Intestinal Motility + Peristalsis

What are the main functions of intestinal motility?

Mixing, churning, and moving residue forward

What is one function of intestinal contractions related to digestion?

To mix chyme with the intestinal juice, bile, and pancreatic juice

Why is mixing chyme with intestinal fluids important

To neutralize acid

What is the purpose of churning chyme in the small intestine?

To bring churn chyme in contact with mucosa for digestion and nutrient absorption

What is the third function of intestinal motility?

To move residue toward large intestine

What is segmentation?

stationary constriction along intestines

Segmentation is the most common kind of….

Intestinal contraction.

What is the main function of segmentation?

Mix chyme in place

Is segmentation responsible for moving food forward?

No, it mainly mixes chyme in place

What controls the rhythm of segmentation?

Pacemaker cells in the muscularis externa

What is peristalsis?

gradual movement of contents towards the colon

Where does the peristaltic wave begin in the small intestine?

duodenum

What is the main function of peristalsis?

moves chyme toward the colon.

Approximately how long does it take for chyme to move toward the colon via peristalsis?

2 hours

What is the usual state of the ileocecal valve?

Usually closed

What happens to the ileocecal valve as the cecum fills with residue?

pressure pinches the valve shut

What is the function of the ileocecal valve?

prevents reflux of cecal contents into the ileum.