Systematization, Description, and Territory of the Middle Cerebral, Rostral, and Cerebroethmoidal Arteries on the Surface of the Brain of the Ostrich (Struthio camelus).

Thirty ostrich specimens were injected with red-dyed latex via the internal carotid arteries (Aa.) The middle cerebral and cerebroethmoidal arteries and their branches were systematized. The middle cerebral artery (a.) was always a single large vessel. On the right side, it had two, three, or one developed medial hemispheric branches in 46.6%, 26.7%, and 26.7% of cases, respectively. On the left side, one (36.7%), two (33.3%), and three (30%) developed medial hemispheric branches were observed. The middle cerebral artery had eight (40%), nine (20%), seven (16.7%), eleven (6.7%) ten (6.7%), twelve (3.3%), six (3.3%), and five (3.3%) developed lateral hemispheric branches on the right side and seven (46.7%), nine (13.3%), eight (13.3%), six (10%), five (10%), and ten (6.7%) on the left. Two (33.3%), four (20%), three (20%), one (16.7%), and five (10%) direct perforating branches of the middle cerebral artery were present on the right, and three (33.3%), two (30%), one (13.4%), six (10%), four (10%), and five (3.3%) were present on the left. The cerebroethmoidal artery, always present as a natural continuation of the rostral terminal branch of the brain's carotid artery and originating from the middle cerebral artery, was a large vessel that projected rostromedially, giving off the rostral cerebral artery shortly after its formation and continuing as the ethmoidal artery. The rostral cerebral artery was a single (90%) and double (10%) vessel on the right and a single (96.7%) and double vessel (3.3%) on the left. The ethmoidal artery was always a medium to large single vessel and was the natural continuation of the cerebroethmoidal artery, immediately after giving off the rostral cerebral artery. Anat Rec, 302:1187-1194, 2019. © 2018 Wiley Periodicals, Inc.