DISSECTION OF THE DOG 



147 



maxillary veins, the external jugular crosses the surface of the sterno- cephalic 

 muscle to assist the subclavian in the formation of the innominate vein. 



The following tributaries join the jugular at different points in its course : 

 (1) Small veins from the skin ; (2) a large and a small communicating branch 

 from the cephalic vein of the arm ; (3) the companion vein of the ascending 

 cervical artery ; (4) the companion vein of the transverse scapular artery. 



TO. splenitis 



m. biventer cervicis 



Plexus brachialis 



in. complexus 



i 

 i 



1 m. longissimus 

 / 



capitis 



n. accessorius — — ~" --„ 



m. omo-transversarius 



m. cIl i lo-mastoideus 



to. longissimus 

 I cervicis 



m. sterno-cephalicus- 



n. vagus cl truncus 

 sympathicus ~ 



a. carotis — 



o. jugularis interna 

 v. jugularis externa 

 mm. sterno-hynideus et ~ 



slcrno-thyreoideus 



a. axillaris 



ji. thoracalis longus 



m. serratus dorsalis 



m. pectoralis super/icialis 



m. transversus costarum 



m. scalenus 



m. serratus ventralis 



in. pectoralis profundus 

 m. obliquus abdominis exter 

 Fig. 55. — Dissection of the side of the neck and thorax. 



Very commonly the two last named unite to form an omo-cervical trunk 

 which, in its turn, joins the jugular. 



V. maxillahis externa. — The external maxillary vein drains the blood 

 from the face, the tongue, and the mandibular region. The main root is 

 formed by the common facial vein which will be found in the groove between 

 the masseter and digastric muscles. About the ventral border of the sub- 

 maxillary gland the facial vein receives the common trunk formed by the 

 union of the lingual and sublingual veins, and then changes its name to that of 

 external maxillary vein. 



l2 



