THE HEART AND VASCULAR SYSTEM. 191 



In the hand: 



Princeps pollicis, supplies the sides of the palmar aspect of the 

 thumb ; 



Radialis indicis, supplies the radial side of index finger ; 



Perforating, anastomose with dorsal interosseous arteries; 



Interosseous, anastomose with digital branches of superficial 

 palmar arch. 



THE ULNAR ARTERY 



descends from the bifurcation of the brachial below the bend 

 of the elbow to the ulnar border of the wrist, passing beneath 

 all the superficial flexors excepting the flexor carpi ulnaris, 

 crosses over the annular ligament at the radial side of pisiform 

 bone, and enters the palm to form the superficial palmar arch, 

 anastomosing with the superficialis volae from the radial. Its 

 branches are, in the forearm : 



Anterior ulnar recurrent, supplies the pronator radii teres and 

 brachialis anticus muscles; 



Posterior ulnar recurrent, supplies the joint and neighboring 

 muscles, and anastomoses freely; 



Interosseous, passes backward to the upper border of the inter- 

 osseous membrane, where it divides into 



Anterior branch, descends on the front of the interosseous 



membrane ; 

 Posterior, descends on the posterior aspect of the foramen and 



gives off a recurrent interosseous branch; 

 Muscular, to muscles on ulnar side of forearm. 



In the wrist: 



Anterior carpal, supplies the front of wrist and anastomoses with 

 the carpal branches of radial artery; 



Posterior carpal, passes beneath the tendon of flexor carpi ulnar is 

 and forms posterior carpal branch. 



In the hand: 



Deep, or communicating branch, passes between the flexor and 

 abductor minimi digiti to form part of deep palmar arch: 



Digital, supply the ulnar side of the little finger and adjoining 

 sides of the little, ring, middle, and index fingers. 



THE DESCENDING AORTA. 



The thoracic aorta extends from the lower border of the 

 fifth dorsal vertebra on the left side to about the last dorsal 

 vrrirlira, where by passing through the aortic opening in the 

 diaphragm it becomes the abdominal aorta. 



Relation*. It is in relation in front with tho left bronchus, crsopli 

 agus, pericardium, and left pulmonary artery; behind it rests upon the 



