Definition
noun
The urethral sphincter associated with the discharge of urine in both males and females, and where semen is ejected in males
Supplement
The urethral sphincters are the muscles that control the discharge of urine from the urinary bladder through the urethra. In males, they are also involved in controlling the exit of semen during ejaculation. There are two urethral sphincters: (1) internal urethral sphincter (i.e. the urethral sphincter that is at the proximal end of the urethra) and (2) external urethral sphincter.
The external urethral sphincter is a urethral sphincter muscle located at the distal inferior end of the urinary bladder in females and inferior to the prostate in males. It is associated with the discharge of urine in both males and females and in the exit of semen in males. This sphincter controls the flow of urine through the urethra.
While the internal urethral sphincter is made up of smooth muscle, the external urethral sphincter is made up of skeletal muscle. Thus, the external urethral sphincter is associated with voluntary movement and autonomic control.
Synonym(s):
- sphincter urethrae
- musculus sphincter urethrae
- Guthrie’s muscle
- musculus constrictor urethrae
- musculus sphincter urethrae membranaceae
- musculus compressor urethrae
- sphincter Muscle of urethra
- Wilsons muscle
See also:
