Morphology of the temporal canal and postglenoid foramen with reference to the size of the jugular foramen in man and selected species of animals

Jarosław Wysocki


The jugular foramen and postglenoid foramen are the main venous foramina of
the skull of placental mammals. Their mutual relations are closely related to the
development of the internal and external jugular vein, depending on the given
kind. On the basis of measuring studies, it was decided to investigate the relations
of the size of these foramina and to quantitatively determine which of them prevails.
The studies were performed with macerated human and animal skulls. Altogether
100 skulls of human adults of both sexes, 100 of macaccas, 67 of bisons,
25 of mongrel dogs, 37 of foxes and 25 of rats were examined. The jugular
foramen was the outlet of the sigmoid sinus or its equivalents and the postglenoid
foramen — the petrosquamous or temporal canal. The jugular foramen was always
singular and characterised by a small variability in the morphology, consisting
only in the occurrence of the internal division or its lack. The postglenoid
foramen, on the other hand, in the majority of the studied kinds was variable and
numerous. The number of foramina ranged from 1 in man to 7–10 in bisons. In
the course of measurements, it was found that the area of the postglenoid foramen
in relation to the area of the jugular foramen is 0.87% in man, 24% in
macaccas, 30.7% in dogs, 34.4% in foxes, 53.9% in rats and 248.5% in bisons.
The results obtained indicate that in bisons the system of venous sinuses, connected
with the postglenoid foramina, has a decisive significance for the drainage of
the cranial cavity. In contrast, the postglenoid foramen in man has a marginal
significance. The remaining kinds, whose skulls have been investigated, occupy
on that score an intermediate position.


postglenoid foramen; jogular foramen; skull; human; animals

By  "Via Medica sp. z o.o." sp.k., Świętokrzyska 73, 80–180 Gdańsk, Poland

tel.:+48 58 320 94 94, faks:+48 58 320 94 60, e-mail: