Human anatomy, including structure and development and practical considerations . cleus as a centre for inipillary reflexes (Hernheimer) has been seriouslyshaken by the recent observations of Tsuchida. This investigator also denies the existenceof a well marked and constant unpaired median nucleus as described by Perlia, but admits thepresence of broken groups of medially placed cells, especially in the upper and lower thirds othe nucleus. The lateral group of cells, beginning in the floor of the third ventricle and extend-ing cautlally as far as the upper third of the chief nucleus, constitut
Human anatomy, including structure and development and practical considerations . cleus as a centre for inipillary reflexes (Hernheimer) has been seriouslyshaken by the recent observations of Tsuchida. This investigator also denies the existenceof a well marked and constant unpaired median nucleus as described by Perlia, but admits thepresence of broken groups of medially placed cells, especially in the upper and lower thirds othe nucleus. The lateral group of cells, beginning in the floor of the third ventricle and extend-ing cautlally as far as the upper third of the chief nucleus, constitutes the nucleus of Darksche-witsch. Notwithstanding its proximity to the origin of the third nerve, tiiis nucleus is nowregarded as having no direct relation with tiiat of the oculomotor, but as standing in intimate asso-ciation with the posterior longitudinal bundle, among whose fibres the cells to a large extentlie; it is, therefore, now often referred to as the nucleus fasciculi longitudinalis posterioris. Fig. 1051. I e u .2 S 3 0 ; 0. e: -?3 0 & ^ \ \ \ \ Jg -75 ^ -3. ; Lachrymal--gland __ Levator palpe-briL- superiorisSuperiorrectus muscle .External rectus,insertion Inferior oblique~ muscle Cut surface of malar bone Dissection of right orbit, showing oculomotor and abducent nerves. Although it may be assumed witii much probability that the fibres destined for the differenteye-muscles originate from definite groups of nerve-cells, all attempts to locate with accuracythe position of such centres within the ocuh^motor nucleus have met with only partial conclusions, based upon histological, einbryological. comparative and clinical data,point to an unexpected diffuseness in the origin of the oculomotor fibres willi only a limitedrelation to distinct groups. Concerning the mooted question as to the extent of of the oculomotor fibresit seems probable that such crossing occurs principally within the caudal portion of thechief nuclei, although, accord
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Keywords: ., bookauthormc, bookcentury1900, bookdecade1910, booksubjectanatomy
