Functions of the Renal System
Objective 1
Describe the general functions of the urinary system. List the organs of the urinary system and identify their locations.
The renal system is not simply a urinary system (although it’s often called that). It’s not only a waste-removal system; it plays a vital role in maintaining homeostasis. The urinary system assists in controlling the body’s pH, electrolytes, fluid volume, and fluid concentration. The kidneys also produce hormones to regulate red blood cell production and blood calcium levels. A dysfunctional urinary system will have effects on all other systems of the body.
The renal system consists of the kidneys, ureters, bladder, and urethra. The kidneys are positioned in the abdominal cavity between the posterior abdominal wall and the peritoneum. Because only the anterior aspect is covered by the peritoneum, they are said to be retroperitoneal. The kidneys are located in the area of the inferior thoracic vertebrae (T11- T12) and the superior lumbar vertebrae (L1-L2). They are partially protected by the floating ribs (11-12). Because the liver takes up so much space on the right side, the right kidney is slightly lower than the left.
Extending from each kidney is a ureter. The ureter is a tube, which connects the kidney and the bladder and is also retroperitoneal. Both ureters drain into the bladder.
The bladder is a hollow, distensible organ in the pelvic cavity, designed to hold urine until it is voided. The bladder can hold an average of 700-800 ml of urine.
Media Attributions
- U19-001 Overview of Urinary Functions Table © Price, Travis is licensed under a CC BY-SA (Attribution ShareAlike) license
- U19-002 Position of Urinary System © Barnett, Cierra Memphis is licensed under a CC BY-NC-ND (Attribution NonCommercial NoDerivatives) license
- U19-003 horizontal section through kidneys © Anatomist90 is licensed under a CC BY-SA (Attribution ShareAlike) license
- U19-004 Urinary System © BruceBlaus adapted by Jim Hutchins is licensed under a CC BY-SA (Attribution ShareAlike) license