MICROSURGICAL ANATOMY OF THE ARTERIES OF BRAIN STEM——THE ARTERIES OF MESENCEPHALON AND MEDULLA OBLONGATA / 解剖学报

ABSTRACT

The continuous artery-vein infusion method was used for the study of the origin, number, course, anastomosis, point of penetration and distribution of external arteries on 60 sides and internal arteries on 18 sides of the brain stem (mesencepha- lon and medulla oblongata) in Chinese under magnifiers (10-16?). The arteries of the brain stem can be divided into four groups the anteromedial, anterolateral, lateral and posterior arteries. Each group originates from several different arteries. The spot where external arteries penetrate into the substance of brain stem is called the point of penetration, several points of penetration concentrating together make the dense penetrating area. The dense penetrating areas on mesencephalon are the interpeduncular fossa and sulcus lateralis and those on the medulla oblongata are the fissurae mediana anterior and sulcus posterior to olive. There are fine arterial networks in the pia mater of the brain stem. In the mesencephalon and the closed portion of the medulla oblongata, the internal arteries traverse centripetally while in the open portion of the medulla oblongata, they course towards the floor of the fourth ventricle. The calibre of arteries in each group decreases anteroposteriorly. A comparatively constant blood supply area is available to each group.