What pathway does oxygen leave capillaries to supply body tissue?

Oxygen leaves capillaries through a process called diffusion. This occurs when oxygen, present in higher concentrations in the capillaries, moves into the surrounding tissues where the concentration is lower. The thin walls of the capillaries facilitate this exchange, allowing oxygen to enter cells and support cellular respiration. Concurrently, carbon dioxide produced by cells diffuses back into the capillaries to be transported away for exhalation.