136 APPLIED ANATOMY. 



below the hyoid bone. Instead of two anterior jugular veins there may be one; in 

 this case it is likely to go down the median line of the neck and so be wounded in 

 tracheotomy. It receives branches from the inferior thyroid veins and hence may 

 bleed freely. It has no valves. 



The internal jugular vein lies to the outer side of and bulges somewhat an- 

 terior to the carotid arteries. It is formed by the junction of the inferior petrosal 

 and lateral sinuses at the jugular foramen, and passes downward posterior to the 

 internal carotid artery and soon reaches its outer side. It receives the facial, lingual, 

 pharyngeal, superior and middle thyroid, and sometimes the occipital veins. A large 

 communicating branch from the external jugular unites either with the facial or with 

 the internal jugular, so that a wound of the external jugular may draw blood directly 

 from the internal jugular. 



These tributary veins are superficial to the arteries and in ligating the external 

 carotid artery they will have to be displaced. The internal jugular vein is sometimes 



Hyoglossus muscle 



Hypoglossal nerve 



Descendens hypoglossi nerve 



Superior laryngeal nerve 



Omohyoid muscle 



Sternohyoid muscle 

 Sternothyroid muscle 

 Superior thyroid vein 



Omohyoid muscl 

 Middle thyroid vein 



Inf. thyroid artery 



Recurrent laryngeal 



nerve 



Sternothyroid 

 and hyoid 

 muscles 

 Inferior thy- 

 roid (thyroid- 

 ea ima) vein 



Space of Burns 



-Digastric muscle 

 Mylohyoid muscle 

 Facial artery 

 jf_^ -Facial vein 



Submaxillary gland 

 Hyoid bone 

 Lingual artery 



Internal jugular vein 

 Superior thyroid artery 

 Omohyoid muscle 

 Sternohyoid muscle 

 Anterior jugular vein 



Cricoid cartilage 

 Sternothyroid muscle 

 Sternomastoid 



itr 



FIG. 168. Dissection of the deep structures of the front of the neck. 



excised in -operations for enlarged lymph-nodes or for infective thrombus. It is not 

 so large above the facial vein as below that point. It becomes so involved in enlarge- 

 ments of both tuberculous and carcinomatous lymph-nodes that it may be neces- 

 sary to excise it along with the tumor. Its removal does not give rise- to any serious 

 symptoms. 



It becomes thrombosed by the extension of a thrombus from the transverse 

 (lateral) sinus, which in turn becomes affected by the extension of suppurative 

 middle-ear disease through the medium of caries of the bones. When the internal 

 jugular is thrombosed it is evidenced by swelling, redness, and tenderness along 

 the anterior border of the sternomastoid muscle just behind the angle of the jaw. 

 Bleeding from the veins in this region is particularly dangerous because the internal 

 jugular itself is so large and having no valves, will bleed both from the side towards 

 the heart and that towards the head. 



The veins also, which are tributary to it in this region, are so large and are 

 wounded so close to the main trunk that the blood from the internal jugular itself 



