Systematization, distribution, and territories of the caudal cerebral artery on the surface of the brain in nutria (Myocastor coypus) / Sistematização, distribuição e territórios da artéria cerebral caudal na superfície do cérebro em Nutria (Myocastor coypus)

The nutria (Myocastor coypus) is a medium-sized, semi-aquatic rodent valued by the skin and meat industry. This study aimed to describe and systematize the caudal cerebral artery on the brain surface in nutria, establishing a standard model and its main variations in this species. The thirty animals used were euthanized according to animal welfare rules. The vessels were filled with latex stained with red pigment and the samples were fixed in formaldehyde. In nutria, the brain was vascularized by the vertebral basilar system. The terminal branches of the basilar artery originated the rostral cerebellar, caudal cerebral, rostral choroidal and middle cerebral arteries, and its terminal branch, the rostral cerebral artery. The terminal branch of the basilar artery projected the caudal cerebral artery, which is usually a single medium-caliber vessel, into the transverse fissure of the brain. The caudal cerebral artery was presented as a single (66.7% of the cases to the right and 76.7% to the left) and double vessel (33.3% of the cases to the right and 23.3% to the left). It originated the rostral mesencephalic artery, the proximal component, and the caudal inter-hemispheric artery. The terminal branches of the rostral and caudal tectal mesencephalic arteries formed a typical anastomotic network. The caudal inter-hemispheric artery emitted central branches, the caudal choroidal artery, hemispherical occipital arteries, rostral tectal mesencephalic branches and distal components, and anastomosed "in osculum" with the terminal branches of the rostral inter-hemispheric artery. The caudal choroidal artery anastomosed with the rostral choroidal artery, where it branched out on the thalamic mass, vascularizing all diencephalic structures and the hippocampus. The caudal cerebral artery and its terminal branches anastomosed with the terminal branches of the rostral and middle cerebral arteries in a restricted region of the caudal pole of the cerebral hemisphere. The vascularization area of the caudal cerebral artery and its central branches in the paleopallial of the piriform lobe is extremely restricted, caudomedially.(AU)

A nutria (Myocastor coypus) é um roedor semi-aquático de tamanho mediano, apreciado na indústria de peles e carne. Este trabalho tem por objetivo descrever e sistematizar a artéria cerebral caudal na superfície do cérebro em nutria, estabelecendo um modelo padrão e suas principais variações e territórios nesta espécie. Os trinta animais utilizados foram eutanasiados segundo as regras de bem-estar animal, os vasos foram preenchidos com látex, corado em vermelho e as peças foram fixadas em formoldeído. O cérebro foi vascularizado exclusivamente pelo sistema vértebro-basilar. Os ramos terminais da artéria basilar originaram as artérias cerebelar rostral, cerebral caudal, corióidea rostral, cerebral média e seu ramo terminal, a artéria cerebral rostral. O ramo terminal da artéria basilar lançou a artéria cerebral caudal, um vaso normalmente único, de médio calibre, para o interior da fissura transversa do cérebro. A artéria cerebral caudal foi um vaso único em 66,7% à direita e em 76,7% à esquerda e mostrou-se dupla em 33,3% à direita e em 23,3% à esquerda. Ela lançou a artéria tectal mesencefálica rostral, componente proximal e a artéria inter-hemisférica caudal. Os ramos terminais das artérias tectais mesencefálicas, rostral e caudal, formavam uma rede anastomótica típica. A artéria inter-hemisférica caudal lançou ramos centrais, a artéria corióidea caudal, as artérias hemisféricas occipitais, os ramos tectais mesencefálicos rostrais, componentes distais e anastomosou-se "em ósculo" com o ramo terminal da artéria inter-hemisférica rostral. A artéria corióidea caudal anastomosava-se com a artéria corióidea rostral, onde ramificavam-se sobre a massa talâmica, vascularizando todas as estruturas do diencéfalo e hipocampo. A artéria cerebral caudal com seus ramos terminais apresenta anastomoses com os ramos terminais das artérias cerebrais rostral e média em uma região restrita do pólo caudal do hemisfério cerebral. A área de vascularização da artéria cerebral caudal com seus ramos centrais no páleo-palio do lobo piriforme é extremamente restrita, caudo-medialmente ao mesmo.(AU)

Systematization, distribution, and territories of the caudal cerebral artery on the surface of the brain in nutria (Myocastor coypus) / Sistematização, distribuição e territórios da artéria cerebral caudal na superfície do cérebro em Nutria (Myocastor coypus)

The nutria (Myocastor coypus) is a medium-sized, semi-aquatic rodent valued by the skin and meat industry. This study aimed to describe and systematize the caudal cerebral artery on the brain surface in nutria, establishing a standard model and its main variations in this species. The thirty animals used were euthanized according to animal welfare rules. The vessels were filled with latex stained with red pigment and the samples were fixed in formaldehyde. In nutria, the brain was vascularized by the vertebral basilar system. The terminal branches of the basilar artery originated the rostral cerebellar, caudal cerebral, rostral choroidal and middle cerebral arteries, and its terminal branch, the rostral cerebral artery. The terminal branch of the basilar artery projected the caudal cerebral artery, which is usually a single medium-caliber vessel, into the transverse fissure of the brain. The caudal cerebral artery was presented as a single (66.7% of the cases to the right and 76.7% to the left) and double vessel (33.3% of the cases to the right and 23.3% to the left). It originated the rostral mesencephalic artery, the proximal component, and the caudal inter-hemispheric artery. The terminal branches of the rostral and caudal tectal mesencephalic arteries formed a typical anastomotic network. The caudal inter-hemispheric artery emitted central branches, the caudal choroidal artery, hemispherical occipital arteries, rostral tectal mesencephalic branches and distal components, and anastomosed "in osculum" with the terminal branches of the rostral inter-hemispheric artery. The caudal choroidal artery anastomosed with the rostral choroidal artery, where it branched out on the thalamic mass, vascularizing all diencephalic structures and the hippocampus. The caudal cerebral artery and its terminal branches anastomosed with the terminal branches of the rostral and middle cerebral arteries in a restricted region of the caudal pole of the cerebral hemisphere. The vascularization area of the caudal cerebral artery and its central branches in the paleopallial of the piriform lobe is extremely restricted, caudomedially.(AU)

