264 FASCIAE OF THE HEAD AND I\ECK. 



taneous vessels and nerves ; as the superficial epigastric artery, the sapne- 

 nous veins, the radial and ulnar veins, the superficial lymphatic vessels, 

 also the cutaneous muscles, as the platysma myoides, orbicularis palpe- 

 brarum, sphincter ani, &c. In other situations, the c ell ulo- fibrous fascia 

 is found condensed into a strong and inelastic membrane, as is exemplified 

 in the deep fascia of the neck, the thoracic, transversalis, and perineal 

 fasciae, and the sheaths of vessels. 



The aponeurotic fascia is the strongest kind of investing membrane ; it 

 is composed of tendinous fibres, running parallel with each other, and 

 connected by other fibres of the same kind passing in different directions. 

 When freshly exposed, it is brilliant and nacreous, and is tough, inelastic, 

 and unyielding. In the limbs it forms the deep fascia, enclosing and 

 forming distinct sheaths to all the muscles and tendons. It is thick upon 

 the outer and least protected side of the limb, and thinner upon its inner 

 side. It is firmly connected to the bones, and to the prominent points of 

 each region, as to the pelvis, knee, and ankle, in the lower, and to the 

 clavicle, scapula, elbow, and wrist, in the upper extremity. It assists the 

 muscles in their action, by keeping up a tonic pressure on their surface ; 

 aids materially in the circulation of the fluids in opposition to the laws of 

 gravity ; and in the palm of the hand and sole of the foot is a powerful 

 protection to the structures which enter into the composition of these re- 

 gions. In some situations its tension is regulated by muscular action, as 

 by the tensor vagina? femoris and gluteus maximus in the thigh, by the 

 biceps in the leg, and by the biceps and palmaris longus in the arm ; in 

 other situations it affords an extensive surface for the origin of the fibres 

 of muscles. 



The fasciae may be arranged like the other textures of the body into, 1. 

 Those of the head and neck. 2. Those of the trunk. 3. Those of the 

 upper extremity. 4. Those of the lower extremity. 



FASCIAE OF THE HEAD AND NECK. 



The TEMPORAL FASCIA is a strong aponeurotic membrane which covers 

 in the temporal muscle at each side of the head, and gives origin by its 

 internal surface to some of its muscular fibres. It is attached to the whole 

 extent of the temporal ridge above, and to the zygomatic arch below ; in 

 the latter situation it is thick and divided into two layers, the external 

 being connected to the upper border of the arch, and the internal to its 

 inner surface. A small quantity of fat is usually found between these two 

 layers, together with the orbital branch of the temporal artery. 



CERVICAL FASCIA. The fascia? of the neck are the superficial and the 

 deep. The superficial cervical fascia is a part of the common superficial 

 fascia of the entire body, and is only interesting from containing between 

 its layers the platysma myoides muscle. 



The deep cervical fascia is a strong cell ulo- fibrous layer which invests 

 the muscles of the neck, and retains and supports the vessels and nerves. 

 It commences posteriorly at the ligamentum nuchae, and passes forwards 

 at each side beneath the trapezius muscle to the posterior border of the 

 sterno-mastoid ; here it divides into two layers, which embrace that muscle 

 and unite upon its anterior border to be prolonged onwards to the middle 

 line of the neck, where it becomes continuous with the fascia of the oppo- 

 sttc side. Besides thus constituting a sheath for the sterno-mastoid, it 



