SHOULDER SCAPULAR REGION 61 



blood-vessels take part in this, viz. (a) the transverse artery 

 of the scapula; (6) ramus descendens of the transverse 

 cervical artery ; and (c) the subscapular artery. 



The ramus descendens of the transverse cervical artery (O.T. 

 posterior scapular) runs downwards in relation to the vertebral 

 border of the scapula, and dispenses branches upon both the 

 dorsal and costal aspects of the bone. The subscapular artery 

 runs downwards and medially along the axillary border of 

 the scapula, and at the inferior angle some of its terminal 

 branches anastomose with the terminal twigs of the ramus 

 descendens of the transverse cervical artery. The transverse 

 artery of the scapula is brought into communication with the 

 ramus descendens of the transverse cervical artery at the 

 upper margin, by an anastomosis in the neighbourhood of 

 the medial angle of the bone. 



But still more distinct anastomoses take place upon the 

 dorsal and costal aspects of the bone. In the supraspinous 

 fossa, branches of the transverse artery of the scapula inosculate 

 with twigs from the ramus descendens of the transverse cervical 

 artery ; whilst in the infraspinous fossa, free communications 

 are established between the circumflex artery of the scapula, 

 the transverse artery of the scapula, and the ramus descendens 

 of the transverse cervical artery. 



On the ventral aspect of the scapula, the ventral branch 

 of the transverse artery of the scapula, the ventral branches of 

 the circumflex artery of the scapula, and the ventral branches 

 of the ramus descendens of the transverse cervical artery join to 

 form a network. 



The importance of this free communication between the blood-vessels in 

 relation to the scapula will be manifest when it is remembered that two of 

 the main arteries, viz. the ramus descendens of the transverse cervical 

 artery and the transverse artery of the scapula spring indirectly from the 

 first part of the subclavian; whilst the third, viz. the subscapular, arises 

 from the third part of the axillary. When, therefore, a ligature is applied 

 to any part of the great arterial trunk of the upper limb, between the first 

 stage of the subclavian and the third part of the axillary, this anastomosis 

 affords ample means of re-establishing the circulation. 



Dissection. Detach the subscapularis from the scapula and lift it 

 laterally to its insertion. This will afford a better view of its relation to the 

 capsule of the shoulder-joint, and also of the subscapular bursa. In a 

 well-injected subject the ventral anastomosis can likewise be made out. 



Ligamentum Transversum Scapulae Superius (O.T. Supra- 

 scapular Ligament) and Lig. Trans versum Scapulae Inferius 

 (O.T. Spinoglenoid Ligament). These are two ligamentous 



