The urethra is a tube which conducts the urine from the urinary bladder to
the outside of the body. It begins at the anterior base of the urinary bladder.
a. Urethral Sphincters. The urethral sphincters are circular muscle
masses which control the passage of the urine through the urethra. There are two urethral
sphincters--an internal urethral sphincter and an external urethral sphincter.
(1) The internal urethral sphincter is located in the floor of the urinary
bladder. It is made of smooth muscle tissue. It is controlled by nerves of the autonomic
nervous system (lesson 11).
(2) The external urethral sphincter is more inferior around the urethra in
the area of the pelvic floor. It is made up of striated muscle tissue. It is controlled by
the peripheral nervous system (lesson 11).
b. Male-Female Differences. The female urethra is short and direct.
The male urethra is much longer and has two curvatures. Whereas the female urethra serves
only a urinary function, the male urethra serves both the urinary and reproductive
functions.
Primary Content Providers: The U. S. Army, The
U.S. Navy
Ancillary Content and Online Version: David L. Heiserman
Publisher: SweetHaven Publishing Services
