双峰驼的大脑动脉环和椎基底动脉

THE CEREBRAL ARTERIAL CIRCLE AND VERTEBRAL-BASILAR ARTERY OF CAMEL(Bactrianus Camelus)

By means of the introarterial-injected preparations with oil dye(in some cases with neuprene latex),the cerebral arterial circle and vertebral-basilar artery of camel (Bactrianus Camelus)were studied in 15 cases.The results obtained are as follows: 1.The cerebral arterial circle is composed of two parts,and is formed by the internal carotid artery intracranial segments and the caudal communicating arteries as well as their branches of both sides,respectively.66.7 per cent of the caudal communicating arteries originate from the carotid rete,33.3 per cent from the inter- nal carotid artery intracranial segment.Anastomosis was found between these two vessels in 46.7 per cent and 20.0 per cent has no communicating branches.This is different from other mammals.The average diameters of the two vessels are 0.216+ 0.057 cm and 0.178+0.056 cm,respectively.The circle gives the following vessels: rostral cerebral arteries,middle cerebral arteries,caudal cerebral arteries,and the caudal segment of basilar artery. 2.After receiving the branches of occipital artery,the vertebral artery enters into the cranial cavity and divides to form the cerebral-spinal circle together with branches on the opposite side.The circle gives rise to the caudal segment of basilar artery and ventral spinal artery. 3.The course of the basilar artery differs in no way from the usual pattern found in other mammals,but it is of interest to note that the calibre of this vessel indicate the flow of the blood away the cerebral arterial circle as well as the cere- bral-spinal circle.The vessels arisen from the basilar artery are rostrol cerebellar arteries,caudal cerebellar arteries,postpone branches and medullary branches.