Microvilli

Definition

Microvilli are tiny, finger-like projections that extend from the surface of epithelial cells, significantly increasing the surface area for absorption and secretion. These structures are particularly abundant in the small intestine, where they play a crucial role in nutrient absorption by maximizing contact with the intestinal contents. Microvilli are essential for efficient digestion and nutrient uptake, facilitating the body's ability to absorb vitamins, minerals, and other essential nutrients.

5 Must Know Facts For Your Next Test

1. Microvilli increase the absorptive surface area of the intestinal lining, making them vital for effective nutrient uptake.
2. Each microvillus is supported by a core of actin filaments, which help maintain its structure and stability.
3. The surface of microvilli contains enzymes and transport proteins that aid in the digestion and absorption of nutrients.
4. In healthy individuals, microvilli can significantly enhance the efficiency of nutrient absorption by providing more pathways for transport.
5. Dysfunction or damage to microvilli can lead to malabsorption syndromes, affecting overall health and nutrition.

Review Questions

• How do microvilli contribute to nutrient absorption in the digestive system?
  • Microvilli play a crucial role in nutrient absorption by significantly increasing the surface area of intestinal epithelial cells. This enlarged surface allows for more effective contact with digested food particles, enhancing the body's ability to absorb vitamins, minerals, and other nutrients. The presence of enzymes on the microvilli further aids in breaking down nutrients for easier uptake into the bloodstream.
• Discuss the relationship between microvilli and villi in the small intestine's structure and function.
  • Microvilli and villi work together to maximize the absorptive capacity of the small intestine. Villi are larger projections that extend from the intestinal wall, while microvilli are found on the surface of each villus. This combination creates an extensive brush border that dramatically increases the surface area available for absorption, enabling efficient nutrient uptake during digestion.
• Evaluate the implications of damaged or dysfunctional microvilli on overall digestive health and nutrition.
  • Damaged or dysfunctional microvilli can severely impact digestive health by leading to malabsorption syndromes. This condition can result in insufficient absorption of essential nutrients, causing deficiencies that affect overall health. Additionally, such dysfunction may lead to gastrointestinal symptoms like diarrhea or bloating, further complicating nutritional intake and overall well-being.

Related terms

Villi:

Villi are larger, finger-like projections found on the inner surface of the small intestine that increase its surface area for absorption. Each villus is covered with microvilli.

Intestinal epithelium: The intestinal epithelium is a layer of cells lining the gastrointestinal tract, responsible for nutrient absorption and barrier functions against pathogens.

Brush border: The brush border refers to the microvilli-covered surface of intestinal epithelial cells that resembles a brush under a microscope, crucial for enhancing nutrient absorption.