What does the small intestine do in human body?
The small intestine is a vital part of the human digestive system responsible for digesting food and absorbing essential nutrients. It plays several important functions:
1. Digestion of carbohydrates: The small intestine breaks down carbohydrates into simple sugars like glucose, which can be absorbed into the bloodstream. This process is facilitated by enzymes such as amylase and other enzymes produced by the pancreas.
2. Digestion of proteins: Proteins are broken down into amino acids. The small intestine produces enzymes like protease and peptide, which help in breaking down proteins into smaller components.
3. Digestion of fats: Fats are broken down into smaller fatty acids and glycerol with the help of bile from the liver and enzymes like lipases. These broken-down fats can then be absorbed into the lymphatic system.
4. Absorption of nutrients: The small intestine has a vast surface area, which is covered in tiny finger-like projections called villi. These villi are lined with microvilli that increase the surface area for nutrient absorption. Nutrients from the digested food are absorbed through the villi and transported to the bloodstream.
5. Absorption of water and electrolytes: After the nutrients have been absorbed, the remaining material moves further along the small intestine, where most of the water is absorbed back into the body. Electrolytes such as sodium, potassium, and chloride are also absorbed in this process.
6. Transport of food: The small intestine also has the function of transporting the digested food through its length via peristaltic contractions. These rhythmic muscle movements help move the food along the small intestine and facilitate digestion and absorption.
The small intestine is about 20 feet (6 meters) in length and is the longest part of the digestive system. Its main function is to break down food into smaller nutrient components and absorb these nutrients into the bloodstream. These absorbed nutrients are then distributed to various parts of the body for energy, growth, and other essential bodily functions.