Manitoba Nephrology Nurse Practice Test

The kidneys play a crucial role in regulating blood pressure primarily through their ability to help retain water and sodium balance. When blood volume decreases, the kidneys can conserve sodium and water to maintain or increase blood volume, which in turn raises blood pressure. This physiological response is part of the renin-angiotensin-aldosterone system (RAAS), where the kidneys release the hormone renin in response to low blood pressure or low sodium levels. Renin initiates a cascade of reactions that result in vasoconstriction and increased retention of sodium and water, contributing to higher blood pressure.

This regulatory mechanism showcases the kidneys' significance in maintaining homeostasis and ensuring that blood pressure remains within a functional range. Their ability to adjust the amount of sodium and water helps manage overall blood volume, directly affecting how much blood is available to circulate through the body and exert pressure on blood vessel walls.