Henry Gray (18251861). Anatomy of the Human Body. 1918.
chiasma, the tuber cinereum and infundibulum, and the corpora mammillaria. Behind the last, the floor is formed by the interpeduncular fossa and the tegmenta of the cerebral peduncles. The ventricle is prolonged downward as a funnel-shaped recess, the recessus infundibuli, into the infundibulum, and to the apex of the latter the hypophysis is attached.
The anterior boundary is constituted below by the lamina terminalis, a thin layer of gray substance stretching from the upper surface of the optic chiasma to the rostrum of the corpus callosum; above by the columns of the fornix and the anterior commissure. At the junction of the floor and anterior wall, immediately above the optic chiasma, the ventricle presents a small angular recess or diverticulum, the optic recess. Between the columns of the fornix, and above the anterior commissure, is a second recess termed the vulva. At the junction of the roof and anterior wall of the ventricle, and situated between the thalami behind and the columns of the fornix in front, is the interventricular foramen (foramen of Monro) through which the third communicates with the lateral ventricles.
FIG. 723 Coronal section of lateral and third ventricles. (Diagrammatic.) (See enlarged image)
The posterior boundary is constituted by the pineal body, the posterior commissure and the cerebral aqueduct. A small recess, the recessus pinealis, projects into the stalk of the pineal body, while in front of and above the pineal body is a second recess, the recessus suprapinealis, consisting of a diverticulum of the epithelium which forms the ventricular roof.
Each lateral wall consists of an upper portion formed by the medial surface of the anterior two-thirds of the thalamus, and a lower consisting of an upward continuation of the gray substance of the ventricular floor. These two parts correspond to the alar and basal laminæ respectively of the lateral wall of the fore-brain vesicle and are separated from each other by a furrow, the sulcus of Monro, which extends from the interventricular foramen to the cerebral aqueduct (pages 741 and 742). The lateral wall is limited above by the tænia thalami. The columns of the fornix curve downward in front of the interventricular foramen, and then run in the lateral walls of the ventricle, where, at first, they form distinct prominences, but subsequently are lost to sight. The lateral walls are joined to each other across the cavity of the ventricle by a band of gray matter, the massa intermedia (page 809).
Interpeduncular Fossa (Fig. 724).This is a somewhat lozenge-shaped area of the base of the brain, limited in front by the optic chiasma, behind by the antero-superior surface of the pons, antero-laterally by the converging optic tracts,