Motility in the small intestine

The predominant form of contraction in small intestine is segmentation contraction. The most common movements seen in the small intestine when chyme is present are stationary contractions and relaxations of short segments of the small intestine. The presence of chyme in the small intestine distends the small intestinal wall; the stretch elicits/triggers local contractions and […]

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Motility in the stomach

As food leaves the esophagus into the stomach, stomach initially stores the food, and then mixes the food with stomach acid, pepsin, mucus and other gastric secretions to form a semi-fluid substance called chyme, after which stomach empties the chyme into the small intestine (duodenum) at a controlled rate suitable for adequate digestion and absorption […]

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The varying patterns of movements in the GI tract

The varying patterns of movements in the GI tract Three basic patterns of GI smooth muscle contraction exist. These are: Peristaltic contractions Segmentation contractions also called mixing contractions Migrating motor complex 1. Peristaltic contractions Peristaltic contractions are GI smooth muscle contractions that occur during or immediately after a meal. By way of definition, peristalsis refers […]

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Mastication and swallowing

Overview Digestive enzymes act only on the exposed surfaces of food particles, consequently, how fast digestion proceeds depends on the total surface area available to the digestive enzymes. Chewing is important because it breaks up large food particles and mixes the food with secretions of the salivary glands. This wetting and grinding of food to […]

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