FUNCTIONS OF LOCOMOTION. 81 



TABLE OF THE PRINCIPAL SKELETAL MUSCLES. 

 (See Figs. 43 and 44.) 



THE HEAD. 



Occipito-frontalis, moves the scalp. 

 Orbicularis palpebrarum, closes the eye. 

 Orbicularis oris, closes the lips. 

 Masseter, \ . 

 Temporal, j elevate the lower jaw. 



Digastric, depresses the lower jaw. 



THE NECK. 



Slerno-cleido-mastoid, moves the head forward or to one side. 

 Trapezius (7), moves the head and neck backward. 



THE TRUNK (anterior). 

 Diaphragm, muscle of respiration. 

 Pecto*-alis major, moves the humerus and scapula. 

 SerratuK magnus, aids in violent respiration. 

 Intercostals, muscles of respiration. 



Obliquus externus (26), ) assists in violent expiration. 

 Obliquus internus, ' bends the body forward. 



THE TRUNK (posterior). 



Rhomboidens major, J moye ^ ^ backwafd 



Rhomboiaeus minor, > 



Latissimus dorsi (24), moves the humerus downward and backward. 

 Serratus posticus inferior, muscle of expiration. 



THE UPPER EXTREMITY. 

 Deltoid (8), elevates the arm. 

 Subscapularis, -\ 



Supraspinatus, v rotate the humerus. 

 Infraspinatus (12), > 

 Brachialisantieu S ,l m 



Sleeps, 



^' ceps(10) '} extend the forearm. 

 Anconeus, J 



Flexor carpi ulnaris and radialis, move the carpus. 



Flexor digitorum, flexes the fingers. 



Extensor carpi radialis and ulnaris (21), antagonize the flexors. 



Extensor digitorum (22), antagonizes the flexors. 



(Upward of thirty muscles act on the fingers.) 



