The external urethral sphincter surrounds the external urethral orifice. is composed of smooth muscle fibers. opens before the internal urethral sphincter during the micturition reflex. is controlled by the somatic nervous system. All of the choices are correct.

The correct answer is: is controlled by the somatic nervous system.

Explanation:

The urethra is an organ that is part of the urinary system, and consists of a tube that connects the urinary bladder to the urinary meatus, which is important for the excretion of urine. The urethra has two sphincters, which are muscles with the function to control the exit of the urine: the internal urethral sphincter and the external urethral sphincter.

The external urethral sphincter, unlike the internal one that is composed of smooth muscle, is made of skeletal muscle and is controlled by the somatic nervous system - this is what makes urination voluntary. Being the most external sphincter, it opens after the internal urethral sphincter during the micturition reflex.

Any damage in either sphincter can produce incontinence.

atp is used for energy.