THE CRANIAL NERVES 



87 



vertebral column through the intervertebral foramina — and the 

 cranial or cerebral nerves — those arising from the brain and passing 

 through the foramina of the skull — in addition to the autonomic 

 system, described on page 74. Of these the spinal nerves (p. 73) 

 are less modified, in both structure and distribution. 



N.-^ .--'^^--Y'-^ 



/ v:- i 



Fig. 46. Dissection from the ventral surface of the neck. On the right 

 side the platysma and depressor conchae posterior are reflected with the skin. 

 The vagus nerve is in proper relation to the external jugular vein and the 

 common carotid artery. On the left side the external jugular vein, parotid 

 and submaxillary glands, and the sternohyoid. sternomastoid._ and cleido- 

 mastoid muscles are removed, the common carotid displaced medially and the 

 nerves laterally, but otherwise in proper relation. 



be, basioclavicularis: cc, common carotid artery; cm. cleidomastoideus; 

 c3, c4._ c5, cervical spinal nerves; d, digastricus; fa, anterior facial vein; fp, 

 posterior facial vein; gcs, superior cervical ganglion; gn, ganglion nodosum; 

 gp, parotid gland; gs, submaxillary gland; gt, thyreoid^ gland; Icp. deep 

 cervical lymph gland; m, masseter; my, mylohyoideus; pi, medial insertion 

 portion of masseter concealing the pterygoideus internus; pi, platysma; rev, 

 cardiac branch of vagus nerve (n. depressor) ; rdh, descending branch of 

 hypoglossal nerve; s, stylohyoideus major; sh, sternohyoideus; sm_, sterno- 

 mastoideus; st. sternothyreoideus; t, thyreohyoideus ; ts, sympathetic trunk; 

 vje. external jugular vein; vji, internal jugular vein; X, vagus nerve; 

 XII. hypoglossal nerve. (From dissection by W. H. T. Baillie, drawing by 

 E. B. Logier.) 



