Final answer:
Both the sympathetic and parasympathetic divisions of the autonomic nervous system impact GI motility through their opposing actions on the enteric neurons and interstitial cells of Cajal, with the sympathetic decreasing and the parasympathetic increasing motility. The correct option is C.
Step-by-step explanation:
The autonomic nervous system, composed of the sympathetic and parasympathetic divisions, plays a crucial role in regulating the motility of the gastrointestinal (GI) tract by impacting the interstitial cells of Cajal.
The sympathetic nervous system, when activated, initiates the fight-or-flight response which decreases GI motility by restricting the activity of enteric neurons. In contrast, the parasympathetic nervous system, associated with the rest-and-digest response, stimulates enteric neurons, thereby increasing GI secretion and motility.
The interplay between these two systems determines the overall motility of the GI tract. Therefore, the correct answer would be (c) Both sympathetic and parasympathetic impact motility, as both divisions of the autonomic nervous system have significant effects, though generally in opposite directions.