APPLIED ANATOMY. 



These operations demand on the part of the surgeon an accurate knowledge 

 of the topography of the part. For our purpose we may consider the nerves of the 

 forearm as being of two kinds trunks and branches. There are two main trunks 

 the median and the ulnar ; the superficial (radial), and deep (interosseous) branches 

 of the radial (musculospiral), and forearm branches of the median and ulnar form 

 the second class. The main trunks simply traverse the forearm to be distributed 

 in the hand, therefore injury to them shows itself by disabilities of the hand. The 

 branches supplying the forearm, if of sensation, rarely give rise to any serious effects 

 requiring surgical interference. The motor branches enter the muscles of the fore- 



N. cutaneus antibrachii lateralis 

 (external or musculocutaneous) 



N. radialis, ramus profundus 

 (posterior interosseous) 



N. radialis, ramus superficialis 

 (radial nerve) 



Brachioradialis muscle 



Median nerve 



N. cutaneus antibrachii 

 medialis (internal cutaneous) 



Pronator radii teres muscle 



Ulnar nerve 



Flexor carpi radialis muscle 

 Palmaris longus muscle 

 Flexor carpi u!naris muscle 



Pisiform bone 



FIG. 331. The nerves of the forearm. 



arm so high up that paralysis usually is seen only when the nerves are injured in 

 the region of the elbow or above. The high entrance is caused by the bellies of the 

 muscles being above and the part below being tendinous (Fig. 331). 



The Median Nerve. The median nerve at the elbow-joint lies internal to 

 the brachial artery, which lies next and internal to the biceps tendon. It lies on the 

 brachialis anticus muscle and under the bicipital fascia. It crosses the ulnar artery 

 obliquely a short distance below its origin. The artery curves toward the ulnar side 

 while the nerve has a slight curve toward the radial side ; between the two passes the 

 ulnar head of the pronator radii teres muscle. The nerve then proceeds downward 



