Renal system physiology

This course is a part of NCLEX-RN, a 21-course Topic series from Khan Academy.

If you want to learn more about the renal system, then urine the right place (pun intended)! Every thirty minutes, your kidneys filter you entire blood supply and remove toxic wastes. These paired organs are key to maintaining electrolyte and water homeostasis in your body.

This course contains 2 segments:

Renal system introduction

3B: If you want to learn more about the renal system, then urine the right place! (Pun aside, the kidneys are about more than just making urine). Every thirty minutes, your kidneys filter the entire blood supply in your body. Imagine a dirty pool filled with algae. Placing a filter in this pool will cause the algae to be flushed out, and after a time you’ll have a clean, crisp blue pool to enjoy. Just like the filter for a pool, our kidneys filter the blood and remove toxic wastes. These paired organs are key to maintaining electrolyte and water homeostasis in your body.

Renal regulation of blood pressure

In addition to fluid and electrolyte balance, the kidneys play an essential role in regulating blood pressure. When the nephron, the functional unit of the kidney, senses that it is not receiving much blood flow, it knows something is up. So begins a cascade which allows the nephron to reabsorb more fluid from the urine, in attempt to fill up the perceived dip in blood volume. Here you will learn the mechanism of ADH and the renin-angiotensin-aldosterone system in sustaining this homeostasis.