Stretching of the bladder reflexively causes all of the following EXCEPT
A) excitation of sympathetic neurons, causing the internal urethral sphincter to relax.
B) inhibition of somatic neurons to the external urethral sphincter, causing the sphincter to open.
C) micturition.
D) excitation of parasympathetic neurons, causing the detrusor muscles to contract.
E) opening of the urethral sphincters.

Question

Quizplus · Accepted Answer

Stretching of the bladder triggers the micturition reflex, which involves the excitation of parasympathetic neurons leading to detrusor muscle contraction (D), inhibition of somatic neurons to relax the external urethral sphincter (B), and ultimately results in micturition (C) and opening of the urethral sphincters (E). However, it does not cause the excitation of sympathetic neurons to relax the internal urethral sphincter; instead, sympathetic activity generally helps to keep the internal urethral sphincter contracted to retain urine.

Stretching of the Bladder Reflexively Causes All of the Following