A nutria (Myocastor coypus) é um roedor semi-aquático de tamanho mediano, apreciado na indústria de peles e carne. Este trabalho tem por objetivo descrever e sistematizar a artéria cerebral caudal na superfície do cérebro em nutria, estabelecendo um modelo padrão e suas principais variações e territórios nesta espécie. Os trinta animais utilizados foram eutanasiados segundo as regras de bem-estar animal, os vasos foram preenchidos com látex, corado em vermelho e as peças foram fixadas em formoldeído. O cérebro foi vascularizado exclusivamente pelo sistema vértebro-basilar. Os ramos terminais da artéria basilar originaram as artérias cerebelar rostral, cerebral caudal, corióidea rostral, cerebral média e seu ramo terminal, a artéria cerebral rostral. O ramo terminal da artéria basilar lançou a artéria cerebral caudal, um vaso normalmente único, de médio calibre, para o interior da fissura transversa do cérebro. A artéria cerebral caudal foi um vaso único em 66,7% à direita e em 76,7% à esquerda e mostrou-se dupla em 33,3% à direita e em 23,3% à esquerda. Ela lançou a artéria tectal mesencefálica rostral, componente proximal e a artéria inter-hemisférica caudal. Os ramos terminais das artérias tectais mesencefálicas, rostral e caudal, formavam uma rede anastomótica típica. A artéria inter-hemisférica caudal lançou ramos centrais, a artéria corióidea caudal, as artérias hemisféricas occipitais, os ramos tectais mesencefálicos rostrais, componentes distais e anastomosou-se "em ósculo" com o ramo terminal da artéria inter-hemisférica rostral. A artéria corióidea caudal anastomosava-se com a artéria corióidea rostral, onde ramificavam-se sobre a massa talâmica, vascularizando todas as estruturas do diencéfalo e hipocampo. A artéria cerebral caudal com seus ramos terminais apresenta anastomoses com os ramos terminais das artérias cerebrais rostral e média em uma região restrita do pólo caudal do hemisfério cerebral. A área de vascularização da artéria cerebral caudal com seus ramos centrais no páleo-palio do lobo piriforme é extremamente restrita, caudo-medialmente ao mesmo.(AU)

Vascularization of the Alouatta belzebul brain base / Vascularização da base do encéfalo de Alouatta belzebul

We studied the arterial circle in the brain of five specimens of the Alouatta belzebul primate. The material had the arterial system perfused (water at 40°C), injected with stained latex (Neoprene 650), fixed in aqueous formaldehyde solution (10%) and dissected for vessel verification. The arterial circle of this primate is composed of two vascular systems: the vertebra-basilar and the carotid ones, which anastomose to close the arterial circuit. In the caudal portion of the arterial circle, there are the vertebral arteries and their branches: the rostral spinal artery and the caudal inferior cerebellar artery. The anastomosis of the vertebral arteries gives rise to the basilar artery. It presented an anatomical variation at the beginning of its path, forming a double basilar artery, called arterial island. In its course, it emitted branches giving rise to the rostral inferior cerebellar artery, the pontine arteries, the rostral cerebellar arteries, the satellite rostral cerebellar arteries and its terminal branch, the caudal cerebral artery, which presented itself in two segments: the pre-communicating one and post-communicating, joining the internal carotid artery and originating the caudal communicating artery. This group of arteries and anastomoses enclose the caudal portion of the arterial circle. From the right and left internal carotid arteries begins the rostral portion of the arterial circle, which consists of the right and left rostral cerebral arteries and the right and left middle cerebral arteries. The rostral cerebral arteries anastomose into a single trunk, giving rise to the interhemispheric artery, and in A. belzebul and Sapajus libidinosus, the rostral communicating artery is absent. The interhemispheric artery goes to the midbrain region and the corpus callosum knee divides into pericalous artery and callosarginal artery, which will supply the pre and post-central regions of the cerebral hemispheres of this species, as well as other non-human and human primates. It is noted that in the first part of the left rostral cerebral artery, there is a direct inosculation between the recurrent branch of the rostral cerebral artery and left middle cerebral artery to supply the entorhinal region. This fact also occurs in Pongo spp. The middle cerebral artery travels along the lateral sulcus where it emits several superficial branches to irrigate the superior and inferior lateral cortical regions of the frontal, parietal and temporal lobes. It is not part of the arterial circle but is the terminal branch of the internal carotid artery. A. belzebul can be considered to depend on two sources of supply to the brain: the vertebra-basilar and carotid systems, contributing to the intervention of veterinarians during clinical and surgical procedures in other primates, as well as the preservation of wild animals.(AU)

Estudamos o círculo arterial no encéfalo de cinco espécimes do primata Alouatta belzebul. O material teve o sistema arterial perfundido (água a 40°C), injetado com látex corado (Neoprene 650), fixado em solução aquosa de formaldeído (10%) e dissecado para verificação dos vasos. O círculo arterial deste primata é composto por dois sistemas vasculares: vértebro-basilar e o sistema carotídeo, que se anastomosam para fechar o circuito arterial. Na porção caudal do círculo arterial encontra-se as artérias vertebrais e seus ramos: artéria espinal rostral e a cerebelar inferior caudal. A anastomose das artérias vertebrais dá origem a artéria basilar. Esta apresentou uma variação anatômica no início do seu trajeto, formando uma dupla artéria basilar, denominada ilha arterial. Em seu trajeto emitiu ramos dando origem a artéria cerebelar inferior rostral, as artérias pontinas, as artérias cerebelares rostrais, as artérias cerebelares rostrais satélites e o seu ramo terminal, a artéria cerebral caudal, que apresentou-se em dois segmentos: o pré-comunicante e pós-comunicante, unindo-se a artéria carótida interna e originando a artéria comunicante caudal. Este grupo de artérias e anastomoses encerram a porção caudal do círculo arterial. Das artérias carótidas internas direita e esquerda, inicia-se a porção rostral do círculo arterial, ao qual é constituído pelas artérias cerebrais rostrais direita e esquerda e as artérias cerebrais médias direita e esquerda. As artérias cerebrais rostrais se anastomosam em um tronco único dando origem a artéria inter-hemisférica e em A. belzebul e Sapajus libidinosus, a artéria comunicante rostral se encontra ausente. A artéria inter-hemisférica segue para região média do encéfalo e no joelho do corpo caloso se divide em artéria pericalosa e artéria calosomarginal, que vão suprir as regiões pré e pós-central dos hemisférios cerebrais desta espécie, assim como outros primatas não humanos e humano. Nota-se que na primeira parte da artéria cerebral rostral esquerda, ocorre uma inosculação direta entre o ramo recorrente da artéria cerebral rostral e artéria cerebral média esquerda para suprir a região entorrinal, esse fato também ocorre em Pongo spp. A artéria cerebral média segue seu trajeto pelo sulco lateral onde emite vários ramos superficiais para irrigar as regiões corticais supero e ínfero lateral do lobo frontal, parietal e temporal, esta não faz parte do círculo arterial mas é o ramo terminal da artéria carótida interna. Pode-se considerar que A. belzebul depende de duas fontes de suprimento para o encéfalo: os sistemas vértebro-basilar e carotídeo, contribuindo na intervenção de médicos veterinários durante os procedimentos clínicos e cirúrgicos em outros primatas, assim como na preservação de animais silvestres.(AU)

