Kidney Flashcards
Renin triggers
- decreased blood pressure
- sympathetic nervous system innervation
- decreased [Na+] by the macula densa
Renin signaling from macula densa cells
Send prostaglandins to JG cells (which release renin)
Angiotensin pathway
Released into bloodstream by the liver, cut down to 10 AA by renin -> angiotensin 1 -> converted into angiotensin 2 by ACE
Angiotensin 2 effects
- Vasoconstriction in smooth muscle of arterioles, to increase resistance
- Na+ reabsorption -> H20 reabsorption
- Pituitary will release ADH
- Adrenal gland will secrete Aldosterone
Aldosterone source
Adrenal cortex
Aldosterone triggers
- angiotensin 2
2. K+ ions
Aldosterone effects
- Drives Na+/K+ pumps to work harder
- K+ channels put in to leak K+ into filtrate
- Puts in Na+ channels to move Na+ from uring to blood
- Na+ reabsorption drives H20 reabsorption
ADH source
Posterior pituitary (originates from hypothalamus)
ADH triggers
- Blood osmolarity (should be within 280-300 Osm/L range)
- Decreased blood volume (from neural receptors in right atrium)
- Decreased blood pressure via baroreceptors in aortic arch and carotid
- Angiotensin 2
ADH effects
- Smooth muscle contraction -> vasoconstriction
2. Act on kidneys to increase H20 reabsoption via aquaporins
Where does aldosterone have its effect
Late distal convoluted tubule and collecting duct
How does Aldosterone get rid of H+?
Drives 2 transporters between lumen and alpha-intercalated cells
1) H+ transports (requires ATP)
2) Na+/H+ antiporter (uses Na gradient)
What are the effects of the sympathetic nervous system on the renal system
- Vasoconstriction of afferent arterioles
2. The release of renin from juxtaglomerular cells
Excess sodium in urine
natriuresis
What causes the production of erythropoetin?
Low blood volume
