The human bladder is part of the urinary system that eliminates liquid waste from the body. It consists of the kidneys, two ureters, different muscles types, bladder nerves, a bladder and a urethra. The urinary system performs its work without any conscious effort on your part.
TL;DR (Too Long; Didn't Read)
TL;DR (Too Long; Didn't Read)
The human bladder looks like a triangular-shaped pear when empty inside an adult body and stretches to store liquid waste called urea, which is extracted from the blood by the kidneys and stored in the bladder as urine.
Urinary System and Bladder Quick Facts
- The kidneys generate urine every 10 to 15 seconds.
- Ligaments hold the bladder in place in the pelvic system.
- Ring-like muscles called sphincters keep the bladder closed to store urine.
- The bladder expands and contracts as it fills and empties.
- A healthy adult bladder can store up to 16 ounces (455 milliliters) of urine for between two to five hours.
- The nerves in the bladder automatically let you know when the bladder requires emptying.
- Muscles contract to expel urine during urination as sphincter muscles in the urethra relax.
- Healthy urine appears light yellow or the color of straw.
- Dark or honey-colored urine indicates you are not drinking enough water, and brown-colored urine could indicate a health problem.
- Pink urine indicates the presence of blood and a much-needed visit to the doctor.
Human Bladder Size and Location
The human bladder is a hollow, muscular sac consisting of smooth muscle and a mucosal covering, which sits in the pelvis area of both men and women. Bladder size in adults is equivalent to a pear in both size and shape. The bladder location and construction allow it to store urine until released through urination. Layers of muscle tissue line the bladder, allowing it to stretch as it fills up with urine. Bladder innervation refers to the parasympathetic and the sympathetic nerves in the bladder that control it.
These nerves respond without you having to think about them. The parasympathetic nerves cause the detrusor muscle to contract, the smooth muscle of the bladder sac and the sympathetic nerves affect the contraction of the urethral sphincter, a ring of muscle that keeps the bladder closed until you feel the need to urinate.
Urinary System and Bladder Function
After the body removes the nutrients from food, it must deal with the solid and liquid waste left over. Solid waste travels to the bowel system while the kidneys filter liquid waste from the blood. The liquid waste, called urea, leaves the kidneys via two long tubes – ureters – and enters the bladder, where these tubes attach to the trigone area – a thickened muscle at the back of the bladder. The urinary system also helps to maintain the balance between sodium, potassium and water in the body.
About the Author
As a journalist and editor for several years, Laurie Brenner has covered many topics in her writings, but science is one of her first loves. Her stint as Manager of the California State Mining and Mineral Museum in California's gold country served to deepen her interest in science which she now fulfills by writing for online science websites. Brenner is also a published sci-fi author. She graduated from San Diego's Coleman College in 1972.