What physiological processes affect blood pressure?

Answer 1

1) Heart - The heart can increase or decrease your body's blood pressure by changing its heart rate or contractility. Increases in heart rate and contractility leads to more blood pumped out of the heart, and thus increase your blood pressure. Beta blockers such as Toprol can be used to decrease the heart rate and contractility, lowering the blood pressure.

2) Kidneys - The kidneys control the amount of fluid and salt excretion and retention. Low perfusion of the renal arteries or low salt concentration in the blood can lead to the release of Renin, which activates a cascade that results in increased water and salt retention, thus increasing the blood pressure. This process is often targeted by many anti-hypertensive medications such as HCTZ and Aldactone diuretics, and ACE inhibitors.

3) Blood vessels - Arterioles can either constrict or dilate. Increasing the constriction of vessels leads to increased resistance in blood flow. This can lead to increases in blood pressure. Control of this process is through neural regulation such as sympathetic neuron firing, and angiotensin II hormonal regulation. This can be controlled by medications such as Ca channel blockers like nifedipine, ACE inhibitors, and in the case of an older male with BPH, alpha blockers such as prazosin.