What part of the nervous system primarily increases GI movement?

The parasympathetic nervous system is primarily responsible for increasing gastrointestinal (GI) movement. This part of the autonomic nervous system is often referred to as the "rest and digest" system. When activated, the parasympathetic nervous system stimulates various digestive processes such as increasing peristalsis (the rhythmic contractions that move food through the GI tract), enhancing secretion of digestive enzymes and fluids, and improving blood flow to the digestive organs.

During rest and after feeding, the activation of the parasympathetic pathways promotes efficiency in digestion and nutrient absorption, ensuring that food is processed effectively within the gastrointestinal tract. This contrasts with the sympathetic nervous system, which tends to inhibit digestive activities and divert energy toward "fight or flight" responses.

The central nervous system is involved in higher-level integration and overall control of the body, but it does not specifically drive GI movement as it relates to digestion. The enteric nervous system, while it plays a significant role in regulating GI functions independently, is influenced by inputs from the parasympathetic nervous system that enhance its activity, working in concert with it rather than acting as the primary driver of increased GI movement.