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Cortical. The cortical branches are the anterior temporal branches, to the basal 

 surface of the anterior portion of the temporal lobe; the posterior temporal branches, 

 to the external surface of the occipital lobe and the subtemporal convolution; 

 and the occipital branches, to the mesal and lateral surfaces of the occipital lobe. 



ARTERIES OF THE UPPER EXTREMITY. 



The artery which supplies the upper extremity continues as a single trunk 

 from its commencement down to the elbow, but different portions of it have 

 received different names according to the region through which it passes. That 

 part of the vessel which extends from its origin to the outer border of the first 

 rib is termed the subclavian artery; beyond this point to the lower border of the 

 axilla it is termed the axillary artery; and from the lower margin of the axillary 

 space to the bend of the elbow it is termed the brachial artery; here the single trunk 

 terminates by dividing into two branches, the radial and ulnar. 



THE SUBCLAVIAN ARTERY (A. SUBCLAVIA) (Fig. 456). 



On the right side the subclavian artery arises from the innominate artery opposite 

 the right sternoclavicular articulation; on the left side it arises from the arch 

 of the aorta. The two vessels, therefore, in the first part of their course, differ 

 in length, direction, and relation with neighboring structures. 



In order to facilitate the description of these vessels, more especially from a 

 surgical point of view, each subclavian artery has been divided into three parts. 

 The first portion, on the right side, passes 

 upward and outward from the origin of the 

 vessel to the inner border of the Scalenus 

 anticus. On the left side it ascends nearly 

 vertically, to gain the inner border of that 

 muscle. The second part passes outward, 

 behind the Scalenus anticus; and the third 

 part passes from the outer margin of that 

 muscle, beneath the clavicle, to the outer 

 border of the first rib, where it becomes the 

 axillary artery. The first portion of these 

 two vessels differs so much in its course and 

 in its relations with neighboring parts 

 that it will be described separately. The 

 second and third parts are alike on the two 

 sides. 



First Part of the Right Subclavian Artery (Fig. 457). The first part of 

 the right subclavian artery arises from the innominate artery, opposite the upper 

 part of the right sternoclavicular articulation, and passes upward and outward 

 to the inner margin of the Scalenus anticus muscle (Fig. 457). It ascends a little 

 above the clavicle, the extent to which it does so varying in different cases. 



Relations. It is covered, in front, by the integument, superficial fascia, Platysma, deep 

 fascia, the clavicular origin of the Sternomastoid, the Sternohyoid, and the Sternothyroid muscles, 

 and another layer of deep fascia. It is crossed by the internal jugular and vertebral veins, 

 and by the vagus nerve and the cardiac branches of the vagus and sympathetic nerves. A loop 

 of the sympathetic nerve itself also crosses the artery, forming a ring (ansa subclama) around 

 the vessel. The anterior jugular vein passes outward in front of the artery, but is not in contact 

 with it, being separated from it by the Sternohyoid and Sternothyroid muscles. Below and 

 behind the artery is the pleura, which separates it from the apex of the lung; behind is the gan- 

 gliated cord of the sympathetic, the Longus colli muscle and the first thoracic vertebra. The 

 right recurrent laryngeal nerve winds around the lower and back part of the vessel. 



4.0 



FIG. 456. Plan of the branches of the right 

 subclavian artery. 



