x g ATLAS AND TEXT-BOOK OF HUMAN ANATOMY. 



Fig. 2 6o.-The superficial layer of the facial muscles and the neighboring muscles of the neck seen 

 from the side and slightly from in front. 



Ftg 261 — The orbicularis oculi seen from behind. 



The muscle together with the integument has been removed; the lachrymal portion is represented m connection 

 with the inner margin of the orbit. 



THE MUSCLES OF THE FACE AND OF THE SCALP. 



The cutaneous muscles of the face exhibit manifold peculiarities by which they are more or 

 less differentiated from the ordinary skeletal muscles. They possess no fasciae, they exhibit but 

 a slight degree of independence, and many of them are so combined and their fibers interlace to 

 such an extent that it is often purely a matter of choice whether individual fasciculi are regarded as 

 special muscles or as the heads of a larger muscle. The arrangement of the facial muscles into 

 sphincters or muscles of closure is also characteristic. The group includes the epicranius as 

 well as the muscles of the face proper. 



THE EPICRANIUS. 



The epicranius (Figs. 260, 262, and 264) consists of a middle aponeurosis which envelops 

 the cranium the galea aponeurotica, and of muscles which arise in the frontal and occipital regions 

 and are inserted into the galea. This is thickest in the occipital region, becomes thinner toward 

 the forehead and particularly toward the temples, and gradually loses its aponeurotic character 

 (especially in the temporal region). It is connected to the skin by fibrous connective-tissue 

 fasciculi and separated from the cranial periosteum by loose areolar tissue. 



The frontalis is a very thin, broad, and flat muscle which is intimately adherent to the skin 

 of the eyebrows. It has a broad origin above the supraorbital margin, extends over the vertical 

 portion of the frontal bone, and is inserted into the galea aponeurotica in the upper portion of the 

 forehead. It has also a slender origin, which varies in size, from the bony bridge of the nose; 

 when stronglv developed, it is known as the procerus (pyramidalis) nasi, but it is always 

 immediately connected with the frontalis. The two frontales are separated in the median line 

 by a narrow area containing no muscular tissue. 



The occipitalis is also a flat, broad, and an approximately quadrilateral muscle which arises 

 on each side by short tendinous fibers from the highest nuchal line; it passes upward, and after 

 a comparatively short course is inserted into the galea aponeurotica in the occipital region. The 

 width of the muscle is much greater than its height, in contrast to the opposite condition in the 

 frontalis. 



Like all the facial muscles, the frontalis and the occipitalis are supplied by the facial nerve. 



Both muscles are tensors of the galea aponeurotica. They pull the scalp forward or backward, and the frontalis 

 wrinkles the skin of the forehead. 



A portion of the auricularis is also related to the galea aponeurotica. This muscle presents 

 three portions, an auricularis anterior, superior, and posterior, and like almost all the facial muscle; 

 they are subject to great individual variations in the degree of their development. 