Anatomic study of the arterial vascularization of the brain base of paca (Cuniculus paca) / Estudo anatômico da vascularização arterial da base do encéfalo da paca (Cuniculus paca)

Paca (Cuniculus paca Linnaeus, 1766), rodent belong to the Cuniculidae family, has encouraged numerous scientific researches and for this reason could be an experimental model in both human and veterinary areas. And recently, the economic exploitation of the meat cuts, has being direct implication in its zootechnical importance. However, no anatomical descriptions regarding the vascularization of the base of the brain in this rodent has being found. Thus, the aim of the present study was to describe the arteries and the pattern of the vasculature and to compare it with the other species already established in the literature. For this, five pacas, donated by the Unesp Jaboticabal Wildlife Sector, were euthanized followed by the vascular arterial system was injected with red-stained-centrifuged latex by the common carotid artery. After craniectomy, the brains were removed and the arteries were identified and, in addition, compared with those described in other animal species. The presence of the right and left vertebral arteries, close to the medulla oblongata, was detected, originating the basilar artery, which divided into the terminal branches of the right and left basilar artery. Ventral to the optic tract there was the right internal carotid artery and the left, dividing the middle cerebral artery and left rostral and right; dorsal to the optic chiasm, the medial branch of the rostral cerebral arteries was identified. Based on the results, it is concluded that the vascularization of the paca brain base is supplied by the carotid and vertebrobasilar system.(AU)

A paca (Cuniculus paca Linnaeus 1766), roedor da família Cuniculidae, tem encorajado inúmeras pesquisas científicas, tornando-a modelo experimental tanto na área humana quanto na veterinária, além da recente exploração econômica de seus cortes cárneos, que favoreceu diretamente sua importância zootécnica. No entanto, não há até o momento, descrições anatômicas referentes à padronização da vascularização da base do encéfalo neste roedor. Assim, o objetivo do presente trabalho foi realizar tal delineamento arterial nessa região do sistema nervoso central e compará-lo com as demais espécies já estabelecidas na literatura. Para isso, foram eutanasiadas cinco pacas doadas pelo setor de Animais Silvestres da Unesp Jaboticabal, as quais foram submetidas posteriormente à injeção de látex centrifugado e corante líquido xadrez vermelho, pela artéria carótida comum. Após craniectomia e segregação do encéfalo de todos os cadáveres, realizou-se a identificação das artérias presentes na base deste órgão e, ademais, comparação destas com as descritas cientificamente em outras espécies animais. Detectou-se a presença das artérias vertebral direita e esquerda, próximas à medula oblonga, originando a artéria basilar, que se dividiu nos ramos terminais da artéria basilar direito e esquerdo. Ventral ao trato óptico verificou-se a artéria carótida interna direita e esquerda dividindo-se na artéria cerebral média e rostral direita e esquerda; ainda, dorsal ao quiasma óptico, identificou-se o ramo medial das artérias cerebrais rostrais. Com base nos resultados obtidos, conclui-se que a vascularização da base do encéfalo da paca é suprida pelo sistema carotídeo e vertebro-basilar.(AU)

Anatomic study of the arterial vascularization of the brain base of paca (Cuniculus paca) / Estudo anatômico da vascularização arterial da base do encéfalo da paca (Cuniculus paca)

Paca (Cuniculus paca Linnaeus, 1766), rodent belong to the Cuniculidae family, has encouraged numerous scientific researches and for this reason could be an experimental model in both human and veterinary areas. And recently, the economic exploitation of the meat cuts, has being direct implication in its zootechnical importance. However, no anatomical descriptions regarding the vascularization of the base of the brain in this rodent has being found. Thus, the aim of the present study was to describe the arteries and the pattern of the vasculature and to compare it with the other species already established in the literature. For this, five pacas, donated by the Unesp Jaboticabal Wildlife Sector, were euthanized followed by the vascular arterial system was injected with red-stained-centrifuged latex by the common carotid artery. After craniectomy, the brains were removed and the arteries were identified and, in addition, compared with those described in other animal species. The presence of the right and left vertebral arteries, close to the medulla oblongata, was detected, originating the basilar artery, which divided into the terminal branches of the right and left basilar artery. Ventral to the optic tract there was the right internal carotid artery and the left, dividing the middle cerebral artery and left rostral and right; dorsal to the optic chiasm, the medial branch of the rostral cerebral arteries was identified. Based on the results, it is concluded that the vascularization of the paca brain base is supplied by the carotid and vertebrobasilar system.(AU)

A paca (Cuniculus paca Linnaeus 1766), roedor da família Cuniculidae, tem encorajado inúmeras pesquisas científicas, tornando-a modelo experimental tanto na área humana quanto na veterinária, além da recente exploração econômica de seus cortes cárneos, que favoreceu diretamente sua importância zootécnica. No entanto, não há até o momento, descrições anatômicas referentes à padronização da vascularização da base do encéfalo neste roedor. Assim, o objetivo do presente trabalho foi realizar tal delineamento arterial nessa região do sistema nervoso central e compará-lo com as demais espécies já estabelecidas na literatura. Para isso, foram eutanasiadas cinco pacas doadas pelo setor de Animais Silvestres da Unesp Jaboticabal, as quais foram submetidas posteriormente à injeção de látex centrifugado e corante líquido xadrez vermelho, pela artéria carótida comum. Após craniectomia e segregação do encéfalo de todos os cadáveres, realizou-se a identificação das artérias presentes na base deste órgão e, ademais, comparação destas com as descritas cientificamente em outras espécies animais. Detectou-se a presença das artérias vertebral direita e esquerda, próximas à medula oblonga, originando a artéria basilar, que se dividiu nos ramos terminais da artéria basilar direito e esquerdo. Ventral ao trato óptico verificou-se a artéria carótida interna direita e esquerda dividindo-se na artéria cerebral média e rostral direita e esquerda; ainda, dorsal ao quiasma óptico, identificou-se o ramo medial das artérias cerebrais rostrais. Com base nos resultados obtidos, conclui-se que a vascularização da base do encéfalo da paca é suprida pelo sistema carotídeo e vertebro-basilar.(AU)

Vascularization of the Alouatta belzebul brain base / Vascularização da base do encéfalo de Alouatta belzebul

