The Small Intestine

Read this article for an overview of the function, parts and health of the small intestine.

The small intestine is responsible for removing nutrients from food and bringing water and electrolytes in the body. It also moves food through a specific part of the digestive tract, into the large intestine. Read this article to learn about the function, parts and health of the small intestine.

There are three sections of the small intestine. They are classified as the ileum, the jejunum and the duodenum. The intestine moves food along after it is received by the stomach by peristalsis, which occurs when the muscles along the sides of the intestine contract in a rolling motion to push material in a direction. Food, in general, leaves the small intestine after a period of about a half an hour. However, the food may remain in the small intestine for a small while if there is already food in the large intestine.

The function of all three sections of the intestine is to absorb nutrients from food. However, they also contain specific functions. The Ileum is known as the passage from the small intestine to the large interesting. The jejunum is another area of absorption that fills the middle area of the intestine. The duodenum receives secretions from the liver and pancreas using bile ducts. It uses these secretions to extract nutrients from food. The small intestine contains the intestine tube and a method of getting blood to and from the intestine known as the mesentery, This looks like webbing between the tubes of the intestine, and contains lots of blood cells and folds.

The small intestine, when stretched out, is about 6 meters in length. This long amount is cleverly wound so that a large amount of absorptive surface area is placed in a small, contained space. The inner surface of the intestine is made of mucosal folds, or folds covered in mucus, like the stomach. These folds mix food and crimp the intestine to provide large surface area. The surface of these folds are covered with villi, or small hairs that contains cells that will extract nutrients. The surface of villi is covered with epithelial cells, and the surface of these is covered in microvilli. Together, these elements allow the intestine to be capable to ingesting huge amounts of food.

The small intestine does not simply aid in the extraction of nutrients. It also allows the body to take water and electrolytes, which are critical in maintaining regular bodily systems. Sodium pumps establish a gradient across cells in the walls of the intestine to make the absorption of water, nutrients and electrolytes possible. The small intestine contains different systems for extracting water and electrolytes, glucose, peptides and amino acids, and lipids. It then sends these elements through the body with the help of the mesentry and the blood cells it contains.

Problems in the small intestine occur when food is blocked, unable to move, or contains bacteria that cannot be broken down by small intestine cells. Intestinal Dysmotility is a dysfunction that hampers peristalsis, or the contractions that move food forward. When food cannot move forward, cramps and headaches occur in the patient because the digestive process has been stopped unnaturally. Bacterial Overgrowth is a condition that leads to immediate expulsion in the small intestine. If there is an overload of bacteria, the small intestine cannot handle it, and stomach pains and vomiting occur. Cancer can strike the small intestine, although it usually is detected in other parts of the body first. Worms and parasites can occasionally affect small intestine health, although these can most often be removed by careful surgeons or specialized medicines.

Small advances are being made in the area of small intestine health today. Small intestine transplants, while rare, have been performed successfully. Doctors are working on ways to reduce rejection of this organ, which often does not "take" in new bodies because of its unusual size and makeup. Crohn's disease is a disease that can exist inside healthy patients whose bodies mistakenly assume that their small intestine is a transplant, even though they are fine. In these rare cases, the body attempts to rid itself of its own organ, causing cramps, pain and blockage in the process. While this disease is usually not fatal, it gives a strong example of the body's intense awareness of this organ. Certain rare procedures also exist to clean the small intestine, although these are most often used by patients who have parasites or worms inside them.

Scientists are now researching an interesting advance in small intestine research. There appears to be two other types of contractions besides the typical peristalsis that moves food forward toward the lower intestine. The first kind of these obscure contractions is the discrete clustered contraction, or a small, fluttering movement in the upper intestine. These movements may be associated with pain or blockage in the intestine. The second kind is the giant migrating contraction. This contraction is believed to clean bacteria and waste from the intestine, and consists of a very large peristaltic movement through the intestinal sections.

In conclusion, the small intestine is an important part of the digestive tract, bringing nutrients, electrolytes and water inside the body and ushering waste out to the lower intestine. It is a generally healthy organ unless blocked or hampered by bacteria. Advances in study of this organ have yielded several methods of controlling disease and several new types of contractions with which the intestine may cleanse and clear itself. There are few direct ways to keep your small intestine healthy, but, as always, regular diet and exercise are the keys to overall health.

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