Title study guides_Urinary.pdf ✅

URINARY SYSTEM revised 12 April 2016 S & M p. 703-, Martini’s 5th: 942-982, 6th: 971-1045, 7th: 952-1023, 8th: 966-1009, 9th: 954-, 10th: 972-987 Generates, maintains opt’m cond’ns (homeostasis) in body by selective retention, excretion. REGULATES plasma composition blood volume pH ionic concentration (electrolytes) EXCRETES variety of metabolic products: urea (21 g/d), uric acid (0.5 g/d), creatinine (1.8 g/d) (breakdown of muscles) First in anterior: mesonephros: pronephric duct drains (later: mesonephric duct) METANEPHROS: forms in 5th week, out pockets from mesonephric duct. cloaca develops into bladder ANATOMY: R kidney is lower than L due to liver, both retroperitoneal: (p 976 & 977) adipose capsule mass of perirenal fat (brown fat): cushion, collagen fibers support renal fascia: 2x layer (ant.= peritoneum), attaches to abdominal wall renal capsule layer of collagen fibers surround organ renal hilus medial indentation contains renal arteries, veins and ureter cortex extensions called renal columns pass into medulla (p. 977) arcuate arteries and veins separate the cortex from medulla medulla consists of renal pyramids, tips called papillae. minor and major calyces, renal pelvis receive and direct urine into ureter Ureter retroperitoneal, attached to rear abdominal wall Bladder derived from cloaca; urinary trigone; transitional epithelium; internal & ext. urinary sphincters Urethra mucous membrane, it and bladder lined with transitional epithelium. Urethritis KIDNEY FUNCTION: Three ways solutes in blood might be treated: 1) excrete, 2) discard part, 3) save NEPHRON STRUCTURE: functional unit of the kidney (p 978-979, 981) renal corpuscle combination of capsule and glomerulus bowman's capsule cup shaped, receives filtrate, parietal v visceral layer glomerulus 20% of blood becomes filtrate, pushed thru by heart filtration membrane:podocytes, filtration slits, fenestrated endothelium (“windowed”) pores thru which filtrate is passed proximal conv’d tbls (P 980)possesses microvilli, most solutes resorbed loop of Henle establishes salt gradient descending limb thin, permeable to water ascending limbthick, imperm. to water, Na/K pump Na+ out distal convoluted tubule ions saved/thrown (forms juxtaglomerular complex with afferent arteriole) collecting tubule water retained/thrown, osmolarity adjusted peritubular capillaries pick up saved solutes and water vasa recta surround loop of Henle, pick up water and NaCl FUNCTION: (p table 985- 987) All blood in body filtered 60x /day, 45 gallons filtrate produced, 1 to 11⁄2 gallons urine produced per day, released by micturition Water diffuses freely thru walls of nephron except: 1) ascending loop of Henle, 2) collecting duct in absence of antidiuretic hormone