Digestive Processes of the Large Intestine

1. Bacterial Flora
1. digest remaining carbohydrates
2. responsible for producing gas (flatus)
3. synthesize complex B vitamins and vitamin K
2. Digestion and Absorption
1. reclaim most of the water
2. reclaim some of the electrolytes (Na+ and Cl-)
3. Motility of the Large Intestine
1. haustral contractions - slow acting segmental motion; moves chyme from one segment to next
2. mass movements - peristaltic waves that move food to the rectum during/after eating
• diverticula - herniation of the mucosa through the wall of the colon sigmoidd colon)
4. Defecation
1. defecation reflex - when feces (stool) enters rectum, spinal cord reflex is triggered
• internal sphincter (involuntary)
• external sphincter (voluntary)
2. Valsalva's maneuver - contraction of diaphragm and abdominal muscles to increase pressure for defecation
3. diarrhea - too much water in the stool
4. constipation - insufficient water or fiber

Category: Physiology Notes