We studied the arterial circle in the brain of five specimens of the Alouatta belzebul primate. The material had the arterial system perfused (water at 40°C), injected with stained latex (Neoprene 650), fixed in aqueous formaldehyde solution (10%) and dissected for vessel verification. The arterial circle of this primate is composed of two vascular systems: the vertebra-basilar and the carotid ones, which anastomose to close the arterial circuit. In the caudal portion of the arterial circle, there are the vertebral arteries and their branches: the rostral spinal artery and the caudal inferior cerebellar artery. The anastomosis of the vertebral arteries gives rise to the basilar artery. It presented an anatomical variation at the beginning of its path, forming a double basilar artery, called arterial island. In its course, it emitted branches giving rise to the rostral inferior cerebellar artery, the pontine arteries, the rostral cerebellar arteries, the satellite rostral cerebellar arteries and its terminal branch, the caudal cerebral artery, which presented itself in two segments: the pre-communicating one and post-communicating, joining the internal carotid artery and originating the caudal communicating artery. This group of arteries and anastomoses enclose the caudal portion of the arterial circle. From the right and left internal carotid arteries begins the rostral portion of the arterial circle, which consists of the right and left rostral cerebral arteries and the right and left middle cerebral arteries. The rostral cerebral arteries anastomose into a single trunk, giving rise to the interhemispheric artery, and in A. belzebul and Sapajus libidinosus, the rostral communicating artery is absent...(AU)

Estudamos o círculo arterial no encéfalo de cinco espécimes do primata Alouatta belzebul. O material teve o sistema arterial perfundido (água a 40°C), injetado com látex corado (Neoprene 650), fixado em solução aquosa de formaldeído (10%) e dissecado para verificação dos vasos. O círculo arterial deste primata é composto por dois sistemas vasculares: vértebro-basilar e o sistema carotídeo, que se anastomosam para fechar o circuito arterial. Na porção caudal do círculo arterial encontra-se as artérias vertebrais e seus ramos: artéria espinal rostral e a cerebelar inferior caudal. A anastomose das artérias vertebrais dá origem a artéria basilar. Esta apresentou uma variação anatômica no início do seu trajeto, formando uma dupla artéria basilar, denominada ilha arterial. Em seu trajeto emitiu ramos dando origem a artéria cerebelar inferior rostral, as artérias pontinas, as artérias cerebelares rostrais, as artérias cerebelares rostrais satélites e o seu ramo terminal, a artéria cerebral caudal, que apresentou-se em dois segmentos: o pré-comunicante e pós-comunicante, unindo-se a artéria carótida interna e originando a artéria comunicante caudal. Este grupo de artérias e anastomoses encerram a porção caudal do círculo arterial. Das artérias carótidas internas direita e esquerda, inicia-se a porção rostral do círculo arterial, ao qual é constituído pelas artérias cerebrais rostrais direita e esquerda e as artérias cerebrais médias direita e esquerda. As artérias cerebrais rostrais se anastomosam em um tronco único dando origem a artéria inter-hemisférica e em A. belzebul e Sapajus libidinosus, a artéria comunicante rostral se encontra ausente. A artéria inter-hemisférica segue para região média do encéfalo e no joelho do corpo caloso se divide em artéria pericalosa e artéria calosomarginal, que vão suprir as regiões pré e pós-central dos hemisférios cerebrais desta espécie, assim como outros primatas não humanos e humano...(AU)

Telencephalon vascularity in sheep (Ovis aries)

The studies into the vascularity of the telencephalon in Polish Merino sheep of both sexes were made on 60 cerebral hemispheres. It was found that the middle cerebral artery is the most powerful vessel supplying blood to the telencephalon. The artery gets divided into ten permanent branches. Two olfactory arteries supply the area of the telencephalon located on the border between the old and the new cortex. The other eight branches get divided into three branches running to the region of the frontal lobus of the brain, two branches - to the region of the parietal lobus and three temporal branches heading for the temporal region, supplying blood to the new cortex only. The frontal, parietal and temporal branches descended independently from the main trunk of the middle cerebral artery or first formed a common trunk. Common trunks for respective groups of branches have been referred to as: the anterior, superior and posterior middle cerebral arteries. The posterior olfactory artery in 6.7% of the cases was an independent branch from the rostral cerebral artery.(AU)

Telencephalon vascularity in sheep (Ovis aries)

The studies into the vascularity of the telencephalon in Polish Merino sheep of both sexes were made on 60 cerebral hemispheres. It was found that the middle cerebral artery is the most powerful vessel supplying blood to the telencephalon. The artery gets divided into ten permanent branches. Two olfactory arteries supply the area of the telencephalon located on the border between the old and the new cortex. The other eight branches get divided into three branches running to the region of the frontal lobus of the brain, two branches - to the region of the parietal lobus and three temporal branches heading for the temporal region, supplying blood to the new cortex only. The frontal, parietal and temporal branches descended independently from the main trunk of the middle cerebral artery or first formed a common trunk. Common trunks for respective groups of branches have been referred to as: the anterior, superior and posterior middle cerebral arteries. The posterior olfactory artery in 6.7% of the cases was an independent branch from the rostral cerebral artery.(AU)

Vascularização arterial da base do encéfalo do gerbil (Meriones unguiculatus Milne-Edwards, 1867) / Arterial vascularization of the base of the cerebrum of mongolian gerbils(Meriones unguiculatus Milne-Edwards, 1867)

Objetivou-se descrever e sistematizar as artérias da base do encéfalo. Foram utilizados dez gerbils que se encontravamarmazenados em freezer no laboratório de Morfofisiologia Animal Aplicada da Universidade Federal Rural do Semiárido. Osanimais foram descongelados, incisados na linha mediana para identificação do ventrículo esquerdo, o qual foi perfurado einjetados 3ml de Látex Neoprene 650 na concentração de 20% e no pigmento vermelho. Posteriormente aguardou-se cerca de 1minuto em virtude da polimerização do Látex e logo após foram fixados por imersão em solução aquosa de Formaldeído a 3,7% eapós 72 horas, tiveram os encéfalos removidos da calota craniana para análise de sua superfície ventral. Foi visto que o sistemavertebrobasilar e carótico estiveram presentes em todos os animais analisados, mostrando-se responsável pela vascularizaçãodo encéfalo caudal e rostral, respectivamente. As principais artérias observadas no modelo padrão incluem as ímpares: basilar,espinhal ventral, ramo medial da artéria cerebral rostral e as pares: vertebral, cerebelar caudal, cerebelar média, trigeminal,cerebelar rostral, ramo terminal da basilar, carótida interna, cerebral caudal, hipofisária, cerebral média, cerebral rostral, lateral dobulbo olfatório e etmoidal interna. Conclui-se com base nos resultados que a irrigação da superfície ventral encefálica do gerbilfoi suprida pelos sistemas vertebro-basilar e carótico de forma equivalente, pertencendo assim ao modelo do tipo II. O circuitoarterioso apresentou-se aberto caudalmente e fechado rostralmente, fato que difere do relatado em roedores como capivara,cutia, preá, chinchila e nutria.(AU)

