DEEP CERVICAL FASCIA. 197 



layer of considerable firmness intervenes between the aponeurosis of the 

 occipito-frontalis muscle and the skin, uniting them together : from the 

 surface of the occipital part of the muscle it becomes continuous with a 

 superficial covering of the posterior muscles of the neck, and on each side 

 of the epicranial aponeurosis it descends over the temporal fascia, and contains 

 between its laminae the external muscles of the ear, with the superficial 

 temporal vessels and nerves. 



In the face, the fibres of the superficial muscles are frequently so much 

 incorporated with the skin, that in many parts there is no distinct intervening 

 layer of superficial fascia ; and over most of the face the subcutaneous fat 

 breaks up the fascia to a great extent. On the side of the neck, where a 

 representative of the superficial fascia is found in the tissue containing the 

 platysma myoides muscle, it is thin, and has embedded in it the external 

 jugular vein and some superficial nerves. 



The DEEP FASCIAE of the head and neck deserve special attention, as they 

 give investments of considerable strength, and serve to mark the separation 

 between several important organs. 



The temporal fascia is a structure of an aponeurotic nature, which covers 

 the temporal muscle above the zygoma, and gives extensive attachment to 

 its fibres of origin. It springs infeiiorly from the upper border of the 

 zygomatic arch, and is attached in the rest of its circumference to the 

 posterior border of the malar bone and to the temporal ridge on the 

 frontal, parietal, and temporal bones. It is divided below into two layers, 

 one of which is attached to the outer and the other to the inner surface of 

 the zygoma ; and in this situation there is deposited between its layers a 

 quantity of fat, the absorption of which is one cause of the hollowness of 

 the temples in emaciated persons. This dense fascia is separated from the 

 integuments by the layer of thin membrane descending from the epicranial 

 aponeurosis, and by the auiicular muscles; and from the temporal muscle 

 below, by a deeper layer of fat. 



The cervical fascia (named also proper or deep cervical) passes forwards 

 from the anterior border of the trapezius muscle over the sides and front 

 of the neck beneath the platysma myoides. Posteriorly it is continuous with 

 the layers of connective tissue with which the trapezius and deeper muscles 

 are invested ; it extends over the posterior triangle of the neck, viz., the 

 space bounded by the trapezius and sterno-mastoid muscles and the clavicle : 

 at the posterior border of the sterno-mastoid it divides into two layers, 

 which form an investment for that muscle ; these unite again at the anterior 

 border into a membrane which passes forwards across the middle line, and 

 covers the area bounded by the middle line, the border of the jaw, and the 

 sterno-mastoid muscle, and called the anterior triangle, In the posterior 

 triangle the fascia is attached iiiferiorly to the clavicle, and near that bone 

 is perforated by the external jugular vein, which in the previous part of 

 its course lies superficial to the membrane. In the anterior triangle 

 it is bound superiorly to the border of the jaw in front, and further back is 

 continued over the masseter muscle (masseteric fascia), and the parotid gland, 

 which it closely invests (parotid fascia) ; it likewise sends upwards a pro- 

 cess on the posterior and deep surfaces of the parotid gland ; and a strong 

 band of this process, known under the name of the stylo-maxillary ligament, 

 extends from the styloid process to the angle of the jaw, so as to keep tha 

 parotid and submaxillary glands distinct, even although one or both of them 

 may be greatly enlarged. 



In the front of the neck the fascia is attached to the hyoid bone, arid, becom- 



