subscapularis 



pectoralis minor 



coracobrachialis 



biceps brachii- 



pars ciavobrachialis^ 

 pectoralis major 



pars pectoantibrochialis anterior 

 pars pectoantibrochialis posterior 



pars pectoantibrochialis anterior 

 pars pectoantibrachiolis poster 



biceps brach 



Figure 14-6. Ventral musculature of the shoulder and upper arm of the cat. A, ventral superficial 

 layer; B, deeper layers reveoled by reflexing a port of the superficial layer; C, muscles of the inner 

 aspect of the scapula. 



brachioradialis; it arises from the humerus and inserts on 

 the radius and ulna. The brachioradiaUs is but a part of the 

 brachialis, which arises from the belly of that muscle and 

 extends as a narrow band out along the nerves and blood 

 vessels going to the hand. Behind the brachialis is the 

 triceps, two heads of which can ben seen. The pars lateralis 

 and the pars longum are both large bellies which taper to a 

 broad common insertion over the olecranon process of the 

 ulna. Their origins are from the head of the humerus and 

 the lower margin of the scapula respectively. If the lateral 



head of the triceps is bisected and the ends reflexed, the 

 medial head and the pars anconeus are seen. Both of these 

 arise along the humerus. On the ventral aspect is a muscle 

 similar to the pars anconeus, this is the epitrochleo-anconeus. 

 On the ventral aspect of the upper arm, with the pars 

 pectoantibrachialis raised or reflexed, is the biceps brachii, 

 as distinguished from the biceps femoris of the thigh. The 

 biceps arises from the anterior aspect of the base of the 

 coracoid process of the scapula by a long tendon and inserts 

 through a tapered tendon on the radius and ulna (along 



426 



THE MUSCULAR SYSTEM 



