DISSECTION OF FRONT OF FOREARM. 



Superficial 

 flexor of 

 fingers : 

 origin from 

 three bones 

 of limb; 



insertion ; 

 relations ; 



use on 

 fingers, 



on elbow 

 and wrist. 



Ulnar artery 

 ends in palm 

 of hand. 



Course in 

 upper half 



and rela- 

 tions to 

 muscles ; 



in lower 

 half ; 



relations to 

 muscles : 



near the inner condyle of the humerus, and turned to one side. 

 Small branches of the ulnar artery and median nerve may be seen 

 entering the under-surfaces of those muscles. For the present the 

 pronator teres may be left uncut. 



The PLEXOR SUBLIMIS DiGiTORUM (flexor perforatus, fig. 24, 6 ) is 

 the largest of the superficial muscles, and is named from its position 

 to another flexor in the deep set. It arises in common with the 

 foregoing muscles from the inner condyle of the humerus and the 

 intermuscular septa, also from the internal lateral ligament of the 

 elbow-joint and the inner margin of the coronoid process of the 

 ulna, and by a thin layer from the oblique line of the radius, as well 

 as frequently from the anterior border of that bone for a distance of 

 one or two inches below the insertion of the pronator teres (fig. 25). 

 Below the middle of the forearm the muscle ends in four tendons, 

 which are continued beneath the annular ligament and through the 

 hand, to be inserted into the middle phalanges of the fingers (fig. 32, 

 p. 78), after being perforated by the tendons of the deep flexor. 



The flexor sublimis is in great part concealed by the other 

 muscles of the superficial group ; 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 condylar and coronoid attachments the 

 muscle will be seen to cover two deep flexors (flexor profundus 

 digitorum and flexor longus pollicis), the median nerve, and the 

 upper part of the ulnar artery. 



Action. The flexor bends first the middle and then the proximal 

 joints of the fingers ; but when the first phalanges are fixed by the 

 extensor of the fingers, the superficial flexor moves the second 

 phalanges alone. 



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

 wrist and elbow-joints. 



The ULNAR ARTERY (fig. 26, 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 supplies most of the fingers. 

 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 side of the limb. It courses 

 between the superficial and deep muscles, being covered by the 

 pronator teres, flexor carpi radialis, palmaris longus, and flexor 

 sublimis. Beneath it lies on the brachialis anticus for a short 

 distance, and afterwards on the flexor profundus (c). 



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

 and is covered by the integuments and fascia, and by the flexor 

 carpi ulnaris. To the outer side are the tendons of the flexor 

 sublimis. Beneath it is the flexor profundus (c). 



