Migrating motor complex

Migrating Motor Complex

File:Gastrointestinal tract.svg

Illustration of the human gastrointestinal tract

The Migrating Motor Complex (MMC) is a pattern of electrical activity that occurs in the gastrointestinal tract in a regular cycle during fasting. It was first described by Vantrappen et al. in 1977. The MMC is responsible for the rumbling experienced when hungry and is also thought to serve a "housekeeping" role and sweep residual undigested material through the digestive tube.

Phases

The MMC operates in a cycle that is usually about 90 to 120 minutes long and is divided into four phases:

1. Phase I: A period of quiescence during which there are few contractions.
2. Phase II: A period of intermittent contractions due to irregular neural activity.
3. Phase III: A period of regular contractions due to maximum neural activity. This is also known as the "housekeeper wave".
4. Phase IV: A short period of transition between phases III and I.

File:MMC Phases.png

Phases of the Migrating Motor Complex

Regulation

The MMC is regulated by several hormones and neurotransmitters, including motilin, serotonin, and ghrelin. Motilin is the primary hormone responsible for the initiation of the MMC.

Clinical Significance

Disruption of the MMC can lead to a variety of gastrointestinal disorders, such as gastroparesis, small intestinal bacterial overgrowth (SIBO), and irritable bowel syndrome (IBS).

See Also

• Gastrointestinal physiology
• Motilin
• Ghrelin

References

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