Question

Describe the main regions and features of the Large Intestine. What are its main functions? What is the population of bacteria in this region of the digestive tract?

Answer 1

Large intestine or colon extends from ileocecal valve up to anus. Parts of large intestine include:

Cecum with appendix, ascending colon, transverse colon, descending colon, sigmoid colon or pelvic colon, rectum and anal canal.

The wall of large intestine is formed by 4 layers such as serous layer, muscular layer, submuscular layer and mucus layer.

The villi present in the mucous membrane of small intestine are absent in the large intestine. Only mucous secreting glands are present in the mucosa of large intestine.

Functions of large intestine include neutralization of acids. Strong acids formed vy bacterial action in large intestine are neutralized by the alkaline nature of large intestinal juice.

Absorptive functionis the another important function. Water, electrolytes, organic substance like glucose, alcohol, drug like anesthetic agents, aedatives and steroids are absorped in the large intestine.

Formation of feces is another function. After the absorption of nutrients, water and other substances, the unwanted substance in the large intestine form feces.

Ecretory function like excretes heavy metals like mercury, lead and arsenic through feces.

Synthetic function. Bacterial flora of large intestine syntheszies folic acid, vitamin B12 and vitamin K.

There are normal flora or bacteria are presented in the large intestine.