Jejunum

Definition

The jejunum is the middle section of the small intestine, situated between the duodenum and the ileum. It plays a crucial role in nutrient absorption during digestion.

5 Must Know Facts For Your Next Test

1. The jejunum is approximately 2.5 meters long in an adult human.
2. It has a highly folded inner surface with villi and microvilli to increase surface area for nutrient absorption.
3. Most of the chemical digestion and nutrient absorption occur in the jejunum.
4. The pH in the jejunum is slightly alkaline, typically around 7 to 8.
5. Blood supply to the jejunum comes from branches of the superior mesenteric artery.

Review Questions

• What function does the jejunum serve in the digestive system?
• How does the structure of the jejunum aid in its function?
• What is the typical pH level found in the jejunum?

Related terms

Duodenum:

The first section of the small intestine where initial digestion occurs.

Ileum:

The last and longest segment of the small intestine responsible for absorbing vitamin B12, bile salts, and remaining nutrients.

Villi:

Small finger-like projections on the inner wall of the small intestine that increase surface area for nutrient absorption.