Human anatomy, including structure and development and practical considerations . c\^ pineal stalk,cur\es forward to be-come continuous withthe stria , its base is unitedwith the posterior com-missure of the brainoverlying the entranceinto the Sylvian aque-duct. Between thehabenular and posterior commissures a small pointed diverticulum, ih^ pineal reeess,extends from the third ventricle for a \ery short distance into the pineal body,and thus recalls the early condition in which the organ is developed as a tubularoutgrowth in the roof-plate of the diencephalon. This relation to
Human anatomy, including structure and development and practical considerations . c\^ pineal stalk,cur\es forward to be-come continuous withthe stria , its base is unitedwith the posterior com-missure of the brainoverlying the entranceinto the Sylvian aque-duct. Between thehabenular and posterior commissures a small pointed diverticulum, ih^ pineal reeess,extends from the third ventricle for a \ery short distance into the pineal body,and thus recalls the early condition in which the organ is developed as a tubularoutgrowth in the roof-plate of the diencephalon. This relation to the thin ventricularroof the body retains, its apex later becoming closely surrounded by and embeddedwithin the loose vascular tissue of the pia mater. The structure of the pineal body, as seen in cross-section (Fig. 971), includesa reticular framework of connective tissue trabeculae, whose meshes are filled with. tissue septa *jlrp», /â¢â¢ilM â . Jj-}â â â °:\I\i-^* //a*Section of pineal body showing calcareous concretions or brain-sand, v 150. TiiK i)ii:xci:pn.\ I 12 = 972. area \Kcliiial area ^ rounded or sometimes elongated epithelial iclls, which often contain brownish ^-ment. With the e.\ee|)tion of a few nerve-filaments in the antericjr part, ])njbablvsympathetic in origin and destined for the blood-\essels, and a dense net-work ofneurojj;lia fibres in the under part, the pineal body contains no ele- ^⢠ments of a nervous character, nerve-cells being absent. Quite com-monly the adult organ encloses avariable number of concretions,often ca.\\(ic\/>ra///-sa/id{ accrvulus ),which consist of laminated ])articlescomposed of calcium carbonateand phosphate mingled with or-ganic material. They may be ofmicroscopic dimensions, or reachthe size of a millet seed, and byaggregation assume a mammillatedform. iUootl-vessel Diverticuhini (lividiiiK into tubules V- â
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Keywords: ., bookauthormc, bookcentury1900, bookdecade1910, booksubjectanatomy
