Which is true concerning the internal and external urethral sphincters?
A) The internal sphincter is involuntary smooth muscle and the external is voluntary striated muscle.
B) The internal sphincter is voluntary striated muscle and the external is involuntary smooth muscle.
C) Both are involuntary smooth muscle.
D) Both are voluntary striated muscle.

Question

Quizplus · Accepted Answer

The internal sphincter is made of involuntary smooth muscle and is controlled by the autonomic nervous system, while the external sphincter is made of voluntary striated muscle and is under conscious control.

Which Is True Concerning the Internal and External Urethral Sphincters