Which method is NOT used for nutrient absorption in the intestines?

Nutrient absorption in the intestines primarily utilizes methods such as passive transport, active transport, and facilitated diffusion. Each of these mechanisms plays a crucial role in how nutrients are taken up from the intestinal lumen into the bloodstream.

Passive transport allows molecules to move across cell membranes without the need for energy, relying on concentration gradients. Active transport, on the other hand, requires energy input to move substances against their concentration gradient, ensuring that essential nutrients are absorbed even when their concentration is lower in the intestinal lumen compared to inside the cells. Facilitated diffusion also allows substances to cross membranes via specific transport proteins, but unlike passive transport, it involves assistance from proteins to facilitate the process.

Convection, however, is not a method used for nutrient absorption in the intestines. This process typically refers to the movement of particles in a fluid due to differences in temperature or density, rather than the selective and energy-dependent processes used to absorb nutrients. Therefore, it does not contribute to the mechanisms through which nutrients are absorbed from the digestive tract into the body.