Small Intestine
The small intestine is a 20-foot long convoluted tube located in the abdominal cavity. It is composed of smooth muscle layers and a mucous membrane divided into three sections: duodenum, jejunum, and ileum.
Food from the stomach enters the duodenum through the pyloric sphincter. It then enters the jejunum and exits into the large intestine through the ileum. Bile from the gallbladder and pancreatic juice are secreted into this area and aid in digestion of fats, large proteins, and carbohydrates. Most of the absorption occurs in the small intestine.
The small intestines have very fine, finger-like projections called villi, which absorb nutritive substances. These villi increase the surface area of the intestine, thus allowing a greater potential absorption rate. The nutritive substances, including vitamins and minerals, pass through the walls of the villi. There are many capillaries within each villus for nutrient transport, first to the liver and then on to the rest of the body.
References
Gray, H. 1977. Gray's Anatomy. Crown Publishers, Inc. New York. 1257 pp.
Lockhart, R.D., G.F. Hamilton, et.al. 1974. Anatomy of The Human Body. Faber and Faber Limited. London. 697 pp.
Van Amerongen, C. The Way Things Work; Book Of The Body. New York: Simon and Schuster, 1979.
| Signup Free Applied Health Journal |
||||
|
FREE Sample Issue Your email address is all we need to start you on a better path to health. We respect your privacy.
|
