THE PTERYGOID VENOUS PLEXUSES

The pterygoid venous plexuses are closely adjacent to the lateral pter ygoid m. and occupy a considerable part of the infratemporal fossa (IT F). We have conducted a study after injection of colored latex in 10 u nembalmed subjects in order to define the arrangement of the venous ne twork and to assess the frequency of the different types of plexuses f ound. In all the subjects symmetry was noted between the right and lef t plexuses, with predominance of the venous layer in the upper part of the ITF. The pattern most often encountered was plexiform and complex . The development of these plexuses follows that of the masticatory mu scles, whose contraction promotes drainage and represents an alternati ve venous pathway for drainage of the cranial cavity.