Gastrointestinal tract motility (GI motility)

Gastrointestinal tract motility is the coordinated contraction of smooth muscles within the walls of the gastrointestinal tract. These contractions mix and propel contents through the digestive system, facilitating digestion and absorption of nutrients while eliminating waste. The GI tract is divided into four distinct regions separated by sphincter muscles: the esophagus, stomach, small intestine, and colon, each with different motility patterns and functions. Motility is primarily controlled by the enteric nervous system (ENS), a specialized portion of the autonomic nervous system located within the walls of the GI tract, consisting of the myenteric (Auerbach's) plexus and submucosal (Meissner's) plexus. The interstitial cells of Cajal (ICC) act as pacemakers, generating spontaneous electrical activity called slow waves that coordinate smooth muscle contractions. Three main patterns of GI motility include: peristalsis (sequential contractions that propel contents forward), segmentation (mixing contractions), and the migrating motor complex (a pattern of contractions during fasting that cleans the GI tract). These patterns vary throughout different regions of the digestive system. Regulation of GI motility involves multiple mechanisms including neural control (via the ENS and central nervous system), hormonal regulation (through gastrointestinal peptides like gastrin, secretin, and motilin), and local factors. Smooth muscle cells form electrical and mechanical junctions between cells that facilitate coordination of contractions. Excitation-contraction coupling occurs through calcium entry via ion channels, leading to muscle contraction. Abnormal motility can lead to various disorders including GERD, gastroparesis, constipation, and diarrhea, which may cause symptoms such as abdominal pain, bloating, nausea, and vomiting.

Other names

Gastrointestinal motilityGI motilityGut motility

Not applicable (as this is a physiological process)