Week 10 Flashcards
what are the end results of the RAAS system?
- Vasoconstriction
- Kidney retains more water (increased volume)
- Activates pituitary gland to release ADH (anti diuretic hormone and acts on vasoconstriction and kidney)
- activates adrenal gland to release aldosterone (works on kidneys to retain fluid)
How do ACE inhibitors work?
Prevents the angiotensin converting enzyme from acting to convert angiotensin I to angiotensin II
A2 acts as a vasoconstrictor and also signals the adrenal cortex to create aldosterone (both which act to increase BP)
without this BP drops.
How do calcium channel blockers work?
Block the calcium ion gated channels in vessels walls and the heart which usually increase contractility and constrict.
With these blocked the vessels dilate and Heart contractility decreases.
How do Angiotensin 2 receptor antagonists work?
Blocks the receptors that angiotensin 2 binds to by acting as an antagonist, preventing vasoconstriction and the formation of aldosterone
How do Diuretics work?
signal the kidneys to release more sodium and water, reducing blood volume, reducing BP
How do beta blockers work?
Beta receptors increase heart rate and contractility and also vasoconstriction smooth muscle cells.
Beta blockers are antagonists which block these signals from transmitting
How to Nitrates work?
Nitrates are strong vasodilators, reducing resistance , reducing pre load and afterload and reducing BP
How to alpha blockers work?
alpha receptors are vasoconstrictors, alpha blockers antagonise receptor sites preventing the signal from transmitting