System
Purpose:
- Renin is released by granular cells in kidney
- cleaves angiotensinogen into angiotensin 1
Renin
Angiotensin 1
Angiotensin 2
- Angiotensin II constricts both arterioles. But efferent arterioles have higher sensitivity to Angiotensin II.
- At low dosage, it constricts efferent arterioles, thus raises glomerular hydrostatic pressure while reducing renal blood flow.
- At high dosage, it constricts both.
Aldosterone
- Made in the adrenal cortex
- Targets DCT
- Increases reabsorption of sodium
- Decreases plasma potassium, and hydrogen
- Released when low Na+, low blood volume, high K+ or acidosis