Blood flow in the capillary network of muscle tissue

Abstract

The capillary network in skeletal muscle is a system of vessels oriented more or less parallel to the muscle fibers with cross links [1]. The blood enters the capillaries from precapillary arterioles oriented across the fibers and is drained into the postcapillary venules which also run in the transverse direction. Along the path of the muscle fibers the unit vascular complexes, comprising a precapillary arteriole, post-capillary venule (first-order vessels) and the connecting capillaries, are repeated. Successive complexes have common vessels of the second order: a blood-supplying arteriole and a blood-draining venule. Since the vessels are in an ordered arrangement and the density of the capillaries is fairly high (10²–10³ mm⁻²), to describe the motion of the blood in them it is natural to employ the theory of flow through porous media. This paper is concerned with the formulation and a general algorithm for the solution of the problem of blood flow in a system of capillaries and microvessels (arterial and venous) of the first two orders. The flow in the individual unit vascular complex is analyzed in detail.