INNER ASPECT OF LIMB 29 



continues its downward course behind this vessel and in front of the 

 posterior radial vein. With the two vessels named it crosses the angle 

 formed by the humerus and radius, and disappears between the inner 

 edge of the latter bone and the flexor metacarpi internus muscle. In this 

 situation the nerve is covered by the posterior superficial pectoral muscle, 

 which has been removed to expose it and the accompanying vessels. 



Running down the back of the radius, the nerve divides, at a 

 point which is variable in the forearm, into two branches. One of 

 these (40) makes its appearance in the plate just above the carpus, 

 between the middle and internal flexors of the metacarpus. It runs 

 at first outside the fibrous arch enclosing the carpal sheath, and on 

 the surface of this band it unites with the before-mentioned branch 

 of the ulnar nerve to form the external plantar. 



The other division of the median passes through the carpal arch 

 on the inner edge of the perforans tendon, and is directly continued 

 as the internal plantar nerve. 



Nerve to the Biceps and Coraco-humeralis Muscles (23). — This is 

 the musculo-cutaneous or anterior brachial nerve of Chauveau. It 

 may either come off from the anterior root of the median above 

 the loop for the axillary artery, as in the plate, or from the median 

 immediately below the loop. Its fibres are derived from the seventh 

 and eighth cervical nerves. The nerve descends in front of the 

 axillary artery, across the inner aspect of the shoulder joint, and then 

 passes forwards and outwards between the two insertions of the 

 coraco-humeralis muscle in company with the prehumeral artery. It 

 gives off twigs to the coraco-humeralis muscle and terminates in the 

 biceps. 



'The Musculo-cutaneous Nerve {2ja). — This is a long branch of the 

 median which is given off from the latter about half-way down the 

 shaft of the humerus. It passes obHquely downwards and forwards 

 from the parent nerve, and crosses the inferior insertion of the 

 coraco-humeralis muscle. It now places itself in company with the 



