Mucosal villi are finger-like projections that increase the surface area of the lining of the small intestine, aiding in nutrient absorption. They are modifications of the mucosal surface.
Understanding Mucosal Villi
Villi are crucial for efficient absorption in the small intestine. Let's break down their structure and function:
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Structure: According to the provided reference [1,2], villi are:
- Mucosal Surface Modifications: They are extensions of the lining epithelium.
- Finger-like Projections: These projections increase the surface area for absorption.
- Lamina Propria Core: Each villus contains lamina propria (connective tissue) covered by epithelium.
- Intestinal Glands (Crypts of Lieberkuhn): Each villus extends into the lamina propria as an intestinal gland or crypt of Lieberkuhn. These crypts contain important cells such as:
- Stem cells: Responsible for regenerating the intestinal lining.
- Paneth cells: Secrete antimicrobial substances.
- Enteroendocrine cells: Produce hormones that regulate digestion.
Role in Nutrient Absorption
The increased surface area provided by the villi is critical for absorbing nutrients from digested food. More surface area means more opportunities for nutrients to be absorbed into the bloodstream.
Summary Table
| Feature | Description |
|---|---|
| Definition | Finger-like projections extending from the lining of the small intestine. |
| Function | Increase surface area for nutrient absorption. |
| Composition | Lamina propria covered by epithelium. |
| Associated Structures | Intestinal glands (crypts of Lieberkuhn) containing stem cells, Paneth cells, and enteroendocrine cells. |
