树鼩(Tupaia belangeri chinensis)的脑底动脉环

THE WILLIS CIRCLE IN TUPAIA BELANGERI CHINENSIS

用25只树鼩,从升主动脉灌注带色的橡胶乳液,在解剖显微镜下进行解剖观察,用目测微尺进行测量。大多数树鼩(22只)有完整的脑底动脉环。由左、右大脑前动脉向内侧各发一前交通动脉组成大脑前总动脉。前交通动脉口径为大脑前动脉的75～85％。后交通动脉口径与大脑后动脉相近,连于颈内动脉与大脑后动脉(基底动脉的分支)之间。测量了组成脑底动脉环有关动脉的口径。由于后交通动脉足够粗大,只有中断左、右颈总动脉和左、右椎动脉,才能造成全脑缺血。

The Willis' Circles in 25 tree shrews were studied. Latex mixed with China ink was injected into the ascending aorta of all animls. Under the anatomical microscope, the main branches of the Circles were observed and measured. There is a complete Willis' Circle in most of the animals (88%). The anterior cerebral artery of each side sends off a median branch, and both branches form a common anterior cerebral artery. These two branches may be called anterior communicating arteries. In addition, right and left posterior communicating arteries communicate internal carotid arteries and posterior cerebral arteries which come from basilar artery. The calibre of anterior and posterior communicating arteries are sufficiently enough, therefore if one wants to make a whole cerebral ischemia of tree shrew one has to ligate all the four arteries, i. e., the right and left common carotid and vertebral arteries.