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Segmentation and migrating motility complexes & Gastroileal reflex

By: HWC, Views: 7659

• Within a few hours, most of the stomach contents are in the duodenum. • Distension of stretch receptors in the small intestine activates a reflex that stimulates segmentation, a mixing movement. • During segmentation, sections of the intestine are constricted. • This movement incr...

Secretin (inhibiting gastric acid secretion), Cholecystokinin (fat digestion) & Cholecystokinin

By: HWC, Views: 7547

• As chyme approaches the small intestine, secretin also targets acid-producing parietal cells in the gastric mucosa. • Increased secretin inhibits gastric add secretion. • With less gastric acid produced, the chyme going into the intestine is less acidic. • The hormone CCK also reg...

Gastrin (gastric emptying) & Secretin (buffering gastric acid)

By: HWC, Views: 7240

• Gastrin also binds to the smooth muscle cells in the stomach causing: • Increased gastric motility. • Opening of pyloric sphincter. • Increased gastric emptying. • The intestinal phase of digestion begins as chyme enters the duodenum. • The chyme's acidity can damage int...

Stomach peristalsis & Enterogastric reflex

By: HWC, Views: 7130

• Food enters, distending the stomach. • Stretch receptors activate enteric reflexes that promote peristaltic movements. • These movements, called mixing waves, begin to mix the food with stomach secretions. • Mixing waves force the digesting food (chyme) toward and through the pylo...

Nucleic acid digestion -small intestine

By: HWC, Views: 7746

Nucleic acid digestion, which takes place in the small intestine, involves: • Pancreatic nucleases. • Brush-border enzymes in the small intestine. • Nucleic acids enter the small intestine dissolved in gastric chyme. • As gastric chyme enters the duodenum of the small intestine, p...

Haustral churning, Gastrocolic reflex and mass peristalsis & Defecation

By: HWC, Views: 7897

• As the cecum becomes filled and distends, a local reflex causes: • Closure of the ileocecal valve. • Activation of haustral churning. • Haustral churning mixes the chyme, which helps absorption of water, salts, and vitamins. • Haustral churning propels the contents of the colo...

Stomach peristalsis - Movement of Food Through the Small Intestine

By: HWC, Views: 7741

Peristalsis is a series of wave-like muscle contractions that moves food to different processing stations in the digestive tract. The process of peristalsis begins in the esophagus when a bolus of food is swallowed. The strong wave-like motions of the smooth muscle in the esophagus carry the food...

Lipid absorption - end products & transport mechanism

By: HWC, Views: 7249

• The end products, fatty acids and monoglycerides, depend on bile salts for absorption. • Bile salts form micelles (tiny spheres), which ferry fatty acids and monoglycerides to epithelial cells. • Free fatty acids, monoglycerides, and some phospholipids and cholesterol molecules, dif...

Protein digestion - stomach & small intestine

By: HWC, Views: 7188

• Protein digestion occurs in the stomach and small intestine. • The stomach enzyme pepsin initiates the process. • Pancreatic and intestinal brush border enzymes complete the digestive process. • In the stomach, pepsin is created from pepsinogen in the presence of pH-lowering hyd...