How are amino acids absorbed into the bloodstream from the villi in the small intestine?
Do they use active or passive transport through the capillaries?
The inner walls of the small intestine have thousands of finger-like outgrowths called villi (singular villus). The villi increase the surface area for absorption of the digested food. Each villus has a network of thin and small blood vessels close to its surface. The surface of the villi absorbs the digested food materials. The absorbed substances are transported via the blood vessels to different organs of the body where they are used to build complex substances such as the proteins required by our body.
- As the question goes, what is being absorbed depends upon the food that is being digested, for example
•carbohydrates are degraded into simple sugars (e.g., glucose). In the small intestine pancreatic amylase breaks down carbohydrates into oligosaccharides. Brush border enzymes take over from there. The most important brush border enzymes are dextrinase and glucoamylase which further break down oligosaccharides. Other brush border enzymes are maltase, sucrase and lactase.The Small Intestine is the most important part of digestion.
- Similarly if it is proteins then it is broken down in to amino acids by a complex process before it enters the blood stream, the reason for this is because only smaller components are able to enter the villi for absorption.
rest is taken care in the large intestine as undigested food.
Small intestine - Wikipedia, the free encyclopedia