ULNAR ARTERY AND BRANCHES. 26l 



the bones of the forearm, viz., from the inner part of the coronoid process 

 of the ulna ; from the oblique line below the radial tubercle ; and from the 

 anterior margin of the radius as far as, or one or two inches below the 

 insertion of the pronator teres. Rather below the middle of the forearm 

 the muscle ends in four tendons, which are continued beneath the annular 

 ligament and across the hand, to be inserted into the middle phalanges of 

 the fingers, after being perforated by the tendons of the deep flexor. 



The flexor sublimis is concealed by the other muscles of the superficial 

 layer ; and the radial vessels lie on the attachment to the radius. Along 

 the inner border is the flexor carpi ulnaris, with the ulnar vessels and 

 nerve. The tendons of the muscle are arranged in pairs before they pass 

 beneath the annular ligament of the wrist ; the middle and ring finger 

 tendons being anterior, and those of the index and little finger posterior in 

 position. On dividing the coronoid and condyloid attachments, the muscle 

 will be seen to cover two flexors of the deep layer (flexor digitorum pro- 

 fundus and flexor pollicis), the median nerve, and the upper part of the 

 ulnar artery. 



Action. This flexor bends primarily the middle joint of each finger ; and 

 is then able to bring the nearest phalanx towards the palm in consequence 

 of being bound thereto by a sheath. But when the nearest phalanx is 

 fixed by the extensor of the fingers, it remains straight whilst the super- 

 ficial flexor moves the second phalanx. 



After the fingers are bent the muscle will help in flexing the wrist and 

 elbow joints. 



The ULNAR ARTERY (fig 81, G ) is the larger of the two branches coming 

 from the bifurcation of the brachial trunk ; and is directed along the inner 

 side of the limb to the palm of the hand, where it forms the superficial 

 palmar arch, and joins offsets of the radial artery. In the forearm the 

 vessel has an arched direction ; and its depth from the surface varies in 

 the first and last parts of its course. 



In the upper half the artery is inclined obliquely inwards from the 

 centre of the elbow to the inner part of the limb, midway between the 

 elbow and wrist. It courses between the superficial and deep layers of 

 muscles, being covered by the pronator teres, flexor carpi radialis, palmaris 

 longus, and flexor sublimis. Beneath it lie the brachialis anticus, for a 

 short distance, and the flexor profundus, c. 



Veins. Two companion veins are situate on the sides of the artery, 

 and join freely over it. 



Nerves. The median nerve ( ] ) lies to the inner side of the vessel for 

 about an inch, but then crosses over it to gain the outer side. About the 

 middle of the forearm the ulnar nerve ( 4 ) approaches the artery and con- 

 tinues thence on the inner side. 



In the lower half it has a straight course to the pisiform bone, and is 

 covered by the teguments and fascia, and the flexor carpi ulnaris as far as 

 the wrist. To the outer side are the tendons of the flexor sublimis. Be- 

 neath it is the flexor profundus, c. 



Veins. Two companion veins accompany the artery, as in the upper 

 part, and are united across it at intervals. 



Nerves. The ulnar nerve ( 4 ) lies close to, and on the inner side of the 

 vessels ; and a small branch ( 5 ), sending twigs around the artery, courses 

 to the palm of the hand. 



On the annular ligament of the wrist the artery lias passed through the 



