MUSCLES OF EXPRESSION 89 



MUSCLES OF HEAD, AND FRONT AND SIDE OF THE NECK. 



The muscles of expression are those of the scalp and face. 

 They are closely connected with the under surface of the skin, or 

 with each other; they have no deep fascia over them, and there- 

 fore their slightest contraction is shown on the face, thus varying 

 the movements and lines of expression. 



Epicranial muscle. On the forehead and the top and back 

 of the head a broad thin muscle made up of two distinct parts 

 with an aponeurosis between them. The posterior part is the 

 occipitalis, taking origin from the curved line of the occipital 

 bone and ending in the aponeurosis on the top of the head. The 

 anterior part is the frontalis, having origin in the aponeurosis, 

 and passing down over the forehead to the insertion in the tissues 

 of the eyebrows. 



Action. Principally to lift the eyebrows, producing the trans- 

 verse wrinkles across the forehead which express surprise. The 

 skin is closely connected with this double muscle so that the 

 contraction causes movement of the scalp. (Some people can 

 move the scalp backward and forward by contracting the two 

 portions alternately.) 



The aponeurosis extends in a thin layer at the side over the temporal 

 region, giving origin to certain small muscles which move the ear. The scalp 

 and ear usually move together. 



Nerve. Seventh cranial (or facial}. 



Levator. palpebrae (elevator of the eyelid). Within the orbit. 

 Origin. At the apex of the orbit. Insertion. In the upper lid. 

 Action. It lifts the lid and opens the eye. 



Nerve. Seventh cranial. See page 343 for other Orb tal Muscles. 



Corrugator. The muscle which wrinkles the eyebrow. 

 Origin. The frontal bone. Insertion. The under surface of 

 eyebrow. 



Action. It draws the brows downward and inward toward 

 each other; it is the frowning muscle. 



Nerve. Seventh cranial. 



Orbicularis oculi. The ring-like muscle of the eyelid. It is 

 attached to the medial border of the orbit. Some of its fibers 

 are in the lid the palpebral portion while others surround the 



