Mucous membrane of intestine

Question

Subsequent to digestion the later step is absorption completed by cells of the mucous membrane of intestine. For this task a big absorption surface is a benefit. How is it probable in the small interior space of the body of a pluricellular organism to exist a big intestinal surface?

Answer 1

Evolution tried to resolve this problem in two manners. The simplest is the tubular and long shape of the bowels (around eight meters in extension), making possible which numerous small intestine loops fold closely. Much efficient solutions are intestinal villi and the microvilli of the mucosal membrane cells.The intestinal wall are not much smooth. The mucous membrane, altogether with its submucosa, projects within the gut lumen such as glove fingers making invaginations and villi which multiply the obtainable surface for absorption. Additionally the epithelial cells whihc cover such villi encompass themselves numerous hair like projections termed as microvilli on the exterior face (lumen face) of their plasma membrane. The absorptive region of the intestines is therefore raised hundreds of times with such solutions. In the jejunum and ileum there are folds which have the function of raising the absorption surface too.