The objective was to describe and systematize the arteries of the base of the brain. Ten gerbils were used, which were stored in afreezer in the Laboratory of Applied Animal Morphophysiology of the Federal Rural Semi-Arid University. The animals were thawed,incised in the midline to identify the left ventricle, which was punctured and injected 3 ml of Latex Neoprene 650 at a concentrationof 20% and red pigment. After about one minute the polymerization of the Latex was delayed and afterwards fixed by immersionin 3.7% aqueous Formaldehyde solution and after 72 hours the brain was removed from the skull cap for analysis of its ventralsurface. It was observed that the vertebro-basilar and carotid system were present in all animals analyzed, being responsible forthe vascularization of the caudal and rostral encephalon, respectively. The main arteries observed in the standard model includethe odd: basilar, ventral spinal, medial branch of the rostral cerebral artery and, the pairs: vertebral, cerebellar caudal, cerebellarmedial, trigeminal, cerebellar rostral, terminal branch of the basilar, internal carotid, caudal cerebral, Pituitary, middle cerebral, rostral,lateral, olfactory and internal ethmoidal. Based on the results, the irrigation of the ventral brain surface of the gerbil was suppliedby the vertebro-basilar and carotic systems in an equivalent way, thus belonging to the type II model. The arterial circuit was opencaudally and closed rostrally, a fact that differs from that reported in rodents such as capybara, agouti, cavy, chinchilla and nutria.(AU)

Cortical branches of the middle cerebral artery in silver fox (Vulpes vulpes)

The study of the vascularization of the cerebrum in silver fox was performed on 80 cerebral hemispheres. It was found that the middle cerebral artery is the strongest vessel supplying blood to the cerebrum. The artery gets divided into ten permanent branches. Two olfactory arteries supply the region of the cerebrum located on the border between the old and the new cortex. The other eight supply the region of the new cortex. The frontal, parietal and temporal branches descended independently from the main trunk of the middle cerebral artery or formed a common trunk. Common trunks for respective groups of branches have been described as the anterior, superior and posterior middle cerebral artery. The alterior olfactory artery in 5% of cases and posterior olfactory artery in 2.5% of cases were independent branches of the middle cerebral artery extending from the rostral cerebral artery.(AU)

Cortical branches of the middle cerebral artery in silver fox (Vulpes vulpes)

The study of the vascularization of the cerebrum in silver fox was performed on 80 cerebral hemispheres. It was found that the middle cerebral artery is the strongest vessel supplying blood to the cerebrum. The artery gets divided into ten permanent branches. Two olfactory arteries supply the region of the cerebrum located on the border between the old and the new cortex. The other eight supply the region of the new cortex. The frontal, parietal and temporal branches descended independently from the main trunk of the middle cerebral artery or formed a common trunk. Common trunks for respective groups of branches have been described as the anterior, superior and posterior middle cerebral artery. The alterior olfactory artery in 5% of cases and posterior olfactory artery in 2.5% of cases were independent branches of the middle cerebral artery extending from the rostral cerebral artery.(AU)

Systematization, description, and territory of the middle cerebral artery in brain surface of the turtle (Trachemys scripta elegans) / Sistematização, descrição e território da artéria cerebral média na superfície do cérebro em tartaruga (Trachemys scripta elegans)

Background: Trachemys scripta elegans, in Brazil, has been considered an exotic and invasive turtle; it competes with autochthon species for habitat and food, threatening biodiversity. These animals have been exported to Brazil as pets; however, despite of the commercial interest in the last years, there are only few reports about the turtle central nervous system vascularization. Therefore, this study had the objective to describe and systematize the middle cerebral artery at the brain surface of the turtle (Trachemys scripta elegans), determining a standard model of irrigation and the main ramifications and territory, in this species. Materials, Methods & Results: Thirty turtles received pre-anesthetic medication composed of ketamine (80 mg/kg) and midazolam (2 mg/kg) followed by euthanasia with a sodium thiopental (100 mg/kg) overdose. The aortic arches were cannulated through the single ventricle, the cranial cava veins were incised and the vascular system washed with saline solution and heparin, and then filled with latex. Pieces remained immersed in running water and a bone window was opened in the cranial vault. Samples were fixed with formaldehyde and each brain with a spinal cord segment was removed from the cranial vault, the duramater was removed and the arteries dissected. Results were recorded and it was observed that the middle cerebral artery, collateral [...](AU)

Systematization, description, and territory of the middle cerebral artery in brain surface of the turtle (Trachemys scripta elegans) / Sistematização, descrição e território da artéria cerebral média na superfície do cérebro em tartaruga (Trachemys scripta elegans)

Background: Trachemys scripta elegans, in Brazil, has been considered an exotic and invasive turtle; it competes with autochthon species for habitat and food, threatening biodiversity. These animals have been exported to Brazil as pets; however, despite of the commercial interest in the last years, there are only few reports about the turtle central nervous system vascularization. Therefore, this study had the objective to describe and systematize the middle cerebral artery at the brain surface of the turtle (Trachemys scripta elegans), determining a standard model of irrigation and the main ramifications and territory, in this species. Materials, Methods & Results: Thirty turtles received pre-anesthetic medication composed of ketamine (80 mg/kg) and midazolam (2 mg/kg) followed by euthanasia with a sodium thiopental (100 mg/kg) overdose. The aortic arches were cannulated through the single ventricle, the cranial cava veins were incised and the vascular system washed with saline solution and heparin, and then filled with latex. Pieces remained immersed in running water and a bone window was opened in the cranial vault. Samples were fixed with formaldehyde and each brain with a spinal cord segment was removed from the cranial vault, the duramater was removed and the arteries dissected. Results were recorded and it was observed that the middle cerebral artery, collateral [...]

Arterial vascularization of the brain of the agouti (Dasyprocta aguti Linnaeus, 1766) / Vascularização arterial da base do encéfalo de cutias (Dasyprocta aguti Linnaeus, 1766)

The agouti, a rodent that is geographically distributed throughout South America, is greatly valued for its meat. This paper describes the arterial vascularization of the base of the agoutis brain, characterizing behavior, and arterial origin and distribution. Ten animals from the Center for the Multiplication of Wild Animals (CEMAS/UFERSA) were used and the study was approved by SISBIO (report number 32413-1) and the Ethics Committee on Animal Use (CEUA/UFERSA) (protocol 02/2010). After euthanasia, the animals were incised in the thoracic cavity by an injection of red-stained Neoprene latex 650 and the skulls were subsequently opened. The brains were extracted from the skulls for ventral surface analysis and then fixed in an aqueous 10% formaldehyde solution. The agoutis arterial vascularization of the brain has two main components, namely the carotid and vertebrobasilar systems. The agoutis carotid system accounts for vascularization of almost the entire forebrain, while the vertebrobasilar system accounts for vascularization of almost the entire posterior brain (medulla oblongata, pyramid, trapezoid body, cerebellum, bridge, and part of the third caudal section of the forebrain) through the caudal cerebral arteries originating from the terminal branches of the basilar artery. The main arteries on the brain surface include the basilar artery, which is unique, and the arterial pairs, specifically the vertebral arteries, cerebellar caudal arteries, trigeminal artery, rostral cerebellar artery, basilar terminal branch artery, cerebral caudal artery, communicating caudal branch of the cerebral carotid artery, cerebral carotid artery, communicating branch rostral cerebral carotid artery, choroidal rostral artery, medial branch of the communicating branch rostral artery, internal ophthalmic artery, middle cerebral artery, and rostral cerebral artery.(AU)

