66 



PRACTICAL ANATOMY. 



The suprascapular to the shoulder. 



The inferior tliyroid to the thyroid gland. 



The transi'crsalis colli. 



1. The internal mammary (Fig. 36) is given off from the under part of 

 the first stage of the subclavian artery. Its course, branches, anastomoses, and 

 important relations are in the anterior thoracic walls, where you will find its 

 description when you dissect that part. 



2. The suprascapular artery (Fig. 37) is attended by a vein and nerve of 

 the same name. It crosses the trunks of the brachial plexus, and is distributed 

 to the supra- and infraspinati muscles. 



3. The Inferior Thyroid Artery. Trace this artery behind the common 

 carotid artery and sympathetic nerve. Very often the middle cervical ganglion 

 of the sympathetic nerve rests on the inferior thyroid artery. Usually the artery 



Scalenue medius 



Scaleaua anticus and 



on it phrenic nerve 



Transverse cerricat 



artery 



Suprmca[nrfar artery 



Sttbclavian artery 



CORD OF BRA CHI A 1, 

 PLEXUS, GIVING 

 OFF MUHCULO- 

 CUTANEOUS AND 

 OUTER HEAD OF 

 MEDIAN NERVES 



Axillary artery 



MUSCULO-SPIRAL - 

 NER VE 



Thyroid art's 



Internal jugular vein 



Right common carotid 



artery 



r.\EI'M<ll-iASTRIC 

 NERVE 



. Commencement of 



t\ innominate vein 



and tu-o circun'jles arteries 



FIG. 37. THE SUBCLAVIAN VKSSKI.S. 

 (From a dissection in the Hunterian Museum.) 



lies in front of the recurrent laryngeal nerve ; sometimes you will find the reverse 

 is true. In operations on the thyroid gland isolate (i) the recurrent laryngeal 

 nerve, (2) the sympathetic. 



The branches of the inferior thyroid artery : 



1. The inferior laryngeal to the larynx. 



2. TracJieal branches to the trachea. 



3. CEsophageal branches to the oesophagus. 



4. Branches to the depressor muscles of the hyoid bone. 



5. Ascending cervical branches to the muscles of the neck. 



The Superior Intercostal Artery (Fig. 39). This is given off from the 

 second stage of the subclavian artery. It gives off a communicating branch to 

 the first aortic intercostal, which you will find high in the thorax, when you 



