20 THE SURGICAL ANATOMY OF THE HORSE 



The muscle is an adductor of the limb and extends the shoulder. It 

 is supplied by the median nerve. 



The Biceps (29). — Most of this muscle is represented on this aspect of 

 the limb, though its origin from the coracoid process is better seen on the 

 outer aspect. The belly of the muscle is thick and fusiform in shape, 

 and through it a fibrous cord runs. The muscle lies on the front of the 

 humerus. Its inferior tendon is thick, and powerful, and plays over the 

 anterior common ligament of the elbow, to which it is closely adherent, 

 to run to its insertion into the bicipital tuberosity, which is placed 

 anteriorly at the upper extremity of the radius and towards its inner 

 side. A strong band of fibrous tissue called the bicipital fascia is given 

 off from the muscle. This runs downwards and outwards to be attached 

 to the sheath of the extensor metacarpi magnus and the deep fascia of 

 the forearm. 



The biceps is a flexor of the elbow, a slight extensor of the forearm, 

 and makes the fascia of the latter tense. The median nerve supplies 

 this muscle. 



The Extensor Metacarpi Magnus (37 and 47). — The belly and 

 tendons of this muscle are also seen on this aspect of the limb. The 

 muscle has previously been described. 



The Flexor Metacarpi Internus (35). — This muscle lies on the posterior 

 aspect of the radius and is closely applied to its inner edge. Between 

 the muscle and the bone the posterior radial vessels and the median 

 nerve run. It arises from the inner condyle of the humerus, where it 

 has a common origin with the middle flexor. Its inferior tendon is long 

 and slender. It passes through a synovial sheath vertically across the 

 inner aspect of the knee, to be inserted into the head of the inner small 

 metacarpal bone. 



It is a flexor of the knee, and is supplied by the median nerve. 



The Flexor Metacarpi Medius (36). — This muscle arises by two heads: 

 the anterior head has a common origin with the preceding muscle, 

 and the posterior head arises from the olecranon process. The ulnar 



