[Venous networks and plexuses in the masticatory muscles]

Studied were the structure and localization of the venous plexuses in the chewing muscles of a total of twenty newborn and growing lambs and sheep (aged up to 8 years) of both sexes through preparation, corrosion, and measuring. It was found that the venous plexuses were localized within the muscles and had definite boundaries. They were shown to be connected with the muscles and the periosteum of the neighbouring bones, and lay in the way of the emissary and bone veins and the veins that came from the muscles. The venous plexuses formed loops of a varying size and form, and the veins had two layer valvulae. In newborn lambs the plexuses were at birth well structured and localized. The venous vessels were found to be in close contact with the branching of the regional arteries. Numerical data are given concerning the size of the plexuses observed. It was assumed that these structures, beside their collecting the blood from the muscles, the rostral portion of the maxillary sinus, the alveolae of the last two molars of the maxilla, the brain and the venous sinuses in dura mater, are also of hemodynamic importance with regard to the correct distribution of the blood and its downward course (from the head to the neck).