B. Significant structures<\/p>\n
1. Cortex<\/strong><\/p>\n Outer area<\/em><\/p>\n 2. Medulla<\/strong><\/p>\n Inner area<\/em><\/p>\n Comprised of renal pyramids [8-18]\n 3. Renal pelvis<\/p>\n Area collecting urine and emptying it into ureter<\/em><\/p>\n 4. Microstructure<\/p>\n a. Nephron<\/strong>–<\/em><\/strong>\u00a0<\/em><\/strong>functional unit of kidney<\/em><\/strong><\/p>\n 1. Glomerulus<\/strong><\/p>\n Network of permeable blood capillaries that are fenestrated<\/em><\/p>\n a. Cortex<\/p>\n b. Afferent & efferent arterioles<\/p>\n c. Slits; Pores<\/p>\n 2. Renal tubules<\/p>\n a. Glomerular capsule\u00a0<\/strong>(Bowman’s) [cortex]\n – Renal corpuscle\u00a0= glomerulus plus glomerular capsule<\/em><\/p>\n b. Proximal convoluted tubule\u00a0<\/strong>[cortex]\n c. Descending limb of loop of nephron\u00a0<\/strong>(Henle)<\/p>\n d. Loop of nephron<\/strong><\/p>\n e. Ascending limp of lo<\/strong>op of nephron<\/strong><\/p>\n f. Distal convoluted tubule\u00a0<\/strong>[cortex]\n g. Collecting tubule<\/strong><\/p>\n C. Nephron physiology<\/p>\n 1. Glomerular filtration\u00a0<\/strong>[45 gal.\/day of filtrate, but you urinate 2-4 pts\/day ]\n a. Definition<\/p>\n Passive process, materials move out of glomerulus into capsule<\/em><\/p>\n b. Net filtration pressure:<\/p>\n Filtration Pressure = Glomerular blood pressure – [Capsular pressure + Colloid osmotic pressure]\n 1. Glomerular blood pressure in kidney capillaries [60 mmHg is the approximate glomerular blood pressure which is nearly double that of a regular blood capillary] this favors filtration<\/em><\/p>\n 2. Capsular pressure\u00a0This is the pressure in the Glomerular Capsule that is receiving whatever is filtered out of the blood.\u00a0 It is the\u00a0<\/em>push of fluids from the capsule, opposes filtration<\/em><\/p>\n 3. Colloid osmotic pressure\u00a0This is the substances (such as albumin proteins) in the blood that tend to draw fluids back into the glomerular capillaries.\u00a0 It is primarily\u00a0<\/em>unfiltered plasma proteins that oppose filtration<\/em><\/p>\n 2. Tubular Reabsorption & Secretion<\/strong><\/p>\n a. Proximal Convoluted Tubule<\/p>\n 1. Permeable to solutes and they are reabsorbed from kidney tubules to the bloodstream.\u00a0 (glucose, amino acids, organic molecules, Na, Ca, Cl, Vitamins);<\/p>\n 2. They are nearly all reabsorbed (active)<\/p>\n 3. Permeable to water; it’s reabsorbed<\/p>\n (passive), 65% decrease in volume<\/p>\n 4. Tubular secretion [H+<\/sup>, K+<\/sup>]\n b. Descending limb of loop of nephron<\/p>\n 1. Relatively impermeable to solutes<\/p>\n 2. Permeable to water, it’s reabsorbed<\/p>\n 3. Interstitial gradient promotes water reabsorption<\/p>\n c. Loop of nephron (permeable to urea)Urea is recycled<\/em><\/p>\n d. Ascending limb of loop of nephron<\/p>\n 1. Permeable to NaCl; it’s reabsorbed<\/p>\n 2. Impermeable to water<\/p>\n e. Distal convoluted tubule<\/p>\n 1. Aldosterone & ADH (anti-diuretic hormone)<\/p>\n <\/p>\n 2. Secretion (H+<\/sup>, NH3<\/sub>, drugs)<\/p>\n 3. Juxtaglomerular apparatus (renin & Erythropoietin precursor)<\/p>\n f. Collecting tubule\/ducts<\/p>\n 1. Aldosterone causes sodium reabsorption<\/p>\n 2. ADH causes water reabsorption<\/p>\n 3. Urea<\/p>\n 3. Vasa recta<\/p>\n Countercurrent thin walled blood vessels serving tubules<\/em><\/p>\n a. Maintains interstitial concentrations<\/p>\n b. Aids in concentrating urine<\/p>\n c. Absorbs some H2<\/sub>O<\/p>\n \u00a0 \u00a0 \u00a0The figure below explains all of the notes above on kidney physiology.\u00a0 Study it\u00a0 \u00a0 \u00a0thoroughly.<\/p>\n I. The Mammalian Kidney A. Overall function – homeostasis Controls composition & volume of blood, excretes waste, helps to regulate blood pressure, erythropoiesis, and activate vitamin D B. Significant structures 1. Cortex Outer area 2. Medulla Inner area Comprised of … Continue reading ![\"nephron\"](\"http:\/\/sites.msudenver.edu\/haysc\/wp-content\/uploads\/sites\/150\/2015\/08\/nephron.jpg\")
<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"