NECK. 



constitutes, in lean subjects, a manifest and 

 resisting lamina, yet, in those of an opposite 

 character, it is rendered indistinct by the pre- 

 dominant adipose tissue which occupies its 

 areolsE. Along the side of the neck, from the 

 clavicle to the jaw, these layers are kept asun- 

 der by the platysma myoides, which adds, as 

 it were, a third lamina to the subcutaneous ex- 

 pansion; but both in front and behind, where 

 the muscle ceases, they are in close relation, 

 and constitute a single covering to those regions 

 of the neck. The deep layer of this fascia is 

 traversed by the cutaneous nerves and vessels, 

 including the external jugular vein. 



2. The cervical fascia is a proper aponeu- 

 rotic investment of this region, and corresponds 

 in its general characters to the fibrous sheath- 

 ings of the limbs. Like these, it not only 

 forms a general, compressive, and modelling 

 cincture for the part, but, by various secondary 

 splittings, furnishes dissepiments which isolate 

 the different organs, and allot to each its proper 

 sheath or fascial chamber. It may be briefly, 

 but insufficiently, described as originating from 

 a kind of linen alba, or mesial commissure in 

 front, and in its backward course to the spinous 

 processes furnishing a separate investment to 

 every organ which it encounters, and attaching 

 itself, both below and above, to the chief bony 

 eminences which present themselves. (A sec- 

 tion of it, as it thus cellulates the neck, is re- 

 presented, with Bourgery's almost invariable 

 accuracy, in a lithograph, (vol. vi. pi. 10,) from 

 which the accompanying woodcut is copied.) 

 It requires, in at least many regions of the 

 neck, a more particular description than this 

 summary contains ; and I shall accordingly 

 proceed to consider such portions of it with 

 some detail. The sterno-cleido-mastoideus is 

 ensheathed through its whole extent; the fascia, 

 on reaching its anterior edge, is bi-laminated, 

 encloses the muscle, and becomes again single 

 at its posterior border. When this sheath is 

 laid open by removing its anterior wall, and the 

 muscle carefully everted from its prismatic cell, 

 it will be seen that the posterior lamina is of 

 greater strength than the removed anterior one ; 

 and this surface is the one from which the dis- 

 sector may most conveniently trace the further 

 spread of the membrane. He will find that 

 the cervical fascia (of which the portion cover- 

 ing the sterno-cleido-mastoideus is but a se- 

 condary slip) extends itself from behind that 

 muscle in all directions; inwardly to the me- 

 sial line, outwardly to the trapezius, up- 

 wardly to the jaw, downwardly to the cla- 

 vicle. . Traced inwardly, its arrangement 

 differs in the upper and lower parts of the 

 neck: 1. in that below the os hyoides a su- 

 perficial lamina covers the subhyoid muscles, 

 joins its fellow in the median line, and is fixed 

 below to the interclavicular notch of the ster- 

 num ; a second, thin process divides the sterno- 

 thyroid from the sterno-hyoid muscle; a third, 

 stronger one, passing between the sterno-thy- 

 roid and air-tube, covers this latter organ and 

 the thyroid body, is attached below to the inner 

 surface of the manubrium sterni, internally joins 

 the layer from the opposite side, and helps with 



it to form a raphe, reaching from the os hyoides 

 to the sternal notch. Previously to the divi- 

 sions here mentioned, the fascia encloses the 

 flat tendon and anterior belly of the omo-hyoid 

 muscle; and in a line, which will presently be 

 more particularly indicated, covers the carotid 

 artery, jugular vein, and nervus vagus. Just 

 external to these parts, along the outer edge of 

 the jugular vein, it detaches a delicate process, 

 which passc.'S behind the vessels, separating 

 them from the sympathetic nerve, and is con- 

 tinued inwardly to join its fellow from the 

 opposite side, as a cellular clothing to the 

 oesophagus. 2. Above the os hyoides, the 

 arrangement of the fascia is simpler; covering 

 the mylo-hyoid and submaxillary gland, and 

 inclosing the anterior belly of the digastric, it 

 is fixed to the lower border of the symphysis, 

 and hence to a mesial raphe as far as the os 

 hyoides. It has some deep connexions, to which 

 I shall return directly; and, to the sheath of the 

 great cervical vessels it preserves the same re- 

 lations as below, its deepest process losing 

 itself on the pharynx, b. Traced upwardly, the 

 fascia is seen to split on the inferior edge of the 

 digastric muscle; the superficial lamina is at- 

 tached, behind, to the mastoid process, in 

 front, joining the part last described, to the 

 lower edge of the jaw, and, intermediately, 

 ascends upon the parotid gland, which it in- 

 vests ; the deeper layer is fixed to the styloid 

 process of the temporal bone, and gives origin 

 to a remarkable septal slip, (sometimes called 

 the stylo-maxillary ligament,) which, just in 

 front of the posterior belly of the digastric, passes 

 outwardly, is inserted into the deep surface of 

 the superficial lamina and into the angle of the 

 jaw, so serving to separate the space, circum- 

 scribed by the digastric muscle, into two parts, 

 and isolating the parotid gland, which occupies 

 the posterior of these, from the submaxillary, 

 which is situated in the anterior one. Further, 

 this deep layer (joined by a slip from the fascia, 

 which covers the submaxillary gland and is at- 

 tached to the jaw) prolongs itself around VVhar- 

 ton's duct, between the mylo-hyoid and hyo- 

 glossal muscles, and likewise furnishes origin 

 to the investing cellular tissue of the pharynx. 

 c. Below, the cervical fascia attaches itself 

 around the insertions of the muscles, which it 

 incloses, viz. towards the median line to the 

 notch of the sternum, and with the sub-hyoid 

 muscles to the deep surface of the manubrium 

 and to the cartilage of the first rib, and then to 

 the clavicle in its entire length, both around 

 and between the sterno-cleido-mastoid and tra- 

 pezius. In descending to the clavicle, it en- 

 sheathes the posterior belly of the omo-hyoid ; 

 and a firm process of it, folded around this 

 muscle and directed backward to the levator 

 anguli scapulae, is infixed along the superior 

 costa of that bone, and circumscribes the so- 

 called omo-hyoid space, d. Traced outwardly 

 and backwardli/ the fascia covers in the inter- 

 val between the trapezius and sterno-mastoid 

 (posterior triangle) from the clavicle to the oc- 

 ciput, and, on arriving at the anterior edge of 

 the trapezius, splits to enclose it. The further 

 distribution of it, in this direction, is in ac- 



