External Urethral Sphincter is composed of which type of muscle?

External Urethral Sphincter is composed of which type of muscle?

• A. Smooth muscle
• B. Skeletal muscle
• C. Cardiac muscle
• D. Nervous tissue

Answer: (B)

The external urethral sphincter is composed of skeletal muscle, a voluntary striated muscle. This arrangement lets you consciously contract or relax it to control urination. It receives somatic innervation from the pudendal nerve (S2–S4), which is why you can deliberately hold urine or release it when you choose. In contrast, the internal urethral sphincter is smooth muscle and acts involuntarily under autonomic control to help maintain continence at rest. During urination, the detrusor muscle of the bladder contracts while the external sphincter relaxes, allowing urine to flow.

The external urethral sphincter is composed of skeletal muscle, a voluntary striated muscle. This arrangement lets you consciously contract or relax it to control urination. It receives somatic innervation from the pudendal nerve (S2–S4), which is why you can deliberately hold urine or release it when you choose. In contrast, the internal urethral sphincter is smooth muscle and acts involuntarily under autonomic control to help maintain continence at rest. During urination, the detrusor muscle of the bladder contracts while the external sphincter relaxes, allowing urine to flow.