A condition called megacolon, which results from excess dilation of the colon proximal to a region of functional obstruction, would most likely be caused by
A)a great increase in parasympathetic activity in the local region.
B)a great increase in the level of sympathetic activity in the region.
C)too much activity in the sympathetic chain ganglia.
D)reduction of parasympathetic innervation in the region.
E)None of the answers are correct.

Question

Quizplus · Accepted Answer

Megacolon is a condition where there is excessive dilation of the colon proximal to a region of functional obstruction. Parasympathetic innervation is responsible for promoting peristalsis and contraction of the colon, so a reduction in parasympathetic innervation in the region would lead to a lack of movement in the colon, resulting in dilation and megacolon. Therefore, choice D is the best answer.

A Condition Called Megacolon, Which Results from Excess Dilation of the Colon