. Cunningham's Text-book of anatomy. Anatomy. THE MOEPHOLOGY OF THE CEEEBEAL NEEVES. 797 and arch. The lingual branches are regarded as the main stem (post-trematic), the pharyngeal branches as subordinate branches ; the tympanic branch being the- prse-branchial or prae-trematic branch for the anterior margin of the third gill-cleft. The vagus nerve is generally regarded as representing the fusion of all the branchial nerves behind the glossopharyngeal. Its efferent fibres are in series with those of the glossopharyngeal above and the accessory nerve below, and belong to the lateral series of
. Cunningham's Text-book of anatomy. Anatomy. THE MOEPHOLOGY OF THE CEEEBEAL NEEVES. 797 and arch. The lingual branches are regarded as the main stem (post-trematic), the pharyngeal branches as subordinate branches ; the tympanic branch being the- prse-branchial or prae-trematic branch for the anterior margin of the third gill-cleft. The vagus nerve is generally regarded as representing the fusion of all the branchial nerves behind the glossopharyngeal. Its efferent fibres are in series with those of the glossopharyngeal above and the accessory nerve below, and belong to the lateral series of His. Its afferent fibres, like those of the glossopharyngeal, represent two elements. The ganglion nodosum has possible connexions with epibranchial sense-organs—the rest of the nerve representing the fused branchial nerves of fishes. The superior laryngeal nerve is looked upon as the branchial nerve of the fourth, and the recurrent nerve as the branchial nerve of the fifth arch. While the relation of the nerve to the hinder gill-arches and clefts makes it possible to understand the innervation by the vagus of the heart and lungs, no satisfactory explanation is forthcoming of the passage of the nerve into the abdomen, and its distribution to the stomach and other organs below the Fig. 666.—Scheme to illustrate the Disposition of the Myotomes in the Embryo in relation to the Head, Trunk, and Limbs. A, B, C, First three cephalic myotomes; N, 1, 2, 3, 4, Last persisting cephalic myotomes ; C, T, L, S, Co, The myotomes of the cervical, thoracic, lumbar, sacral, and caudal regions ; I., II., III., IV., V., VI., VII., VIIL, IX., X., XL, XII., refer to the cerebral nerves, and the structures with which they may be embryologically associated. The accessory nerve consists of two parts. The internal ramus (accessory portion) of the nerve consists of efferent fibres for the branchial region, in series with the lateral motor roots of the glossopharyngeal and vagus nerves- T
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1914
