Pathophysiology Renal 2

Question Answer major function of the proximal tubule Na reabsorption Two hormones that enhance Na absorption at the proximal tubule angiotensin II and Norepinephrine What DECREASES Na+ reabsorption of Na at the proximal tubule Dopamine This part of the nephron regulates the concentration of urine Loop of Henle This part of the nephron absorbs ~65-75% of the ultrafiltrate formed in bowmans capsule Proximal Tubule This part of the nephron usually reabsorbs 15 – 20% of the filtered Na+ Loop of Henle *** T/F – The ascending loop of henle is permeable to water false – ascending loop is impermeable to water All loop diuretics inhibit ______ in the _____ (what part of the nephron) Na and Cl reabsorption, thick ascending loop of henle In this part of the nephron, final adjustments on are made on the urine – pH, osmolality, and ionic composition, depending on the bodys needs Distal convoluted tubule (DCT) The DCT accounts for only about ____ % reabsorption of the filtered sodium load 5% in the DCT, ______ (what hormone) increases Ca++ reabsorption parathyroid hormone The collecting duct reabsorbs about ____ % of the filtered sodium load 5% what three hormones are working in the DCT parathyroid hormone, aldosterone, and ADH (vasopressin) What three hormones are working in the Collecting Duct ADH, ANP, Aldosterone What does atrial natiuretic peptide (ANP) do? inhibits water and sodium reabsorption Defintion: Specialized segment of the afferent arteriole that contains juxtaglomerular cells within its wall Juxtaglomerular Apparatus Definition: The end of the thick ascending cortical segment of the loop of Henle macula densa Juxtaglomerular cells contain the enzyme ____ and are innervated by the ____. renin, sympathetic nervous system (?1 receptor) controls blood flow into the glomerulus which will control and determine glomerular filtration Juxtaglomerular Apparatus 3 things that get renin released B1 sympathetic stimulation, changes in afferent arteriolar wall pressure (decrease), osmolarity in DCT (drop) ***what is it that actually stimulates the JG cells to secrete renin macula densa ***Renin released -> acts on _____ which forms _____ -> this is converted in the lungs to _____ -> which leads to the release of ____ (2 hormones) angiotensinogen, angiotensin I, angiotensin II, Aldosterone & ADH angiotensin II is a vaso_____ (constrictor/dilator) vasoconstrictor Definition: volume of blood filtered across the glomerulus per unit of time GFR Best single measure of kidney function GFR GFR is increased by increased renal blood flow, dilation of afferent arteriole, increased resistance of efferent arteriole GFR is decreased by constriction of afferent arteriole, decreased resistance in efferent arteriole autoregulation of renal blood flow happens between what MAP ranges 75 – 160 at what pressure would glomerular filtration cease <50 mmHg T/F – PNS is not physiologically significant in the renal system true T/F – SNS innervates only the afferent arteriole false – both afferent and efferent Increase in tubular flow tends to _____ (decrease/increase) GFR. Decrease in tubular flow tends to _____ (decrease/increase) GFR. _____ appears to be responsible. decrease, increase, macula densa Decrease in afferent arterial pressure stimulates _____ release renin Renal Failure: This category happens because of interruption of blood flow because of illness or injury prerenal Renal Failure: This category is due to direct damage by inflammation, toxins, drugs, or reduced blood supply intrarenal Renal Failure: This category is due to sudden obstruction of urine flow due to enlarged prostate, kidney stones, bladder tumor, or injury postrenal Liver failure would cause BUN to ____ (decrease/increase) decrease Burns, steroids, antibiotics, GI bleeding would cause BUN to _____ (decrease/increase) increase normal BUN levels 7-20 mg/dl BUN < 7 would have what causes (2) overhydration, decreased urea production (malnutrition, liver disease) BUN > 20 would have what causes (4) dehydration, increased protein (high protein diet, GI bleed, hematoma breakdown), catabolism (trauma, sepsis), decreased GFR BUN > 50 would have what causes (1) decreased GFR ***Creatine is produced by _____ muscle breakdown ***The most useful indicator of GFR Creatinine Clearance More muscle would have an _____ (decrease/increase) in creatinine clearance. Lean muscle would have an _____ (decrease/increase) in creatinine clearance. More, Less You need a _____ % reduction in GFR to see a _____ % increase in creatinine clearance 50, 100 what two drugs cause an increase in Creatinine Cimetidine, Trimethoprim Prerenal failure ratio of BUN:Cr 20:1 Renal failure ratio of BUN:Cr 15:1 Normal ratio of BUN:Cr 10:1