FASCIA, (in general anatomy,) ( Blade, schinge Schcide, l'kchsenhaute, Germ.) This term is applied to certain membranous expan sions, existing in various regions of the body, and forming coverings to particular parts. These expansions are composed either of cellu lar tissue, more or less condensed, or of fibrous tissue, the former being the ccllularfascie, the latter the aponeuroscs or aponeurotic fascia. The structure and connexions of a considerable number of the fascia: are highly interesting, as well with reference to correct diagnosis and prognosis in surgical disease, as in regard to the mode of proceeding in various operations.
1. Cellular fascie.—These are lamellae of cellular membrane of variable density, some times loaded with fat, at other times totally devoid of it. The best example of this form of fascia is the layer of cellular membrane which is immediately subjacent to the subcutaneous cellular tissue all over the body, and in most places so intimately connected with it as to be inseparable; these in fact form but one mem brane, which, although essentially the same everywhere, yet exhibits characters peculiar almost to each region of the body; it is gene rally known under the name of the superficial fascia. Although this fascia is universal, there are, nevertheless, certain regions where, from its greater importance, it has been more care fully examined than in others, and to which we may best refer in order to investigate its pecu liar characters. Of these regions those of the abdomen and the neck stand pre-eminent; here this fascia constitutes a distinct membraniform expansion, and the principal variety it pre sents in different subjects is as regards the greater or less quantity of fat deposited in it. Where a tendinous or fibrous expansion does not lie immediately under it, this fascia sends processes from its deep surface to invest the subjacent muscles and other parts; this is very manifest in the case of the fascia of the neck ; and in general it may be stated that the super ficial fascia has a more or less intimate connec tion with the proper cellular covering of sub jacent organs, whether muscles or tendons.
The arrangement to which we allude in the fascia of the neck may be satisfactorily traced from the median line on the anterior surface of the neck, proceeding outwards on each side.
On the median line the fascia of opposite sides are intimately united so as to form a dense line, called by some anatomists linea alba cervicalis; thence on each side the fascia divides into lamina, investing the sterno-hyoid and thyroid muscles, the carotid artery and jugular vein, the sterno-mastoid, and other muscles; and thus anatomists come to describe a superficial and a deep layer of the cervical fascia; the former being continuous with the superficial fascia covering the muscles on the anterior part of the thorax, the latter, intimately con nected with all the deep-seated structures in the neck, may be traced outwards behind the sterno-mastoid muscle, along the posterior edge of which it becomes again united with the su perficial layer ; the fascia, thus re-constructed, passes through the triangular space which in tervenes between the muscle last-named and the trapezius, and may be traced over that muscle to become continuous with the superfi cial fascia on the back. It is the deep layer of this fascia which was described by Godman of Philadelphia* as passing downwards behind the sternum to be continuous with the fibrous pericardium. This description has been sub sequently confirmed by more than one anato mist in France, although denied by Cru veilhier, and in this country by Sir Astley Cooper,t who has described it in the same manner, apparently without being acquainted with the previously recorded statements of the anatomists above referred to; I may add that I have myself in many instances proved the accuracy of Godman's description. The cer vical fascia is continuous superiorly with the superficial fascia on the face; and inferiorly, besides tracing it into the pectoral region, we can follow it over the shoulder into the arm. The cervical fascia, in a great part of its extent, is not, as the superficial fascia elsewhere, in intimate connexion with the subcutaneous cel lular tissue, but is separated from it on each side of the neck by the fibres of the platysma myoides. From this brief account of the cervi cal fascia, (we refer for the more particular description to the article on the surgical ana tomy of the NECK,) we learn one characteristic of the superficial fascia, namely, its continuity all over the body.