58 



ANATOMY FOE, NURSES. 



[CHAP. VI. 



tables of Liebig: skeleton, twenty-eight pounds; muscles, sixty- 

 two pounds ; viscera (with skin, fat, blood, etc.), sixty pounds. 

 The total number of voluntary muscles may be stated at 

 three hundred and eleven. It is not necessary for us to be able 

 to distinguish more than a few of the most prominent. We 

 may conveniently classify these into two groups : 



1. Chief muscles of the head and trunk. 



2. Chief muscles of the limbs. 



Chief muscles of head, face, neck, and trunk. The chief 

 muscles of the head are the occipital and frontal muscles, 



which, united together by a thin 

 aponeurosis extending over and 

 covering the whole of the upper 

 part of the cranium, are usually 

 known as one muscle, the occipito- 

 frontalis. The frontal portion of this 

 muscle is the more powerful ; by 

 its contraction the eyebrows are ele- 

 vated, the skin of the forehead 



FIG. 55. MUSCLES OF RIGHT 

 EYEBALL WITHIN THE ORBIT. 

 Seen from the front. 21, superior thrown into transverse wrinkles, and 



rectus; 22, inferior rectus: 23, ex- f i soa l n drawn forward 

 ternal rectus; 24, internal rectus; 

 25, superior oblique; 26, inferior 

 oblique. 



\ 



There are about thirty facial mus- 

 cles ; they are chiefly small, and con- 

 trol the movements of the eye, nose, and mouth. 



The six muscles which move the eyeball are the four straight 

 or recti, and the two oblique, 

 muscles. The four recti have a 

 common origin at the bottom 

 of the orbit ; they pass straight 

 forwards to their insertion into 

 the eyeball, one, the superior 

 rectus, in the middle line above ; 

 one, the inferior rectus, oppo- 

 site it below, and one half-way 

 on each side, the external and 

 internal recti. The eyeball is 



Completely imbedded in fat, and from side - 1!) ' elevator muscle of eyelid; 



22-2(5, same as in Fig. 55. 



these muscles turn it as on a 



cushion, the superior rectus inclining the axis of the eye upwards, 



FIG. 56. MUSCLES OF EYEBALL. Seen 



