Search results
Results from the WOW.Com Content Network
The female or male external sphincter muscle of urethra (sphincter urethrae): located in the deep perineal pouch, at the bladder's distal inferior end in females, and inferior to the prostate (at the level of the membranous urethra) in males. It is a secondary sphincter to control the flow of urine through the urethra.
Following filtration of blood and further processing, wastes (in the form of urine) exit the kidney via the ureters, tubes made of smooth muscle fibres that propel urine towards the urinary bladder, where it is stored and subsequently expelled through the urethra during urination. The female and male urinary system are very similar, differing ...
The urethra (pl.: urethras or urethrae) is the tube that connects the urinary bladder to the urinary meatus, [1] [2] through which placental mammals urinate and ejaculate. [3] In non-mammalian vertebrates, the urethra also transports semen but is separate from the urinary tract.
This is the primary muscle for maintaining continence of urine, a function shared with the external urethral sphincter which is under voluntary control. It prevents urine leakage as the muscle is tonically contracted via sympathetic fibers traveling through the inferior hypogastric plexus and vesical nervous plexus. [4]
During urination, the detrusor muscle contracts, the external urinary sphincter and muscles of the perineum relax, and urine flows through the urethra [13] and exits the penis or vulva through the urinary meatus. [11] The urge to pass urine stems from stretch receptors that activate when between 300 - 400 mL urine is held within the bladder. [13]
Urination is the release of urine from the bladder to the outside of the body. Urine is released through the urethra and exits the penis or vulva through the urinary meatus in placental mammals, [1] [2]: 38, 364 but is released through the cloaca in other vertebrates.
The detrusor muscle remains relaxed to allow the bladder to store urine, and contracts during urination to release urine. Related are the urethral sphincter muscles which envelop the urethra to control the flow of urine when they contract.
The internal urethral orifice is the opening of the urinary bladder into the urethra. [1] Anatomy. It is usually somewhat crescent-shaped. [citation needed]