What is the intestine? Description of the intestine
THE INTESTINE is the portion of the digestive tract that is located between the stomach and rectum.
Parts of the intestine
In the human being, the intestine is divided into two parts:
- Small intestine: It measures approximately 6 m in length and about 3 cm thick. Situated in the center of the abdominal cavity. Its main function is to digest food and absorb nutrients. To digest food, it secretes a series of enzymes along with a mucus that is intended to serve as a lubricant.
So that food can move the muscular walls of small and large intestines, the movements of contraction are performed, a movement called peristalsis. The intestinal wall is covered with hairiness where the absorption of nutrients into the blood takes place.
The small intestine consists of the following parts:
- Duodenum: The portion that connects the stomach and the jejunum. Its main function is the breakdown of food, after these have passed from the stomach through the pylorus by the pyloric sphincter which regulates the entry of the alimentary bolus (chyme) into the intestine.
- Jejunum: The middle portion of the small intestine, with 1 or 2 meters in length. This part begins the process of absorption of food. Is attached to the abdomen by a membrane called the mesentery.
- Ileum: Two to four meters in length, is the final part of the small intestine. Its main function is the absorption of food.
- Large intestine: It is approximately 1.5 m but is thicker than the small intestine, reaching about 10 cm. Its main function is to transform food from the small intestine (chyme) in feces by the action of intestinal flora, to store stool until his expulsion to the outside, to regulate body fluid balance and to absorb certain vitamins and minerals. It consists of three parts:
- Cecum: This is the part that connects the small intestine with the bulk through the ileocecal valve. It is between 5 and 7 cm in length. You end sac, hence it is called blind. At the bottom of the vermiform appendix hangs, about 9 cm in length, whose function is not entirely known but is assumed to have the purpose of producing antibodies.
- Colon: The portion of the large intestine that runs from the cecum to the rectum. It consists of:
- Ascending Colon: The part of the colon to the right to the crease liver or colon area is doubled. So called because it is up to the liver.
- Transverse colon: colon is the part of transversally located in the lower abdomen.
- Descending colon is the part to the left of the body between the transverse and sigmoid
- Sigmoid Colon: the part between the descending colon and rectum. S-shaped, hence the name of the sigmoid and has powerful muscles responsible for advancing the stool toward the rectum.
- Rectum: Portion of the large intestine between the colon and anus. With an area of about 20 cm is the party responsible for the storage of feces, which are expelled to the outside through an opening called the anus.
- Anus: is the external opening of the rectum. The anus has a so-called sphincter muscles that they control the output of feces to the outside. The inside is smooth muscle and its action is involuntary and the outer is striated muscle and muscle is voluntary action.
Functions of the intestine
The act of expelling feces outside this exercise occurs when the sphincter pressure is called defecate or, more commonly known as "shit". " made " or "crap".
The opening of the anal sphincter occurs in a conscious and voluntary. In the emptying process intervene the peristalsis in the rectum and colon, as well as the strong contractions of the abdominal muscles and anal sphincter relaxation.