A cutia é um roedor, que se distribui geograficamente por quase toda América Latina, sendo apreciada pelo sabor da sua carne. Neste trabalho objetivou-se descrever a vascularização arterial da base do encéfalo de cutias, caracterizando o comportamento, origem e distribuição das artérias componentes. Foram utilizados 10 animais do Centro de Multiplicação de Animais Silvestres (CEMAS/UFERSA), pesquisa aprovada pela Comissão de Ética no Uso de Animais (CEUA/ UFERSA- n° 02/2010) e pelo SISBIO (N°32413-1). Após eutanásia, os animais foram incisados na cavidade torácica para injeção de Neoprene látex 650 corado na cor vermelha e posterior abertura da calota craniana. Os encéfalos foram extraídos do crânio para análise da sua face ventral e logo fixados em solução aquosa de formaldeído a 10%. A vascularização arterial do encéfalo da cutia apresenta dois componentes principais, o sistema carótico e o vértebro-basilar. O sistema carótico na cutia é responsável pela vascularização do cérebro anterior em quase sua totalidade. O sistema vértebro-basilar é responsável pela vascularização do cérebro posterior (medula oblonga, pirâmide, corpo trapezóide, o cerebelo e ponte e parte do terço caudal do cérebro anterior), através das artérias cerebrais caudais, originárias dos ramos terminais da artéria basilar. As principais artérias presentes na superfície do encéfalo incluem a basilar que é ímpar, e as pares: artérias vertebrais, cerebelar caudal, trigemial, cerebelar rostral, ramo terminal da basilar, cerebral caudal, ramo comunicante caudal da carótida cerebral, carótida cerebral, ramo comunicante rostral da carótida cerebral, corióidearostral, ramo medial do ramo comunicante rostral, oftálmica interna, cerebral média e artéria cerebral rostral.(AU)

AVALIAÇÃO DOS VALORES HEMODINÂMICOS PRESUMIDAMENTE NORMAIS DA ARTÉRIA UMBILICAL, ARTÉRIA CARÓTIDA INTERNA E ARTÉRIA CEREBRAL MÉDIA FETAL NO TERÇO FINAL GESTACIONAL EM CADELAS

A ultrassonografia bidimensional com Doppler possibilita a avaliação de índices vasculares do fluxo sanguíneo na avaliação gestacional, bem como permite a caracterização hemodinâmica por meio da determinação de valores de resistência vascular, como o índice de resistividade (IR) e índice de pulsatilidade (IP), obtidos pela mensuração da velocidade de pico sistólica (VPS) e da velocidade diastólica final (VDF). O estudo visa definir valores hemodinamicamente normais da artéria umbilical (cordão umbilical- CU), artéria uteroplacentária (AUP), artéria média cerebral (ACM) e artéria carótida comum (ACC) dos fetos, de cadelas no terço final de gestação, bem como correlaciona-los entre si, para predizer indiretamente a viabilidade fetal e data provável do parto. Foram avaliadas 30 cadelas no terço final da gestação (40 - 60 dias), clinicamente saudáveis. Estas foram submetidas a avaliação ultrassonográfica dopplervelocimétrica em dois períodos, o primeiro, entre 40-50 dias e o segundo, entre 51-60 dias de gestação. Em cada período foi analisado os índices de pulsatilidade e resistividade da CU, AUP, ACM e a ACC fetos. Todos os dados obtidos foram submetidos à análise de variância e ao Teste de Tukey, utilizando o P valor de 5%. As velocidades de pico sistólico (VPS) e a velocidade diastólica final (VDF) demonstraram aumento progressivo ao longo do tempo de estudo. Consequentemente, a relação S/D apresentou diminuição entre os períodos estudados. A análise dos índices de resistividade (IR) e pulsatilidade (IP) do CU, demonstraram diminuição entre os períodos 1 e 2. Semelhante, na AUP, os valores de VPS e VDF evidenciaram aumento entre tempos, enquanto a relação S/D diminuiu. Para a ACM e artéria carótida interna, os valores de VPS e VDF apresentaram-se crescentes até o final da gestação. A análise da relação cerebroplacentária (ACM/AU) demonstrou valores decrescentes entre os períodos P1 e P2, demonstrando diferença estatística significante (P < 0,05). As velocidades de fluxo vascular da AUP, CU, ACM e ACC mostraram valores semelhantes aos previamente descritos na literatura para cadelas em curso normal de gestação. Os dados obtidos no presente estudo podem ser úteis na identificação da centralização fetal, contribuindo na caracterização da viabilidade fetal, fornecendo dados valiosos para a programação mais efetiva do parto por cesariana, aumentando a sobrevida dos recém-nascidos.

Two-dimensional Doppler ultrasound enables the assessment of vascular blood flow indices in the gestational assessment, as well as allows for hemodynamic characterization by determining vascular resistance values, such as the resistivity index (RI) and pulsatility index (PI), obtained by measuring the peak systolic velocity (PSV) and the end-diastolic velocity (EDV). The study aims to assume hemodynamically normal values of the umbilical artery (umbilical cord-UC), uteroplacental artery, middle cerebral artery (MCA) and carotid artery of fetuses, of bitches in the final third of pregnancy, as well as correlating them with each other to predict indirectly the fetal viability and probable date of delivery. Thirty female dogs in the final third of pregnancy (40 - 60 days), clinically healthy, were evaluated. These patients were submitted to Doppler velocimetric ultrasonographic evaluation in two periods, the first, between 40-50 days and the second, between 51-60 days of gestation. In each phase, the indices of pulsatility and resistivity of the UC, uteroplacental artery, MCA and common carotid artery of the fetuses were analyzed. All data obtained were submitted to analysis of variance and the Tukey test, using a P value of 5%. Systolic velocities peak (SVP) and end-diastolic velocity (EDV) showed a progressive increase over the study period. Consequently, the S/D ratio decreased between the periods studied. The analysis of the umbilical cord resistivity (RI) and pulsatility (PI) indices showed an decrease from period 1 to period 2. Similarly, in the uteroplacentalal artery, the PSV and EDV values showed an increase between times, while the S/D ratio decreased. For the MCA and internal carotid artery, the PSV and VDF values increased until the end of pregnancy. The analysis of the cerebroplacental relationship (MCA/UA) showed decreasing values between periods P1 and P2, demonstrating a statistically significant difference (P < 0.05). The vascular flow velocities of the uteroplacental artery, UC, MCA and internal carotid artery showed values similar to those previously described in the literature for female dogs in the normal course of pregnancy. The data obtained in this study can be useful in identifying fetal centralization, contributing to the characterization of fetal viability, providing valuable data for a more effective scheduling of cesarean delivery, increasing the survival of newborns.

