Jejunum: Part of the Small Intestine

Understanding the Function of the Jejunum

jejunum, small intestine,
The Small Intestine. Image: (c) ADAM

Definition: The jejunum is the middle portion of the small intestine, connecting the duodenum and the ileum.

The Function of the Jejunum

The jejunum, along with the other areas of the small intestine, is responsible for absorbing nutrients from digested food into the bloodstream. The jejunum is able to absorb these nutrients because it is lined with finger-like projections that are called villi.  The villi are able to absorb nutrients in the form of minerals, electrolytes, and carbohydrates, proteins, and fats that were consumed in the form of food and absorb them into the bloodstream where they are able to be utilized by the entire body.

The jejunum, as well as the rest of the small intestine, make it possible to change food into energy, powering the body for daily activities. Without the small intestine, food would pass through the body but we would gain no nutrients, and would quickly starve.  

About the Jejunum

The jejunum is approximately eight feet long in the average adult.  The jejunum begins at the suspensory muscle of the duodenum.  This muscle indicates the end of the first segment of the small intestine and the beginning of the jejunum.  There is no clear indication where the duodenum ends and the final segment of the small intestine, the ileum begins. 

Pronunciation: juh-jew-num

Also Known As: small intestine

Common Misspellings: jayjunum, jejoonum, jejunm, jejunem,

Examples: During some types of weight loss surgery parts of the jejunum are bypassed to decrease the number of calories that can be digested.  This can lead to malnutrition in some patients as the digestion of electrolytes and minerals are also decreased.


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