Which system is primarily involved in the absorption of nutrients?

The digestive system is primarily responsible for the absorption of nutrients. This system includes various organs such as the mouth, esophagus, stomach, small intestine, and large intestine, each playing a specific role in breaking down food and facilitating nutrient uptake.

In the small intestine, for example, the walls are lined with tiny projections called villi and microvilli that increase the surface area for absorption, allowing nutrients from digested food to enter the bloodstream effectively. The digestive process also involves the secretion of enzymes and digestive acids that break down the food into smaller components, which can then be absorbed into the body.

Other systems, such as the circulatory system, do play a role in transporting nutrients once they have been absorbed, but they are not directly involved in the absorption process itself. Therefore, the digestive system is the key player in nutrient absorption, making it the correct answer.