OF THE UPPER EXTREMITY 











the axillary border of the scapula; the scapular circumflex is given off the sub- 

 scapular opposite the midpoint of a line joining the tip of the acromion to the 

 lower edge of the deltoid tuberosity, while the humeral circumflex arteries arise 

 from the axillary about 2 cm. above this. The position of the brachial artery is 

 marked by a line drawn from the junction of the anterior and middle thirds of the 

 distance between the anterior and posterior axillary folds to a point midway 

 between the epicondyles of the humerus and continued distally for 2.5 cm., at 

 which point the artery bifurcates. With regard to the branches of the brachial 

 artery the profunda crosses the back of the humerus at the level of the insertion 

 of Deltoideus; the nutrient is given off opposite the middle of the body of the 

 humerus; a line from this point to the back of the medial condyle represents 

 the superior ulnar collateral ; the inferior ulnar collateral is given off about 5 cm. 

 above the fold of the elbow-joint and runs directly medial ward. 



The position of the radial artery in the forearm is represented by a line from the 

 lateral margin of the Biceps tendon in the center of the anticubital fossa to the 

 medial side of the front of the styloid process of the radius when the limb is 

 in the position of supination. The situation of the distal portion of the artery 

 is indicated by continuing this line 

 around the radial side of the wrist 

 to the proximal end of the first inter- 

 metacarpal space. 



On account of the curved direction 

 of the ulnar artery, two lines are re- 

 quired to indicate its course; one is 

 drawn from the front of the medial 

 epicondyle to the radial side of the 

 pisiform bone; the lower two-thirds 

 of this line represents two-thirds of 

 the artery; the upper third is repre- 

 sented by a second line from the center 

 of the hollow in front of the elbow- 

 joint to the junction of the upper and 

 middle thirds of the first line. 



The superficial volar arch (Fig. 1237) 

 can be indicated by a line starting 

 from the radial side of the pisiform 

 bone and curving distalward and 

 lateralward as far as the base of the 

 thumb, with its convexity toward the 

 fingers. The summit of the arch is 

 usually on a level with the ulnar 

 border of the outstretched thumb. 

 The deep volar arch is practically 

 transverse, and is situated about 1 

 <3m. nearer to the carpus. 



Nerves (Figs. 1235, 1236). In the 

 arm the line of the median nerve is 

 practically the same as that for the 

 brachial artery; at the bend of the 

 elbow the nerve is medial to the 



artery. The course of the nerve in the forearm is marked by a line starting 

 from a point just medial to the center of one joining the epicondyles, and ex- 

 tending to the lateral margin of the tendon of Palmaris longus at the wrist. 



The ulnar nerve follows the line of the brachial artery in the upper half of the 



Badial artery \- L - 



Ulnar 

 artery 



FIG. 1237. Palm of left hand, showing position of skin 

 creases and bones, and surface markings for the volar 

 arches. 



