General Principles of Physiology 2025 – 400 Free Practice Questions to Pass the Exam

Facilitated diffusion plays a crucial role in the absorption of glucose from the lumen of the intestine into the epithelial cells. This process involves specific transport proteins, such as glucose transporters, which facilitate the movement of glucose down its concentration gradient.

In the intestinal lumen, glucose is present at a higher concentration after carbohydrate digestion, compared to the concentration inside the epithelial cells. Facilitated diffusion allows for the efficient uptake of glucose into the cells without the expenditure of energy, as it utilizes the inherent kinetic energy of molecules moving from an area of higher concentration to one of lower concentration.

This mechanism is essential for ensuring that glucose, a vital energy source for cells, is adequately absorbed into the body efficiently. Other options presented do not pertain directly to the function of facilitated diffusion in this context.