Long term control of blood pressure

Question 1

role of kidneys in regulating plasma volume and blood pressure

Answer 1

sodium transport builds up a conc gradient and modulates sodium transport which will affect how big the osmotic gradient is in the first place. making collecting duct very permeable to water will result in lots of water reabsorption, little urine and conserve plasma volume but making the collecting duct very impermeable to water will result in little reabsorption, lots of urine and a reduction in plasma volume

Question 2

what triggers renin production from juxtaglomerular cells

Answer 2

activation of sympathetic nerves to the juxtaglomerular apparatus, decreased distension of afferent arterioles (the renal baroreflex) and decreased delivery of sodium/calcium through the tubule. all of these are signs of low MAP

Question 3

atrial natriuretic peptide and brain natriuretic peptide is produced

Answer 3

in and released from myocardial cells in the atria and the ventricles respectively

Question 4

what does angiotensin II do

Answer 4

stimulates release of aldosterone from adrenal cortex, increases release of ADH from pituitary gland, is a vasoconstrictor

Question 5

effect of increasing ADH from pituitary gland

Answer 5

increases water permeability of collecting duct, reduces diuresis and increases plasma volume and increases sense of thirst

Question 6

effect of release of aldosterone from adrenal cortex

Answer 6

increases sodium reabsorption loop of henle and therefore reduces diuresis and increases plasma volume

Question 7

what does ADH do

Answer 7

increases permeability of the collecting duct to H20 therefore reduces diuresis and increases plasma volume also causes vasoconstriction which increases MAP

Question 8

what triggers release of ANP and BNP

Answer 8

increased distension of the atria and ventricles

Question 9

what do ANP and BNP do

Answer 9

increase excretion of sodium, Inhibit release of renin, act on medullary CV centres to reduce MAP