272 



APPLIED ANATOMY. 



behind, is quite evident and marks the internal intermuscular septum, which extends 

 to the medial (internal) condyle. In front of it lie the brachial artery and veins, 

 and median and medial antebrachial {internal) cutaneous nerve. At the upper 

 portion of the inside of the arm can be seen the swell formed by the coracobrachialis 

 muscle. The inner or posterior border of the coracobrachialis is continuous with 

 the inner border of the biceps, and the brachial artery follows them. The coraco- 

 brachialis muscle ends just below the level of the insertion of the deltoid, and, of 

 course, can neither be seen nor felt below that point. It is here that the ulnar nerve 

 leaves the artery to pierce the internal intermuscular septum in company with the 

 superior ulnar collateral {inferior profunda) artery to reach the groove behind the 

 internal condyle. The brachial artery is covered only by the skin and superficial and 

 deep fascia, and can be felt pulsating along the inner edge of the biceps muscle and 

 tendon; it can be compressed against the bone by pressure directed outwardly 

 above and inclining more posteriorly as the artery progresses down toward the bend 

 of the elbow. It is on the inner side of the arm in the upper two-thirds, and is more 

 anterior in the lower one-third (Fig. 284). 



The cephalic vein runs up the external bicipital furrow and the basilic up the 

 internal. At the junction of the middle and lower thirds of the arm the basilic 

 pierces the deep fascia and from that point runs up beneath it and joins with the 

 internal vena comes opposite the lower border of the teres major or subscapularis. 



THE BRACHIAL ARTERY. 



The arm being abducted, the course of the brachial artery is indicated by a 

 line drawn from the inner edge of the coracobrachialis muscle, at the junction of 

 the. anterior and middle thirds of the axilla, above, to a point just inside the tendon 

 of the biceps at the bend of the elbow, below, midway between the two condyles 

 of the humerus. This lies in the internal bicipital furrow along the inner edge of 

 the biceps muscle. The artery is superficial in its entire course. It is accom- 

 panied by two small venae comites, which closely embrace it. The basilic vein 

 runs along its inner side. The median nerve lies on the artery to its outer side 

 above, then directly on it and a little to its inner side at the middle, and passes 

 to its inner side at the bend of the elbow. The medial antebrachial ( internal ) 

 cutaneous nerve, much smaller than the median, passes down along the inner side 

 of the artery between it and the basilic vein to pierce the fascia about the middle of 

 the arm (Fig. 285). 



The ulnar nerve lies to the inner side of the artery above and is posterior to the 

 basilic vein. About opposite the insertion of the coracobrachialis it diverges from 

 the artery to pierce the internal intermuscular septum. 



RELATIONS OF THE BRACHIAL ARTERY 



In Front. 

 Skin and fascia 



Overlapped by coracobrachialis and biceps 

 Median basilic vein 

 Bicipital fascia . 

 Median nerve 



Inner Side 



Medial antebrachial (int.) 

 Brachial cutaneous and 



Artery ulnar nerves 



Median nerve below 

 Basilic vein 

 Vena comes 

 Behind 



Triceps (long and inner heads) 

 Radial (musculospiral) nerve 

 (Sup.) profunda artery 

 Coracobrachialis muscle 

 Brachialis anticus muscle 



Oufer Side 

 Median nerve, above 

 Coracobrachialis 

 Biceps 

 Vena comes 



