Willis氏环后部的显微解剖学

MICROANATOMY OF THE POSTERIOR PORTION OF CIRCLE OF WILLIS

在解剖显微镜下放大6~40倍,观察了125例成人和儿童脑Willis氏环后部的血管。颈内动脉末段两侧等粗者占47.20±4.46%,发出平均2.5条穿支,穿入前穿质、视束、灰结节和颞叶内侧面。脉络丛前动脉有99.20±0.56%发自颈内动脉,通常两次越视束,最后入脉络裂,分支至前穿质、颞叶、视束,丘脑下部视束沟、外侧膝状体和海马回钩。后交通动脉的形态可分平直、弯曲、襻状及后部呈丛状四型。弯曲型在成人多见,发出平均8.1条穿支,穿入灰结节、视束、丘脑下部视束沟、乳头体、大脑脚以及视束、大脑脚与乳头体之间的区域。根据后交通动脉管径变异,Willis氏环可分近代型、原始型、过渡型及混合型。两侧大脑后动脉近侧段等粗者占57.60±4.42%,发出平均3.1条后穿动脉,穿入乳头体、后穿质、大脑脚和脚间窝。此外,本文对四叠体动脉和乳头体的血液供应作了调查和讨论。

The posterior portion of the circle of Willis was examined in 125 adult and child brains under 6~40 magnification.The following results were obtained:The terminal segments of the two internal carotid arteries were mostly equal in size(47.20±4.46%).An average of 2.5 perforating branches commonly arose from this segment distal to the origin of the posterior communicating artery.They penetrated into the anterior perforating substance,optic tract,tuber cinerum and the medial surface of the temporal lobe.The anterior choroid artery was found to originate from the internal carotid artery in 99.20±0.56%of 250 hemispheres.It usually originated laterally to the optic tract,crossed it twice,and then entered into the choroid fissure.Along its course,it sent off branches penetrating into the anterior perforating substance,temporal lobe,optic tract,hypothalamus-tractus furrow,lateral geniculate body and the uncus.The configuration of the posterior communication artery could be grouped into 4 types:straight,curved,looped and plexiform of the posterior portion.The curved type was more common in adults.The PCOA gave rise to an average of 8.1 perforating branches which emerged into tuber cinerum,optic tract,hypothalamustractus opticus furrow,mammillary body,crus cerebri,and the region located between optic tract and crus cerebri laterally,and mammillary body medially.According to the variety of calibres of the PCOA,the Willis'circle could be classified into modern,primitive,transitional and mixed type.The calibre of proximal portion of the posterior cerebral artery was equal in size bilaterally in 57.60±4.4%.There was an average of 3.1 posterior perforating arteries arising from P_(1).They entered into the mammillary body,interpeduncular fossa,posterior perforating substance and crus cerebri.The collicular artery and the blood supply of mammillary body were observed and briefly discussed.