Does stimulation of the parasympathetic portion of the autonomic nervous system increase or decrease intestinal motility?

The correct answer indicates that stimulation of the parasympathetic portion of the autonomic nervous system increases intestinal motility. The parasympathetic nervous system is primarily responsible for promoting "rest and digest" activities, which includes enhancing and regulating digestive functions. When the parasympathetic system is activated, it releases neurotransmitters such as acetylcholine that act on various organs, including the intestines.

This stimulation leads to increased peristalsis, which is the rhythmic contraction of the intestinal muscles that propels food through the gastrointestinal tract. Additionally, it promotes the secretion of digestive enzymes and increases blood flow to the digestive organs, all of which work together to facilitate the digestive process and help with the absorption of nutrients.

Thus, the enhancement of intestinal motility through parasympathetic stimulation is vital for efficient digestion and nutrient assimilation. Understanding this relationship is important for veterinary pharmacology, as various medications may either stimulate or inhibit these processes in animals.