The jejunum is the middle portion of the small intestine, connecting the first portion of the small intestine (duodenum) with the last section (ileum).
The cells lining the jejunum are responsible for absorbing the nutrients that are released from food during the process of digestion.To help facilitate this process, the surface area of the small intestine is increased many-fold due to the presence of villi, or finger-like projections, that change the appearance of the inside of the intestine from a flat to a very deep-pile carpet.
The cells lining these villi absorb dietary nutrients including sugars, amino acids, and fatty acids. These nutrients are absorbed from the intestinal cavity (or lumen), travel across the jejunal cells, and then are passed into the bloodstream, where they can be carried to distant parts of the body and used to support cell metabolism and growth.Thesmall intestineis between 22 and 25 feet long, and is folded many times; the jejunum is approximately eight feet long in the average adult.
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Function
The jejunum and the rest of the small intestine make it possible to change the food that we eat into energy that we need for daily activities. Without the small intestine, food would pass through the digestive tract without the absorption of nutrients, and we would quickly starve.
Anatomy
The transition between the duodenum and jejunum occurs at the suspensory ligament, or Ligament of Treitz, that is typically present in the left upper quadrant of the abdomen and just behind the stomach. There is no clear indication where the duodenum ends and the final segment of the small intestine, or ileum, begins.
Intestines: Anatomy and Function
Disorders
As part of the small intestine, the jejunum is subject to a number of disorders. A few of these include:
Crohn’s diseaseis a form of inflammatory bowel disease that can affect any portion of the gastrointestinal tract. Rarely, Crohn’s disease can manifest as jejunoileitis, or inflammation of the jejunum and ileum. Patients with Crohn’s disease s typically present with symptoms including cramps, pain, and diarrhea.
The Role of the Jejunum in Gastric Bypass Surgery
6 Sources
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Collins JT, Badireddy M.Anatomy, abdomen and pelvis, small intestine. Treasure Island, FL. StatPearls Publishing.
Radiopaedia.Ligament of Treitz.
MedlinePlus.Small intestine disorders.
John Hopkins Medicine.Crohn’s disease introduction.
MedlinePlus.Roux-en-y stomach surgery for weight loss.
Medline Plus.Small intestine disorders. US National Library of Medicine. Web.Pubmed Health.Jejunum. US National Library of Medicine. Web.
Medline Plus.Small intestine disorders. US National Library of Medicine. Web.
Pubmed Health.Jejunum. US National Library of Medicine. Web.
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