AVALIAÇÃO HEMODINÂMICA DE VASOS MATERNOFETAIS POR MEIO DE ANÁLISE ULTRASSONOGRÁFICA DOPPLERVELOCIMÉTRICA EM FETOS CANINOS SOB ESTRESSE, DURANTE O TERÇO FINAL DE GESTAÇÃO

A ultrassonografia gestacional pré-natal em cadelas é uma ferramenta diagnóstica para análise da viabilidade fetal. Por meio das técnicas de Doppler é possível a realização de uma avaliação obstétrica mais precisa, visto a capacidade de uma análise hemodinâmica e funcional em diversos vasos fetais. Os resultados desta Dissertação foram organizados em um capítulo, intitulado: Estruturas Maternofetais no Terço Final de Gestação em Cadelas com Fetos Sob Estresse, redigido conforme as normas do periódico Acta Scientia Veterinariae. Objetivou-se avaliar o comportamento hemodinâmico, por meio de ultrassonografia Doppler, do cordão umbilical (CU), artéria cerebral média (ACM) e artéria carótida comum (ACC), para caracterizar a resistência destes vasos maternofetais durante o terço final da gestação de cadelas com fetos em estresse, bem como correlaciona-los entre si e com o sofrimento fetal. Foram examinadas 30 cadelas saudáveis, sendo os vasos avaliados em dois tempos: (1º): 50-54 dias e (2º): 55-60 dias de gestação. As variáveis estudadas foram: velocidade de pico sistólico (VPS), velocidade diastólica final (VDF) e os índices de resistividade (IR) e de pulsatilidade (IP), bem como a relação sístole/diástole (S/D). A análise do IR e IP do CU demonstrou diminuição significativa dos valores médios do primeiro para o segundo tempo. Para as ACM e ACC, o IP, o IR e a relação S/D, demonstraram diferença estatística significativa entre os valores médios encontrados para os tempos estudados, no entanto, diminuindo do tempo 1 para o 2. A avaliação ultrassonográfica temporal por análise dopplervelocimétrica dos fluxos do CU, da ACM e da ACC permitiu a determinação de suas características e comportamento durante o tempo estudado, bem como a correlação entre os mesmos. Apesar de não ter sido acompanhado o desfecho da gestação, conclui-se que a utilização desta ferramenta mostrou-se segura para gestantes e fetos, bem como de obtenção relativamente fácil e rápida, podendo os resultados deste trabalho serem utilizados como base para pesquisas futuras. Ainda, por meio deste, é possível uma avaliação mais precisa de índices que indiquem sofrimento fetal.

Prenatal gestational ultrasound in bitches is a diagnostic tool for analyzing fetal viability. Through Doppler techniques, it is possible to carry out a more accurate obstetric evaluation, given the capacity of a hemodynamic and functional analysis in several fetal vessels. The results of this Dissertation were organized in a chapter entitled: Maternal-fetal Structures in the Final Third of Pregnancy in Bitches with Fetuses Under Stress, written according to the norms of the journal Acta Scientia Veterinariaes. The aim of this study was to evaluate the hemodynamic behavior by means of Doppler ultrasonography, of the umbilical cord (UC), middle cerebral artery (MCA) and common carotid artery (CCA), to characterize the resistance of these maternal-fetal vessels during the final third of pregnancy in bitches with fetuses in stress, as well as correlating them with each other and with fetal distress. Thirty healthy bitches were examined, and the vessels were evaluated in two stages: (1st): 50-54 days and (2nd): 55-60 days of gestation. The variables studied were: peak systolic velocity (PSV), end diastolic velocity (EDV) and resistivity (RI) and pulsatility (PI) indices, as well as the systole/diastole ratio (S/D). The analysis of the RI and PI of the UC showed a significant decrease in the mean values from the first to the second time. For MCA and CCA, PI, RI and S/D ratio showed a statistically significant difference between the mean values found for the times studied, however, decreasing from time 1 to 2. Temporal ultrasound evaluation by dopplervelocimetric analysis of the UC, MCA and the CCA flows allowed the determination of their characteristics and behavior during the studied time, as well as the correlation among them. Although the pregnancy outcome was not monitored, it is concluded that the use of this tool proved to be safe for pregnants and fetuses, as well as being relatively easy and quick to obtain, and the results of this work can be used as a basis for future research. Also, through this, a more accurate assessment of indices that indicate fetal distress is possible.

Systematization, distribution and territory of the middle cerebral artery and cerebroethmoidal artery on the brain's surface of the turkey (Meleagris gallopavo) / Sistematização, distribuição e território da artéria cerebral média e cerebroetmoidal na superfície do encéfalo em peru (Meleagris gallopavo)

Background: The cerebral arteries constitute the main blood transportation via to the brain and play a fundamental role in the maintenance of normal cerebral activities. There are a few studies about the encephalic irrigation in the wild and exotic species. This study aims to describe and systematize the middle cerebral artery and cerebroethmoidal artery of Meleagris gallopavo, to determine a standard model and territorial area of irrigation, and the main variations in this species.Materials, Methods & Results: For this research, 30 brain with the cervical spinal cord segment of 10 male and 20 female young and adult turkeys (Meleagris gallopavo) were used. Discarded animals were provided from Doux Frangosul breeding center, located in Caxias do Sul city, State of Rio Grande do Sul, Brazil, 2006. Animals were euthanized with T 61, with an intravenous injection. After the removal of the skin, the sternum was removed, the common carotid arteries were cannulated through the brachycephalic trunks. The arterial system of the 30 animals were rinsed with saline solution with heparin and filled with latex colored in red. Animals remained immersed for one hour in running water, and next, the neck was sectioned. Next, a bone window was opened in the skullcap. Pieces were fixed in 20% formaldehyde for seven days, and after this period, the brain was removed from the cranial vault...(AU)

Systematization, distribution and territory of the middle cerebral artery and cerebroethmoidal artery on the brain's surface of the turkey (Meleagris gallopavo) / Sistematização, distribuição e território da artéria cerebral média e cerebroetmoidal na superfície do encéfalo em peru (Meleagris gallopavo)

Background: The cerebral arteries constitute the main blood transportation via to the brain and play a fundamental role in the maintenance of normal cerebral activities. There are a few studies about the encephalic irrigation in the wild and exotic species. This study aims to describe and systematize the middle cerebral artery and cerebroethmoidal artery of Meleagris gallopavo, to determine a standard model and territorial area of irrigation, and the main variations in this species.Materials, Methods & Results: For this research, 30 brain with the cervical spinal cord segment of 10 male and 20 female young and adult turkeys (Meleagris gallopavo) were used. Discarded animals were provided from Doux Frangosul breeding center, located in Caxias do Sul city, State of Rio Grande do Sul, Brazil, 2006. Animals were euthanized with T 61, with an intravenous injection. After the removal of the skin, the sternum was removed, the common carotid arteries were cannulated through the brachycephalic trunks. The arterial system of the 30 animals were rinsed with saline solution with heparin and filled with latex colored in red. Animals remained immersed for one hour in running water, and next, the neck was sectioned. Next, a bone window was opened in the skullcap. Pieces were fixed in 20% formaldehyde for seven days, and after this period, the brain was removed from the cranial vault...

