KINS 1224 Chapter Notes - Chapter 25: Nerve Plexus, Duodenum, Defecation
Document Summary
The large intestine harbors about 800 species of bacteria collectively called the bacterial flora. We have a mutually beneficially relationship with many of these. The bacteria can provide us with nutrients from food we are not equipped to extract on our own like cellulose and pectin which are digested for sugars. Some bacteria also synthesize b vitamins and vitamin k which are absorbed by the colon. Vitamin k is important bc the diet alone usually does not provide enough to ensure adequate blood clotting. The large intestine contains about 7-10l of gas expelling 500ml a day as flatus and reabsorbing the rest. Flatus is composed of n2, co2, h2, ch4(methane), hydrogen sulfide(h2s) and 2 amines indole and skatole. Indole, skatole, and h2s produce the odor of flatus and feces whereas the others are odorless. The large intestine takes 12-24 hours to reduce the residue of ta meal to feces. Feces consist of about 75% water and 25% solids.
