Systematization, description and territory of the caudal cerebral artery of the brain in broad-snouted Caiman (Caiman latirostris)

Abstract

Pesq. Vet. Bras. 31(9):817-822, setembro 2011 RESUMO.-[Sistematização, descrição e território da arté-ria cerebral caudal no cérebro do jacaré do papo-amarelo (Caiman latirostris).] Foram utilizadas trinta cabeças com o segmento de pescoço de Caiman latirostris. Os animais eram provenientes do Criatório Mister Caiman sob a autorização do Instituto Brasileiro de Meio Ambiente e dos Recursos Naturais Renováveis (Ibama). Os animais foram sacrificados de acordo com as normas de rotina de abate do frigorífico e as cabeças foram seccionadas na altura da terceira vértebra cervical. O sistema arterial foi lavado com solução salina 0.9% resfriada, com drenagem pelas veias jugulares. Em seguida, o sistema foi preenchido com injeção de látex, corado em vermelho As peças foram então fixadas em formaldeído a 20.0% por sete dias. O cérebro foi removido, com um segmento de medula espinhal, a dura-máter retirada e as artérias dissecadas. Na altura da hipófise, a artéria carótida interna emitiu um ramo rostral e, um curto ramo caudal, continuando-se naturalmente, como artéria cerebral caudal. Esta se projetou látero-dorsalmente e ao sobrepassar o trato óptico, emitiu seu I (primeiro) ramo central. Penetrou na fissura transversa do cérebro, lançando a artéria diencefálica e a seguir seu II (segundo) ramo central. Thirty heads with the neck segment of Caiman latirostris were used. The animals were provided from a creation center called Mister Caiman, under the authorization of the Brazilian Institute of Environment and Renewable Natural Resources (Ibama). Animals were sacrificed according to the slaughtering routine of the abattoir, and the heads were sectioned at the level of the third cervical vertebra. The arterial system was washed with cold saline solution, with drainage through jugular veins. Subsequently, the system was filled with red colored latex injection. Pieces were than fixed in 20% formaldehyde, for seven days. The brains were removed, with a spinal cord segment, the duramater removed and the arteries dissected. At the level of the hypophysis, the internal carotid artery gave off a rostral branch, and a short caudal branch, continuing, naturally, as the caudal cerebral artery. This artery projected laterodorsalwards and, as it overpassed the optic tract, gave off its I (the first) central branch. Penetrated in the cerebral transverse fissure, emitting the diencephalic artery and next its II (second) central branch. Still inside the fissure, originated occipital hemispheric branches and a pineal branch. Emerged from the cerebral transverse fissure, over the occipital pole of the cerebral hemisphere. Projected rostralwards, sagital to the cerebral longitudinal fissure, as interhemispheric artery. This artery gave off medial and convex hemispheric branches to the respective surfaces of the cerebral hemispheres, anastomosed with its contralateral homologous, forming the common ethmoidal artery. This artery entered the fissure between the olfactory peduncles, emerging ventrally and dividing into ethmoidal arteries, ri...

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