Systematization, distribution and territory of the caudal cerebral artery on the brain's surface of the turkey (Meleagris gallopavo) / Sistematização, distribuição e território da artéria cerebral caudal na superfície do encéfalo em peru (Meleagris gallopavo)

Thirty Meleagris gallopavo heads with their neck segments were used. Animals were contained and euthanized with the association of mebezonium iodide, embutramide and tetracaine hydrochloride (T 61, Intervet ) by intravenous injection. The arterial system was rinsed with cold saline solution (15°C), with 5000IU heparin and filled with red-colored latex. The samples were fixed in 20% formaldehyde for seven days. The brains were removed with a segment of cervical spinal cord and after, the dura-mater was removed and the arteries dissected. The cerebral carotid arteries, after the intercarotid anastomosis, were projected around the hypophysis, until they reached the tuber cinereum and divided into their terminal branches, the caudal branch and the rostral branch. The rostral branch was projected rostrolateralwards and gave off, in sequence, two collateral branches, the caudal cerebral and the middle cerebral arteries and the terminal branch was as cerebroethmoidal artery. The caudal cerebral artery of one antimere formed the interhemispheric artery, which gave off dorsal hemispheric branches to the convex surface of both antimeres. Its dorsal tectal mesencephalic branch, of only one antimere, originated the dorsal cerebellar artery. In the interior of the cerebral transverse fissure, after the origin of the dorsal tectal mesencephalic artery, the caudal cerebral artery emitted occipital hemispheric branches, pineal branches and medial hemispheric branches, on both antimeres. The caudal cerebral artery's territory comprehended the entire surface of the dorsal hemioptic lobe, the rostral surface of the cerebellum, the diencephalic structures, the caudal pole and the medial surface of the cerebral hemisphere and in the convex surface, the sagittal eminence except for its most rostral third. Due to the asymmetry found in the caudal cerebral arteries' ramifications, the models were classified into three types and their respective subtypes.(AU)

Foram utilizadas 30 cabeças com o segmento de pescoço deMeleagris gallopavo. Os animais foram contidos e eutanasiados com a associação de iodeto de mebezônio, embutramida e cloridrato de tetracaína (T 61 Intervet ), via endovenosa. O sistema arterial foi lavado com solução salina resfriada (15°C), com 5000UI heparina e preenchido com látex corado em vermelho. As peças foram fixadas em formaldeído a 20% por sete dias. O encéfalo foi removido com um segmento de medula espinhal, a dura-máter removida e as artérias dissecadas. As artérias carótidas do cérebro, após a anastomose intercarótica, projetaram-se contornando a hipófise até alcançarem o túber cinéreo e dividiram-se em seus ramos terminais, o ramo caudal e o ramo rostral. O ramo rostral projetou-se rostro-lateralmente emitindo em sequência seus dois principais ramos colaterais, as artérias cerebral caudal e cerebral média terminado-se como artéria cerebroetmoidal. A artéria cerebral caudal de um antímero formava a artéria inter-hemisférica que lançava ramos hemisféricos dosais para a face convexa de ambos os antímeros. Seu ramo tectal mesencefálico dorsal de apenas um antímero originava a artéria cerebelar dorsal. No interior da fissura transversa do cérebro após a origem da artéria tectal mesencefálica dorsal artéria cerebral caudal lançou ramos hemisféricos occipitais, ramos pineais e hemisféricos mediais em ambos os antímeros. O território da artéria cerebral caudal compreendeu toda a superfície do hemi lobo óptico dorsal, a face rostral do cerebelo, as estruturas diencefálicas, o polo caudal e a face medial do hemisfério cerebral e na face convexa do hemisfério cerebral a eminência sagital exceto seu terço mais rostral. Devido à assimetria encontrada nas ramificações das artérias cerebrais caudais, foram classificados os modelos em três tipos com seus respectivos subtipos.(AU)

Morfometria do encéfalo e formação do circuito arterial em equinos mestiços / Morphometry of the brain and arterial circuit formation in crossbread horse

The aim of this study was to describe the main branches of the basilar artery, formation of the arterial circuit and the morphometry of the brain in adult crossbreed horses of both sexes. The setting was made by plastic tube inserted into the common carotid artery with 10% formaldehyde solution. After fixed, latex solution stained with pigment was injected. Craniotomy, morphometry of the brain and dissection were made to identify the main branches of the basilar arteries and the formation of the arterial circuit. The mean and standard error of the mean of the basilar artery was 3.629 cm ± 0.1550 in males and 4.423 cm ± 0.1990 in females (p=0.0037). In all animals the basilar artery originated from the fusion of the vertebral arteries giving rise to caudal cerebellar arteries, different numbers of branches to bulbus and pons, terminal branches and rostral cerebellar arteries. The arteries of the base of the brain depended on the carotid and vertebral-basilar systems. The brain circuit was closed rostrally and caudally in all horses.

O objetivo desta investigação foi caracterizar a morfometria do encéfalo e a formação do circuito arterial em equinos adultos mestiços de ambos os sexos. A fixação foi feita através de cânula plástica introduzida na artéria carótida comum com solução de formaldeído a 10%.  Em seguida, foram feitas repleções vasculares com solução aquosa de Petrolátex S65 corado com pigmento Suvinil vermelho. Procedeu-se a craniotomia, remoção e morfometria dos encéfalos e dissecção para a observação das ramificações principais da artéria basilar e formação do circuito arterial. A média mais erro padrão da média do comprimento da artéria basilar foi de 3,629 cm ± 0,1550 nos machos e 4,423 cm ± 0,1990 nas fêmeas (p=0,0037). Em todos os equinos dissecados, a artéria basilar originou-se da convergência das artérias vertebrais, emitindo a artéria cerebelar caudal, ramos variados para bulbo e ponte, ramos terminais e artérias cerebelares rostrais. As artérias da base do encéfalo estiveram na dependência dos sistemas carótico e vértebrobasilar. O circuito arterial do cérebro apresentou-se fechado rostral e caudalmente em 100% dos animais dissecados.