage 5 CKD), glomerular filtration barrier excludes parietal layer of Bowman’s capsule, ADH increases water reabsorption without directly affecting Na⁺, salivary amylase begins starch digestion, CCK stimulates gallbladder contraction and pancreatic enzyme release, pepsinogen secreted by chief cells, intrinsic factor necessary for vitamin B12 absorption, bile produced by liver, enterohepatic circulation (recycling of bile salts), long-chain fatty acids absorbed into lacteals (chylomicrons), secretin stimulates pancreatic bicarbonate secretion, major site of nutrient absorption is duodenum and jejunum, large intestine does NOT absorb monosaccharides, gastrin released by G cells (antrum), enterogastric reflex inhibits gastric emptying (fat in duodenum), defecation reflex initiated by rectal distension, trypsinogen activated by enterokinase, lactase is a disaccharidase (brush border), Kupffer cells are macrophages in liver, hepatic portal vein carries blood from digestive organs to liver, Meissner’s plexus in submucosa, migrating motor complex (MMC) occurs during fasting to clear debris, vitamin K is fat-soluble (requires bile), FSH in males targets Sertoli cells, luteal phase characterized by high progesterone and elevated BBT, spermatogenesis occurs in seminiferous tubules, LH surge triggers ovulation, acrosome contains hydrolytic enzymes, implantation normally in uterine fundus, hCG secreted by placenta (syncytiotrophoblast), Leydig cells produce testosterone, menstrual phase sheds functional layer due to low progesterone/estrogen, vagina is internal genitalia, bulbospongiosus constricts vaginal orifice, inhibin secreted by Sertoli cells (males) and granulosa cells (females), corpus luteum degenerates to corpus albicans, sperm stored and matured in epididymis, dartos and cremaster regulate testicular temperature, placenta produces estrogen, progesterone, and hCG, colostrum rich in IgA antibodies, menopause defined as 12 consecutive months without menstruation, gubernaculum guides testicular descent, prostate secretes alkaline fluid with citrate and PSA, cytotoxic T cells (CD8+) kill virally infected cells, lymphatic capillaries have overlapping endothelial cells (one-way flaps), thymus is primary lymphoid organ, spleen red pulp removes old RBCs and filters blood, MHC II presents antigens to CD4+ helper T cells, IgM first immunoglobulin in primary response, passive immunity via maternal antibodies across placenta, alternative complement pathway activated by pathogen surface molecules (LPS), NK cells kill via perforin/granzymes, ADCC, and missing self MHC I, IL-1 and TNF-α cause fever, thoracic duct drains lymph from entire body except right upper quadrant, C5a is chemotactic factor for neutrophils, memory T cells enable faster/stronger secondary response, LPS is a PAMP, HIV targets CD4+ helper T cells, obstructive disease shows low FEV1/FVC ratio, ketones in urine suggest starvation or DKA, hypersegmented neutrophil (≥5 lobes) indicates megaloblastic anemia (B12/folate deficiency), normal QTc 440 ms (males) and 460 ms (females), anaphylaxis mediated by IgE and mast cell degranulation, leads II, III, aVF view inferior wall, renin released in response to low BP, low Na⁺, or sympathetic stimulation, left shift = increased immature neutrophils (bands), hepatic portal system carries blood from digestive tract to liver, popliteal pulse palpated behind knee in popliteal fossa. Suitable for BIOS 255 final exam preparation, A&P III students, and nursing/pre-med review.