During defecation,
A) distension in the rectal wall activates a short reflex.
B) distension in the rectal wall activates a spinal reflex.
C) the internal anal sphincter contracts.
D) the internal anal sphincter is consciously relaxed.
E) the external anal sphincter contracts.

Question

Quizplus · Accepted Answer

Distension in the rectal wall activates a spinal reflex, which results in the relaxation of the internal anal sphincter and contraction of the rectum and external anal sphincter. The external anal sphincter can be consciously relaxed to allow for defecation to occur.

During Defecation