What are tiny, finger-like projections found on the surface of epithelial cells in the small intestine called?

The tiny, finger-like projections found on the surface of epithelial cells in the small intestine are known as microvilli. These structures significantly increase the surface area of the intestinal lining, enhancing the absorption of nutrients. The presence of microvilli creates a brush border that is particularly effective in maximizing the efficiency of nutrient uptake, as it allows for more extensive contact between the epithelial cells and the digested food particles.

The increased surface area is crucial in the small intestine, where a large amount of nutrient absorption occurs. Microvilli contain numerous enzymes and transport proteins that facilitate the breakdown and absorption of carbohydrates, proteins, and lipids. This specialized adaptation is a key factor in the digestive system's overall efficiency, making microvilli essential for sustaining the body's nutritional needs.

While cilia, villi, and plicae are also important structures located in the digestive system or other tissues, they have different functions and characteristics. Cilia, for instance, are involved in movement, such as the sweeping action of mucus in the respiratory system. Villi are larger projections that help to increase surface area as well, but they are composed of a different type of tissue layer and are not the same as the microscopic structures of microvilli. Plicae