Ontogenesis of the vascular bed in the human skeletal muscles.

The ontogenetic development of the vascular bed was studied in the muscles of human fetuses after India ink and gelatine injections. By the 12th week of intrauterine life the architectural arrangement of the largest (primary) intra-muscular vessels is qualitatively comparable with that of the adult muscles. The smaller (secondary) vessels, as well as the microcirculatory bed, have very immature features in all fetal muscles studied. This part of the vascular bed develops gradually during further time from a primitive intramuscular capillary network. The basic architectural arrangement of the microcirculatory bed in adult muscles, and the development of the structure of the hilar vessels of the gastrocnemius muscle were described in the muscles of fetuses, newborns, and adults.