Small Intestinal Motility
| Overview |
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- Motility of the small intestine allows ingested foods to be mixed with digestive fluids, exposes foods to the small intestine mucosa for absorption, and moves the foods along the length of the intestine. The small intestine displays both peristaltic and mixing patterns of contractions as described in GI Motility Patterns.
| Regulation |
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- Contractions in the small intestine are controlled by the myenteric plexus and occur with a regular rhythmicity determined by the 'Slow Waves' described in Electrical Basis of GI Rhythmic Contractions. However, as explained in on that page, the autonomic nervous system can modulate slow waves such that the sympathetic nervous system generally reduces motility while the parasympathetic nervous system generally increases motility.
| Ileocecal Valve and Sphincter |
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- Between the small intestine and the large intestine lie the ileocecal valve and ileocecal sphincter. The valve prevents backflow of contents from the colon into the ileum while the ileocecal sphincter can regulate the emptying of the ileum into the cecum. The ileocecal sphincter generally remains closed if there is irritation or distension in the cecum and generally opens after a meal.