Control of glomerular filtration and renal blood flow

Question 1

Control of glomerular filtration and renal blood flow – autoregulation

Answer 1

1 - MYOGENIC RESPONSE

ability for the renal blood vessels to maintain shape during changes in volume/ pressure

if blood pressure is too high
- afferent arterioles constrict
- smooth muscle contract
- less bloodflow to glomerulus

if blood pressure is too low
- afferent arterioles dilate
- smooth muscles relax
- more bloodflow to glomerulus

Question 2

Control of glomerular filtration and renal blood flow – autoregulation - 2

Answer 2

tubular-glomerular feedback

macula densa of juxtaglomerular apparatus
controls amount of NaCl in distal tubule

high NaCl
- afferent arterioles constrict
- prevent too much nacl flowing

low NaCl
- afferent arterioles dilate
- increases nacl flowing

Question 3

Control of glomerular filtration and renal blood flow - hormonal 1

Answer 3

RAAS

Question 4

Control of glomerular filtration and renal blood flow - 2

Answer 4

ANP

• released from atria of heart in response to increase blood volume
• causes vasodilation of afferent arteriole
• causes vasoconstriction of efferent arteriole
• inhibits RAAS to lower blood pressure/ volume

Question 5

Control of glomerular filtration and renal blood flow - 3

Answer 5

• body needs to conserve water
• ADH released from posterior pituitary gland
• ADH functions to activate aquaporins-2-channels onto collecting duct cell membrane
• ADH increases permeability of collecting duct to allow water to be reabsorbed from filtrate into bloodstream

aldosterone acts on DCT to increase sodium reabsorption

= concentrated urine formed
= high urine osmolarity

Question 6

Control of glomerular filtration and renal blood flow - 4

Answer 6

SNS
- beta adrenergic receptors + noradrenaline = vasoconstriction of afferent arterioles = renin release

PNS
- Ach + muscarinic receptors = vasodilation of afferent arterioles = renin inhibit