What role do capillaries play in muscle fibers?

Capillaries play a crucial role in muscle fibers by transporting oxygen. They are tiny blood vessels that form a network around muscle cells, facilitating the exchange of oxygen and nutrients directly with these cells. The close proximity of capillaries to muscle fibers allows for efficient diffusion of oxygen from the blood into the muscle cells, which is essential for aerobic metabolism.

Oxygen is necessary for the production of adenosine triphosphate (ATP) through aerobic pathways, which musculoskeletal cells primarily rely on during extended periods of activity. In addition to oxygen delivery, capillaries also assist in transporting carbon dioxide and other metabolic wastes away from muscle fibers, but their primary role in this context pertains to oxygen transport, making the correct choice accurate.