Gross and scanning electron microscopy of the carotid rete--cavernous sinus complex of the sheep (Ovis aries).

Intravascularly plastic injected specimens of the carotid rete of the sheep were investigated. In addition, glutaraldehyde-fixed, freeze-fractured and sputter-coated retia were examined by SEM. The carotid rete is supplied by one caudal and 2-4 rostral rete branches of the maxillary artery, with a few variations in the origin of the rostral rete branches. The tunica adventitia of muscular arteries was continuous with that of the cavernous sinus. The endothelial cells of the cavernous sinus were differently oriented than those of the arterial rete branches. In addition, craters were found in the endothelial cells of the arteries but not in those of the cavernous sinus.