Jejunum

Jejunum is the middle section of the small intestine found in humans and most higher vertebrates. It is located between the duodenum and the ileum. The jejunum is responsible for the majority of nutrient absorption in the digestive process.

Anatomy

The jejunum is approximately 2.5 meters long in adults and is larger in diameter than the ileum. It is typically located in the upper left part of the abdomen. The lining of the jejunum is specialized for the absorption of carbohydrates and proteins, with its lining being covered in projections called villi and microvilli to increase its surface area for absorption.

Function

The primary function of the jejunum is the absorption of important nutrients in the digestive process. These nutrients include simple sugars derived from carbohydrates, amino acids derived from proteins, and fatty acids and glycerol derived from fats. The absorbed substances are then passed into the blood and lymph vessels in the wall of the intestine.

Clinical significance

Diseases of the jejunum can have serious health impacts. These include Crohn's disease, which can affect any part of the gastrointestinal tract but most often affects the end of the small intestine, and celiac disease, which is a reaction to eating gluten that damages the lining of the small intestine.

See also

• Digestive system
• Gastroenterology

Jejunum

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  Diagram of the small intestine
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  Anatomy of the jejunum
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  Microvilli of the jejunum
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  Electron micrograph of a nude mouse jejunum
• Histological section of dog jejunum at 100x magnification
  Histological section of dog jejunum at 100x magnification