Sistematization, distribution and territoty of the middle cerebral artery on the surface of the brain in Didelphis albiventris (opossum)

Abstract

We study the behavior of the middle cerebral artery, in 30 encephalon of Didelphis albiventris. This vessel along its course branched originating several branches. The ventro-rostral ramus distribute for the olfactory trigonum. Two ventrocaudal rami for the piriform lobe, the medial one distributed itself on the medial surface of the piriform cortex, on the right present in 100.00% and on the left present in 83.30% of the cases; and the lateral one covering the rest of the piriform lobe surface, being present bilaterally in 100.00% of the pieces. Following, the middle cerebral artery emitted the 1º and the 2º dorsolateral hemispheric branches. The 1º dorsolateral hemispheric branch covering the caudal third of the dorsolateral surface of the hemisphere. This branch was present in 96.70.00% and absent in 3.30% of the cases, right side and present in 90.00% and absent in 10.00% of the pieces, left side. The 2º dorsolateral hemispheric branch covered the medium third of the dorsolateral surface of the hemisphere. It was present in both antimeres in 36.70.00% of the pieces. When this two branches were absent its territory was usually complemented by the 1º dorsolateral hemispheric or by the terminal branches. The terminal branch projected dorsally and emitted the rostral and caudal rami to the dorso-lateral surface of the hemisphere. It was present in 100.00% of the cases, both antimeres. The rostrodorsal branch ran rostrally and could reach the dorsal surface of the olfactory bulb. The middle cerebral artery territory involved the piriform lobe surface, part of the olfactory trigonum, lateral olfactory tract and the main part of the dorsolateral surface of the hemisphere.