We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Conditions

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What is the Jejunum?

Mary McMahon
By
Updated: Mar 03, 2024
Views: 35,092
Share

The jejunum is the second part of the small intestine, connecting the duodenum with the ilium. It is also the longest section of the small intestine, commonly comprising almost half its length. This area of the intestines is supplied with blood by the superior mesenteric artery, and is held in place by the mesentery, part of the peritoneum which lines the stomach cavity. Rather than being firmly positioned, the jejunum is actually suspended, which allows it to move within the stomach cavity as digestive processes occur.

This area of the small intestine has a very large surface area, created in part by folds of tissue. Projections known as villi also increase the surface area of the jejunum, with each projection sticking up like a small finger. The villi are responsible for absorbing nutrients, with the jejunum being the area in which absorption begins in the small intestine. Reuptake of bile also occurs in the jejunum.

The jejunum also secretes digestive enzymes which break down foods into units which can be absorbed by the intestine. This enzyme secretion, which actually starts in the stomach, is a key part of digestion. Without digestive enzymes, the intestine cannot actually access many of the nutrients in food, and thus will not be able to utilize food for nutrition. Impairments in nutrient production caused by congenital conditions or disease can be a source of malnutrition for a patient.

It is sometimes necessary to remove all or part of the jejunum. One cause for removal is the growth of a cancer which compromises the small intestine, and another is traumatic injury so severe that it cannot be repaired. If the blood supply to this area of the intestine is cut off, this can also necessitate removal, as parts of the jejunum may die if the blood supply is cut off for too long. Removal is performed by a surgical team with the patient under general anesthesia.

When parts of the jejunum are removed, patients must take special precautions. They are at risk of malnutrition both because they are missing an area of the intestine where absorption occurs, and because they may not be producing all of the enzymes they need. Some dietary modifications may be necessary to ensure that the patient gets proper nutrition, and the patient will be given specific advice by a doctor to learn what to eat and when, and to find out about supplementation options which will keep the patient's body nourished.

Share
The Health Board is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Mary McMahon
By Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a The Health Board researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Discussion Comments
By croydon — On Aug 22, 2011

@irontoenail - The way our teacher tried to get us interested in the jejunum and ileum was to tell us about how, if you got hit with a lot of force in that area, you would end up vomiting. It's a reflex known as emesis.

Of course, then we all went around threatening each other with emesis (jokingly of course!) for the next few days, but at least we remembered the word!

The other thing she told us was that sausage casings are made from parts of the intestine from farm animals. Not always, because sometimes they use artificial ones now, but more often than not.

I think quite a few people in the class looked at sausages with different eyes after that!

By irontoenail — On Aug 21, 2011

The jejunum is that long squishy part of the intestine that looks like it is kind of stuffed underneath the more muscular looking ileum.

We studied it in one of my biology classes. I guess I quite liked the name, which means "hungry" in old English.

Apparently since they used to find this part of the stomach empty when people died, they called it that. My teacher always tries to give us a little bit of information like that to make the word easier to remember.

The jejunum is usually about 2.5m long, which is kind of crazy, because that's quite a lot longer than your whole body.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a...

Learn more
Share
https://www.thehealthboard.com/what-is-the-jejunum.htm
Copy this link
The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.

The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.