Читать книгу Musculoskeletal Disorders - Sean Gallagher - Страница 74

Skeletal muscle is highly vascularized and can receive up to 80–85% of the heart’s total cardiac output during heavy exercise (Figure 3.9) (Joyner & Casey, 2015). Muscle contraction requires a great deal of energy and, therefore, large amounts of nutrients and oxygen. Moreover, waste products (e.g., lactic acid) produced during the muscle’s energy production reactions need to be eliminated. For this purpose, large blood vessels and nerves enter the epimysium and divide into branches that spread throughout the muscle in the perimysium and endomysium. Numerous capillaries run longitudinally through the endomysium as an “endomyseal capillary bed.” There are frequent transverse anastomoses between these capillaries, resulting in a fine elongated capillary network that surrounds each muscle fiber.