Henry Gray (18251861). Anatomy of the Human Body. 1918.
of each peduncle is crossed from the medial to the lateral side by the superior cerebellar and posterior cerebral arteries; its lateral surface is in relation to the gyrus hippocampi of the cerebral hemisphere and is crossed from behind forward by the trochlear nerve. Close to the point of disappearance of the peduncle into the cerebral hemisphere, the optic tract winds forward around its ventro-lateral surface. The medial surface of the peduncle forms the lateral boundary of the interpeduncular fossa, and is marked by a longitudinal furrow, the oculomotor sulcus, from which the roots of the oculomotor nerve emerge. On the lateral surface of each peduncle there is a second longitudinal furrow, termed the lateral sulcus; the fibers of the lateral lemniscus come to the surface in this sulcus, and pass backward and upward, to disappear under the inferior colliculus.
FIG. 711 Transverse section of mid-brain at level of inferior colliculi. (See enlarged image)
FIG. 712 Transverse section of mid-brain at level of superior colliculi. (See enlarged image)
Structure of the Cerebral Peduncles (Figs. 711,712).On transverse section, each peduncle is seen to consist of a dorsal and a ventral part, separated by a deeply pigmented lamina of gray substance, termed the substantia nigra. The dorsal part