The small intestine is a narrow long long-winded tube where most of the digestion takes place. It extends 6.7–7.6 meters (22-25 ft) from the stomach to the large intestine. Though the small intestine is longer than the large intestine, it has a smaller diameter. That is why it is called the "small intestine."
The function of the small intestine is the absorption of nutrients from the food into the blood-stream. After the food is churned up in the stomach, a sphincter at the end of the stomach opens to discharge little amounts of food into the small intestine. The first fleshy opening of the small intestine is the duodenum. Peristalsis is the muscular movement in the small intestine through which food is squeezed along the digestive tract. The small intestine has millions of small finger-like projections called villi. Each villus is further divided into tiny microvilli, which are microscopic finger-like protrusions, giving the small intestine a large number of surface area for absorption of nutrients into the blood. The indigestible part of the food goes into the large intestine and is subsequently evacuated from the body. In most animals, the length of the small intestine is about 3 and a half times body length.
The function of the small intestine is the absorption of nutrients from the food into the blood-stream. After the food is churned up in the stomach, a sphincter at the end of the stomach opens to discharge little amounts of food into the small intestine. The first fleshy opening of the small intestine is the duodenum. Peristalsis is the muscular movement in the small intestine through which food is squeezed along the digestive tract. The small intestine has millions of small finger-like projections called villi. Each villus is further divided into tiny microvilli, which are microscopic finger-like protrusions, giving the small intestine a large number of surface area for absorption of nutrients into the blood. The indigestible part of the food goes into the large intestine and is subsequently evacuated from the body. In most animals, the length of the small intestine is about 3 and a half times body length.
