. Quain's elements of anatomy . ther parts of the brain. They then form large hollowbodies with comparatively thin walls superiorly, the lateral ventricles beiag greatly Fig. 739. ^VlEW OP THE INNER Fig. 739. SURFACE OF THE RIGHT HALFOF THE FCETAL BRAIN OF ABOUT SIX MOUTHS. (From Eeichert.) F, frontal lobe ; P, parietal ;0, occipital; T, temporal ; I,olfactory bulb; II, right opticnerve; fp, calloso-marginal fis-sure ; p, external ; p, internalparts of the parieto-occipital fis-sure; h, ealcarine fissure ; g, gyrusfornicatus; c, c, corpus callosum ;s, septum lucidum; /, placedbetween the middl
. Quain's elements of anatomy . ther parts of the brain. They then form large hollowbodies with comparatively thin walls superiorly, the lateral ventricles beiag greatly Fig. 739. ^VlEW OP THE INNER Fig. 739. SURFACE OF THE RIGHT HALFOF THE FCETAL BRAIN OF ABOUT SIX MOUTHS. (From Eeichert.) F, frontal lobe ; P, parietal ;0, occipital; T, temporal ; I,olfactory bulb; II, right opticnerve; fp, calloso-marginal fis-sure ; p, external ; p, internalparts of the parieto-occipital fis-sure; h, ealcarine fissure ; g, gyrusfornicatus; c, c, corpus callosum ;s, septum lucidum; /, placedbetween the middle commissureand the foramen of Monro;V, in the upper part of thethird ventricle immediately be-low the velum interpositum andfornix ; v, in the back part of the third ventricle below the pineal gland, and pointing by a line to the aqueduct ofSylvius ; v, in the lower part of the third ventricle above the infundibulum ; r, recessuspinealis passing backwards from the tela choroidea ; pv, pons Varolii; Ce, cerebellum. VOL. II. 3 H. 834 THE NERYOUS SYSTEM. dilated, and communicating by a wide aperture with, each other, and with, thethird ventricle, by the foramen of Monro. The growth of the hemispheres takesplace progressively from before backwards, so that they come to cover in succes-sion the thalami, corpora quadrigemina and cerebellum, which all originally stoodin a series behind them, as they do permanently iu the lowest vertebrates. Bythe end of the thii-d month the hemispheres have extended so far backwards asto cover the thalami; at the fourth they reach the corpora quadrigemina ; at thesixth they cover those bodies and great part of the cerebellum, beyond whichthey project still further ^backwards by the end of the seventh month. The floor especially of the hemispheres thickens considerably, and the corpusstriatum increasing greatly in magnitude, at the same time projects upwards intothe lateral ventricles so as to give these cavities an arched foi-m and mark outtheir ante
Size: 1847px × 1352px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookcentury1800, booksubjectanatomy, booksubjecthumananatomy
