RAAS

Question 1

What factors increase renin release?

Answer 1

low arterial BP
low BP in glomerular vessels
increased loss of sodium, water
increased sympathetic activity

Question 2

What factors decrease renin release?

Answer 2

Na, water retention
increased BP
activation of angiotensin 1 receptors

Question 3

What are the 3 pathways that control renin secretion?

Answer 3

macula densa pathway
intrarenal baroreceptor pathway
beta-receptor pathway

Question 4

What is the macula densa?

Answer 4

specialised tubular area that marks the transition from the ascending loop of Henle to the distal tubule lying in direct contact with the vascular pole of the glomerulus from which it originated

Question 5

Physiological factors modifying renin release

Answer 5

systemic BP
dietary salt intake
pharmacological agents - NSAIDs (decreased renin release), loop diuretics (increased renin release), ACE-i/ARB (renin inhibitors)

Question 6

Effects of angiotensin 2

Answer 6

arterioles - vasoconstriction
kidney - stimulates sodium reabsorption
sympathetic nervous system - increased noradrenaline release
adrenal cortex - stimulates aldosterone release
hypothalamus - increases thirst sensation and ADH release

Question 7

Where is aldosterone produced?

Answer 7

zona glomerulosa of adrenal cortex

Question 8

When should ACE-inhibitors not be given?

Answer 8

bilateral renal artery stenosis
often withheld in AKI