The Small Intestine
The Small Intestine
Anatomy and Physiology I
3/10/2014
The majority of the digestive process is done by the small intestine, absorbing almost all of the nutrients you receive from foods into your bloodstream. The small intestine begins at the pyloric sphincter of the stomach and coils around the abdominal cavity, and then opens into the large intestine. “The intestines process about 2.5 gallons of food, liquids and bodily waste every day.” (Inner Body) There are three features that the small intestines have that allow it to be so absorptive. The first feature is the mucosal folds. The inside of the intestine is not flat, it is in circular folds that allow for more surface area and helps regulate the flow of the digested food. The second feature is the villi. These are tiny finger-like projections from the folds that stick out into the open space. They are also covered with cells that help to absorb the nutrients from the passing food. The final feature that aids in absorption is the microvilli. “The cells on the villi are packed full of tiny hairlike structures called microvilli. This helps increase the surface of each individual cell, meaning that each cell can absorb more nutrients.” (Childrens Hospital of Pittsburg) The small intestine has three main functions. The first is that it mixes the chyme with the digestive juices and brings food into contact with mucosa for absorption and then propels the chyme through the intestine. The second function is that it completes the digestion of carbohydrates, lipids, and proteins. It also begins and completes the digestion of nucleic acid. The third function is that it absorbs 90 percent of nutriends that pass through the digestive tract. There are many types of tissues that are found in the small intestine. The main tissues found are epithelial tissue, muscle tissue, and connective tissue. “The epithelial layer is columnar epithelium, which is specialized for absorption and secretion. The muscularis consists
Anatomy and Physiology I
3/10/2014
The majority of the digestive process is done by the small intestine, absorbing almost all of the nutrients you receive from foods into your bloodstream. The small intestine begins at the pyloric sphincter of the stomach and coils around the abdominal cavity, and then opens into the large intestine. “The intestines process about 2.5 gallons of food, liquids and bodily waste every day.” (Inner Body) There are three features that the small intestines have that allow it to be so absorptive. The first feature is the mucosal folds. The inside of the intestine is not flat, it is in circular folds that allow for more surface area and helps regulate the flow of the digested food. The second feature is the villi. These are tiny finger-like projections from the folds that stick out into the open space. They are also covered with cells that help to absorb the nutrients from the passing food. The final feature that aids in absorption is the microvilli. “The cells on the villi are packed full of tiny hairlike structures called microvilli. This helps increase the surface of each individual cell, meaning that each cell can absorb more nutrients.” (Childrens Hospital of Pittsburg) The small intestine has three main functions. The first is that it mixes the chyme with the digestive juices and brings food into contact with mucosa for absorption and then propels the chyme through the intestine. The second function is that it completes the digestion of carbohydrates, lipids, and proteins. It also begins and completes the digestion of nucleic acid. The third function is that it absorbs 90 percent of nutriends that pass through the digestive tract. There are many types of tissues that are found in the small intestine. The main tissues found are epithelial tissue, muscle tissue, and connective tissue. “The epithelial layer is columnar epithelium, which is specialized for absorption and secretion. The muscularis consists
Cited: Biology Lab 102. (n.d.). Retrieved from Rutgers.edu: http://bio.rutgers.edu/~gb102/lab_9/904dm-amphiuma.html Childrens Hospital of Pittsburg. (n.d.). Retrieved from http://www.chp.edu/CHP/organs+intestine Inner Body. (n.d.). Retrieved from http://www.innerbody.com/image_digeov/dige10-new3.html#full-description Zimmermann, K. A. (2012, August 14). Digestive System: Facts, Function & Diseases. Retrieved from Live Science: http://www.livescience.com/22367-digestive-system.html