The development of the human body; a manual of human embryology . B tig. iou.—pwuk ue uk Pharynx of Embryos of (A) 7 and (B) 10 MM. SHOWING THE DEVELOPMENT OF THE TONGUE. Ep, Epiglottis; Sp, precervical sinus; tl and t2, median and lateral portions of the tongue; / to IV, branchial arches.—(His.) inent and rounded upon its oral surface, and forms theanterior portion of the tongue (Fig. 160, B, t1). Thismedian elevation is bounded at the sides and almost tothe median line in front by the alveolo-lingual grooves,and posteriorly it is separated from the anterior edge ofthe second branchial arch b
The development of the human body; a manual of human embryology . B tig. iou.—pwuk ue uk Pharynx of Embryos of (A) 7 and (B) 10 MM. SHOWING THE DEVELOPMENT OF THE TONGUE. Ep, Epiglottis; Sp, precervical sinus; tl and t2, median and lateral portions of the tongue; / to IV, branchial arches.—(His.) inent and rounded upon its oral surface, and forms theanterior portion of the tongue (Fig. 160, B, t1). Thismedian elevation is bounded at the sides and almost tothe median line in front by the alveolo-lingual grooves,and posteriorly it is separated from the anterior edge ofthe second branchial arch by a distinct V-shaped groove,at the apex of which is a deep circular depression, theforamen crncum (see p. 313). The posterior portion of the tongue arises as thickenings. THE TONGUE. 307 of the ventral ends of the second branchial arches, and isconsequently a V-shaped structure, into the angle of whichthe posterior part of the anterior portion of the tonguefits (Fig. 161). The two portions, anterior and posterior,eventually fuse together, but the groove which originallyseparated them remains more or less clearly distinguish-able, the circumvallate pa-pilla? (see p. 458) develop-ing immediately anteriorto it. The tongue is essentially amuscular organ, being formedof a central mass of musculartissue, enclosed at the sidesand dorsally by mucous mem-brane derived from the floorof the mouth and muscular tissue consistspartly of fibers limited to thesubstance of the tongue andforming the m. lingualis, andalso of a number of extrinsicmuscles, the hyoglossi, genio- hyoglossi, styloglossi, palatoglossi, and chondroglossi. The lasttwo muscles are innervated by the vagus nerve, and theremaining extrinsic muscles receive fibers from the hypo-glossal, w
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectembryol, bookyear1902
