98 ANATOMY FOE, NUKSES. [CHAP. IX. 



subclavian, and is continued as the axillary. It gives off large 

 branches to the back, chest, and neck. 



The axillary artery passes through the axilla, lying to the 

 inner side of the shoulder joint and upper part of the arm. It 

 gives off branches to chest, shoulder, and arm. 



The brachial artery extends from the axillary space to just 

 below the bend of the elbow, where it divides into the ulnar and 

 radial arteries. It may be readily located, lying in the depres- 

 sion along the inner border of the biceps muscle. Pressure 

 made at this point on the artery, from before backwards against 

 the humerus, will control the blood supply to the arm. 



The ulnar artery, the larger of the two vessels into which the 

 brachial divides, extends along the side of the forearm into 

 the palm of the hand, where it terminates in the superficial 

 palmar arch. 



The radial artery appears, by its direction, to be a continua- 

 tion of the brachial, although it does not equal the ulnar in size. 

 It extends along the front of the forearm as far as the lower 

 end of the radius, below which it turns round the outer border 

 of the wrist, descends between the bones of the thumb and fore- 

 finger, and passes forward into the palm of the hand. It ter- 

 minates in the deep palmar arch. The superficial and deep 

 palmar arches supply the hand with blood. 



The thoracic aorta extends from the lower border of the fourth 

 dorsal vertebra, on the left side, to the opening in the diaphragm 

 below the last dorsal vertebra, and has a length of from S'even 

 to eight inches. The branches, derived from the thoracic aorta, 

 are numerous, but small. They are distributed to the walls of 

 the thorax, and to the viscera contained within it. 



The abdominal aorta commences about the lower border of the 

 last dorsal vertebra, and terminates below by dividing into the 

 two common iliac arteries. The bifurcation usually takes place 

 about half-way down the body of the fourth lumbar vertebra, 

 which corresponds to a spot on the front of the abdomen, 

 slightly below and to the left of the umbilicus. Its length is 

 about five inches. 



The abdominal aorta gives off numerous branches, which may 

 be divided into two sets ; viz. those which supply the viscera, 

 and those which are distributed to the walls of the abdomen. 

 The former consists of the creliac axis, the superior mesenteric, 



