What are villi?

Villi are small, finger-like projections found in the lining of the small intestine. Their primary function is to increase the surface area available for the absorption of nutrients from digested food. The presence of these villi significantly enhances the intestine's ability to absorb essential vitamins, minerals, carbohydrates, proteins, and fats effectively.

Each villus is covered with even smaller hair-like structures called microvilli, which further amplify the absorptive capacity, creating a large surface area critical for the digestive process. This structural adaptation is vital for the efficient uptake of nutrients, allowing the body to maximize its use of the nutrients present in food.

The other options do not accurately describe villi, as digestive enzymes are produced in the pancreas, muscle tissues related to peristalsis are involved in the movement of food through the digestive tract, and cell membranes in the stomach lining have a different role, primarily focused on secretion rather than absorption.