The venous system of the head and neck of the opossum (Didelphis virginiana)

Abstract

The venous system of the head and neck of the opossum, Didelphis virginiana, was studied by injecting the veins with a tinctorial mass. Gross dissection specimens injected with a colored gelatin solution and corrosion specimens prepared by Batson's technique (Batson, ' 5 5 ) were utilized to describe the venous pattern in greater detail than is presently available in the literature. The venous drainage of the superficial structures of the head is principally by way of the V. jugularis externa and its tributaries. Although small emissary veins connect the Sinus cavernosus with the Plexus pterygoideus and the V. maxillaris, the dural venous sinuses drain primarily into the Plexus vertebralis internus and into the V. maxillaris by way of the V. emissaria foraminis retroarticularis. The small V. jugularis interna receives minor connections from the PZexus pterygoideus, the Sinus cavernosus and the Sinus petrosus ventralis as well as anastomotic tributaries from the Plexus vertebralis and the plexus of veins around the hyoid bone. However, the V. jugularis interna serves mainly as a pathway for venous drainage from the deeper structures of the neck and only minimally for draining the brain.

Evidence of early evolution of Australidelphia (Metatheria, Mammalia) in South America: phylogenetic relationships of the metatherians from the Late Palaeocene of Itaboraí (Brazil) based on teeth and petrosal bones

“…The transverse sinus runs in the outer edge of the tentorium cerebelli and divides into two branches. The anteroventral branch exits from the skull via the postglenoid canal (prootic sinus and sphenoparietal emissary vein), and the posterodorsal branch via the foramen magnum (Dom, Fisher & Martin, 1970).…”

Cranial endocasts from a growth series of Monodelphis domestica (Didelphidae, Marsupialia): A study of individual and ontogenetic variation

“…10) and D. virginiana (Loo, 1930;Dom et al, 1970;Nieuwenhuys et al, 1998). The large, paired transverse sinus, confluens sinuum, and associated meninges on the dorsoventral surface of the endocasts are responsible for covering the midbrain (Dom et al, 1970). The transverse sinus casts are visible on all of the endocasts of M. domestica examined here except for two of the Day 27 individuals (TMM M-8261 and TMM M-8265; Fig.…”

“…Conversely, the inferior and superior colliculi of the midbrain are visible on the dorsal surfaces of corresponding brains of M. domestica (Fig. 10) and D. virginiana (Loo, 1930;Dom et al, 1970;Nieuwenhuys et al, 1998). The large, paired transverse sinus, confluens sinuum, and associated meninges on the dorsoventral surface of the endocasts are responsible for covering the midbrain (Dom et al, 1970).…”

“…The midbrain is not exposed on the dorsal surface of any of the endocasts of Monodelphis domestica or Didelphis virginiana. Dissections indicate that large blood sinuses, particularly the paired transverse sinus and confluens sinuum, are responsible for obscuring the midbrain from dorsal view on endocasts (Dom et al, 1970).…”

“…We compared these endocasts with the gross anatomy of brains of M. domestica that were extracted by dissection from individuals of comparable age. We also compared the endocasts of M. domestica with an endocast from an adult Didelphis virginiana, the Virginia opossum, because the gross anatomy of the brain and associated soft tissue of D. virginiana is well documented (Voris, 1928;Loo, 1930;Voris and Hoerr, 1932;Larsell, 1936;Krabbe, 1942;Dom et al, 1970;Nieuwenhuys et al, 1998). The morphology of endocasts of adult M. domestica was compared elsewhere with an endocast of Pucadelphys andinus, an extinct metatherian from Bolivia (Macrini et al, 2007a).…”