Low Blood Pressure | High Blood Pressure | Low Blood Osmolarity | High Blood Osmolarity | |
Low GFR | High GFR | |||
Where detected? | Stretch receptors in aorta and carotid artery AND Macula densa in DCT | Stretch receptors in aorta and carotid artery | Osmoreceptors in hypothalamus | Osmoreceptors in hypothalamus |
Action | Hypothalamus to release ADH AND release of renin à angiotensin + aldosterone | Hypothalamus to inhibit ADH release | Inhibit ADH release | Stimulate ADH release |
Kidney effects | ↑ GFR (vasoconstriction by angiotensin) ↑ Na+ absorption (aldosterone) | ↓ H2O permeability in DCT and collecting duct ↑ urine volume | ↓ H2O permeability in DCT and collecting duct ↑ urine volume | ↑ H2O permeability in DCT and collecting duct ↓ urine volume |
Blood effects | ↑ BP Vasoconstriction | ↓ BP | ↑ blood osmolarity | ↓ blood osmolarity |
Thirst | ↑ | ↓ | ↓ | ↑ |
Stretch receptors- how they work
baroreceptors
stretch receptors in carotid artery - aorta
REMEMBER
renin released in the kidneys and dumped into the blood system (afferent arteriole)
starts cascade of converting angiotensinogen into angiotensin