100 



ANATOMY FOR NURSES 



[Chap. VII 



upper ; they also move the lower jaw forward upon the upper, 

 and in every direction necessary to the process of grinding the 

 food. 



Muscles of expression. — These muscles are sometimes called 

 mind muscles from the indications that they afford of the mental 

 state of the individual. They are closely connected with the 

 under surface of the skin or with each other, and therefore their 

 slightest contraction is shown on the face. They include the 

 muscles of the forehead, eyelids, nose, and all those related to 



STYLOID PROCESS 



ORIGIN OF 

 BTYLOMVOID 



-MANOIBLC 



Fig. 72. — Muscles of the Tongue. Viewed from the right side. (Gerrish.) 



the orifice of the mouth. We shall only consider two important 

 muscles related to the orifice of the mouth. 



Orbicularis oris. — The ring muscle surrounds the opening of 

 the mouth, extending from the nose above to the chin below. 

 It forms a great part of the bulk of the lips, and constitutes 

 a sphincter to the mouth. It is attached above to the partition 

 between the nostrils and the upper jaw bones, and below to the 

 mandible. 



Action. — It closes the mouth. 



Buccinator (trumpeter's muscle). — This muscle arises from the 

 alveolar processes of the maxilla and mandible. Its different parts 



