Gastrointestinal motility

Gastrointestinal motility refers to the movements of the digestive system and the transit of the contents within it. It is a critical aspect of the digestion process, enabling the mixing of food with digestive juices and facilitating its progression through the system, from ingestion to excretion.

Overview

Gastrointestinal motility is primarily controlled by the nervous system and hormones, which regulate the muscles of the gastrointestinal tract. These muscles contract in a coordinated fashion to propel food through the esophagus, stomach, small intestine, and large intestine. The process of motility includes various types of movements such as peristalsis, segmentation, and mass movement.

Types of Movements

• Peristalsis - This is a series of wave-like muscle contractions that moves food to different processing stations in the digestive tract. It is the primary mechanism of motility in the esophagus and intestines.
• Segmentation - This movement primarily occurs in the small intestine and involves contractions of the circular muscles in the digestive tract, mixing the intestinal contents with digestive juices and increasing the absorption of nutrients.
• Mass Movement - This is a type of motility that generally occurs in the large intestine and is responsible for the movement of waste towards the rectum.

Regulation of Gastrointestinal Motility

The regulation of gastrointestinal motility involves intricate interactions between the enteric nervous system (ENS), the central nervous system (CNS), and various gastrointestinal hormones. The ENS, often referred to as the "second brain," contains as many neurons as the spinal cord and functions semi-independently in the gastrointestinal system.

• Neural Control - The ENS regulates local reflexes, and the CNS integrates higher level control.
• Hormonal Control - Hormones such as gastrin, cholecystokinin (CCK), and motilin play significant roles in controlling the rate and strength of gastrointestinal contractions.

Clinical Significance

Abnormalities in gastrointestinal motility can lead to various disorders, including gastroesophageal reflux disease (GERD), gastroparesis, and irritable bowel syndrome (IBS). These conditions can significantly impact quality of life and may require interventions ranging from dietary changes to medication and, in severe cases, surgery.

Diagnostic Techniques

To assess gastrointestinal motility, several diagnostic techniques may be employed:

• Manometry - Measures the pressure within the gastrointestinal tract.
• Scintigraphy - A radioactive imaging test that tracks a meal's progress through the digestive system.
• Smart pill - A capsule containing sensors that measure pH, temperature, and pressure as it travels through the gastrointestinal tract.

Treatment and Management

Treatment of motility disorders may include dietary modifications, pharmacological therapy, and in some cases, surgical interventions. Medications can include prokinetics and antispasmodics, which help to regulate or enhance motility.

See Also

• Digestive system
• Human gastrointestinal tract
• Neurogastroenterology