Microvilli and villi are both finger-like projections found in the digestive system, particularly in the small intestine, but they differ in size and function.
Villi are larger, finger-like projections that extend into the lumen of the small intestine. They are covered with a layer of epithelial cells. Their primary function is to increase the surface area of the small intestine, allowing for more efficient absorption of nutrients from digested food.
Microvilli are much smaller, hair-like projections that cover the surface of each villus. They are extensions of the plasma membrane of the epithelial cells. Their function is to further increase the surface area of the small intestine, maximizing nutrient absorption.
Here's a table summarizing the key differences:
| Feature | Villi | Microvilli |
|---|---|---|
| Size | Larger, finger-like projections | Smaller, hair-like projections |
| Location | Extend into the lumen of the small intestine | Cover the surface of each villus |
| Function | Increase surface area for nutrient absorption | Further increase surface area for nutrient absorption |
In essence, villi are the larger, more visible projections, while microvilli are tiny extensions that cover the villi, creating a brush-like border. This intricate structure ensures that the small intestine can absorb the maximum amount of nutrients from digested food.
