Online College Courses for Credit

Urinary System and Extracellular Fluid Homeostasis

Urinary System and Extracellular Fluid Homeostasis

Author: Aaron Mullally

This lesson will identify the role of the kidneys in maintaining homeostasis in extracellular fluids.

See More
Fast, Free College Credit

Developing Effective Teams

Let's Ride
*No strings attached. This college course is 100% free and is worth 1 semester credit.

46 Sophia partners guarantee credit transfer.

299 Institutions have accepted or given pre-approval for credit transfer.

* The American Council on Education's College Credit Recommendation Service (ACE Credit®) has evaluated and recommended college credit for 33 of Sophia’s online courses. Many different colleges and universities consider ACE CREDIT recommendations in determining the applicability to their course and degree programs.

Terms to Know
Bowman's Capsule

A section of a nephron where afferent arterioles deliver blood to the nephron for water and solutes to be filtered out.

Extracellular Fluid

Fluid of the body that is contained outside of cells. Plasma is an example of extracellular fluid outside of blood cells.


The first step in urine formation in which urine is filtered from afferent arterioles in the Bowman's capsule of a nephron.


A tangle of blood vessels in the Bowman's capsule where water and solutes are forced out of blood and into the Bowman's capsule to begin the next stage of urine formation.


Organs of the body that produce urine and help to regulate the composition and volume of body fluids.

Peritubular Capillaries

Capillaries associated with nephrons which allow water and solutes to be exchanged between the nephron and the blood during urine formation.


The second step in urine formation, in which valuable water and solutes are reabsorbed back into the blood.


The third step in urine formation in which filtrate moves toward collecting ducts; secretion helps maintain the body's acid-base balance.


A reflex that occurs when the urinary bladder fills to capacity and is stimulated to empty itself.


A substance formed by the kidneys and excreted from the body as a means to regulate the composition and volume of extracellular fluids.