162 



UNCONSCIOUS NERVOUS OPERATIONS 



Sifbclavian Arteries^ 



arch over the root of the left lung passes downward near 

 the spinal column. Piercing the diaphragm, the aorta 

 enters the abdomen, and at the fourth lumbar vertebra 

 divides into the right and left common iliac arteries, and a 

 third small branch (the middle sacral) which continues on 

 to the end of the coccyx. 



226. Branches of the Aorta (Figs. 85 and 93). The 

 first branches of the aorta are the two coronary arteries 

 sent off just beyond the semilunar valves to supply the 



Avails of the heart. The large 

 branches from near the top 

 of the arch are: (1) the in- 

 nominate artery, which soon 

 divides into two, the right sub- 

 clavian, running to the right 

 arm, and the right carotid, sup- 

 plying the right side of the 

 head and neck; (2) the left 

 common carotid for the left side 

 of the neck and head; and 

 (3) the left subclavian artery 

 for the left arm. Each sub- 

 clavian artery gives off at the 

 armpit the axillary and in the 

 arm the brachial artery. The 

 latter divides into the ulnar 

 and the radial arteries, named 

 from the bones along which they lie. They unite in the 

 hand to form the palmar arch. 



The carotid arteries ascend the sides of the neck and 

 divide into two branches, which supply the head and face 

 and the brain. 



The branches of the aorta within the thorax are (besides 



iini.il- I'alvea 



Fig. 93. Arch of the aorta, dis- 

 sected free from the rest of 

 the heart. 



