How are the kidneys involved in controlling blood volume? How is the volume of blood in the body related to arterial pressure?

Explanation

Renin- Angiotensin stimulates Nat reabsorption from the glomerular filtrate. This stimulates Adrenal cortex to secrete aldosterone that causes reabsorption of `Na^+, K^+ ` excretion and absorption of water. This reduces loss of water into the urine. This maintains the volume of blood. An increase in blood volume increases central venous pressure. This increases right atrial pressure, right ventricular end- diastolic pressure and volume. This increases ventricular stroke volume and cardiac output and arterial blood pressure.