Question

Describe the role of small intestine in process of digestion

Answer 1

absorption of digested food..

Answer 2

I hope this helps you mate

intestine

The small intestine is the part of the intestines where 90% of the digestion and absorption of food occurs, the other 10% taking place in the stomach and large intestine. The main function of the small intestine is absorption of nutrients and minerals from food.

Digestion involves two distinct parts. The first is mechanical digestion by chewing, grinding, churning and mixing that takes place in the mouth and the stomach. The second part of digestion is the chemical digestion that uses enzymes, bile acids etc. in order to break down food material into a form that can then be absorbed, then assimilated into the tissues of the body. Chemical digestion occurs in the small intestine (and, to a lesser extent, also in some other part of the gastrointestinal tract.

Digestion of proteins

Proteins, peptides and amino acids are acted upon by enzymes such as trypsin and chymotrypsin, secreted by the pancreas. This breaks them down to smaller peptides. Chemical breakdown begins in the stomach and continues until the large intestine.

Digestion of lipids

Enzymes, like lipases secreted from the pancreas, act on fats and lipids in diet. This breaks the triglycerides into free fatty acids and monoglycerides. It is helped by bile salts secreted by the liver and the gall bladder. The lipase is soluble in water but the fatty triglycerides are not. The bile salts hold the triglycerides in the watery environment until the lipase can break them into the smaller parts that can enter the intestinal villi for absorption.

Digestion of carbohydrates

Carbohydrates are broken down to simple sugars and monosaccharides like glucose. Pancreatic amylase breaks down some carbohydrates to oligosaccharides as well. Some carbohydrates and fibers pass undigested to the large intestine where they may, depending on their type, be broken-down by intestinal bacteria.

Absorption in the small intestines

Once broken down the nutrients are absorbed by the inner walls of the small intestine into the blood stream. The nutrients are rendered small enough so that they may pass, or "be transported", across the epithelial cells of the gastrointestinal tract. The nutrients are absorbed by processes of simple/passive diffusion, facilitated diffusion, primary active transport, or secondary active transport.

The small intestine is good for absorption since it has a large inner surface area. This is formed due to the plicae circulares which project many tiny finger-like structures of tissue called villi. The individual epithelial cells also have finger-like projections, which are called known as microvilli.

Please mark as brainliest