Final answer:
The enteric nervous system, a part of the Peripheral Nervous System, is responsible for GI motility and works in conjunction with parts of the autonomic nervous system to control digestive processes.
Step-by-step explanation:
The part of the nervous system that carries out GI motility is the enteric nervous system (ENS), which is responsible for controlling the smooth muscle and glandular tissue in your digestive system. Although the enteric nervous system is a large part of the Peripheral Nervous System (PNS) and functions independently of the Central Nervous System (CNS), it is often considered a part of the autonomic nervous system due to its role in autonomically regulating digestion. The myenteric plexuses within the nervous tissue of the digestive tract influence digestive function; for instance, when stretch receptors in the stomach are activated, they can cause smooth muscle contraction in the stomach wall via a short reflex, which doesn't require CNS involvement. This response is facilitated by postganglionic parasympathetic neurons, which can be influenced by fibers in the vagus nerve.