316 MUSCLES AND FASCIA. 



the margin of the anus ; and is almost entirely wanting in the palms of the 

 hands and soles of the feet, where the integument is adherent to the subjacent 

 aponeurosis. The superficial fascia connects the skin to the subjacent parts, 

 facilitates the movement of the skin, serves as a soft nidus for the passage of 

 vessels and nerves to the integument, and retains the warmth of the body, since 

 the adipose tissue contained in its. areolaa is a bad conductor of caloric. 



The aponeurotic or deep fascia is a dense inelastic and unyielding fibrous 

 membrane, forming sheaths for the muscles, and affording them broad surfaces 

 for attachment. It consists of shining tendinous fibres, placed parallel with 

 one another, and connected together by other fibres disposed in a reticular 

 manner. It is usually exposed on the removal of the superficial fascia, form- 

 ing a strong investment, which not only binds down collectively the muscles 

 in each region, but gives a separate sheath to each, as well as to the vessels 

 and nerves. The fasciae are thick in unprotected situations, as on the outer 

 side of a limb, and thinner on the inner side. Aponeurotic fascias are 

 divided into two classes, aponeuroses of insertion, and aponeuroses of in- 

 vestment. 



The aponeuroses of insertion serve for the insertion of muscles. Some of these 

 are formed by the expansion of a tendon into an aponeurosis, as, for instance, 

 the tendon of the Sartorius ; others are connected directly to the muscle, as the 

 aponeuroses of the abdominal muscles. 



The aponeuroses of investment form a sheath for the entire limb, as well as for 

 each individual muscle. Many aponeuroses, however, serve both for invest- 

 ment and insertion. Thus the aponeurosis given off from the tendon of the 

 Biceps of the arm near its insertion is continuous with, and partly forms, the 

 investing fascia of the forearm, and gives origin to the muscles in this region. 

 The deep fasciaa assist the muscles in their action, by the degree of tension and 

 pressure they make upon their surface; and, in certain situations, this is in- 

 creased and regulated by muscular action, as, for instance, by the Tensor 

 Vaginas Femoris and Gluteus Maximus in the thigh, by the Biceps in the leg, 

 and Palmaris Longus in the hand. In the limbs, the fascia3 not only invest the 

 entire limb, but give off septa, which separate the various muscles, and are 

 attached beneath to the periosteum ; these prolongations of fasciaa are usually 

 spoken of as intermuscular septa. 



The Muscles and Fasciaa may be arranged, according to the general division 

 of the body, into those of the head, face, and neck ; those of the trunk ; those 

 of the upper extremity ; and those of the lower extremity. 



MUSCLES AND FASCIA OF THE HEAD AND FACE. 



The Muscles of the Head and Face consist of ten groups, arranged according 

 to the region in which they are situated. 



1. Cranial Eegion. 6. Superior Maxillary Eegion. 



2. Auricular Kegion. 7. Inferior Maxillary Kegion. 



3. Palpebral Eegion. 8. Intermaxillary Eegion. 



4. Orbital Eegion. 9. Temporo-maxillary Eegion. 



5. Nasal Eegion. 10. Pterygo-maxillary Eegion. 



The Muscles contained in each of these groups are the following : : 



1. Cranial Region. 



~ . ., n , v 3. Palpebral Region. 



Occipito-irontalis. 



Orbicularis Palpebrarum. 



2. Auricular Region. Corrugator Supercilii. 



Attollens Aurem. Levator Palpebrae. 



Attrahens Aurem. Tensor Tarsi. 



Retrahens Aurem. 



