Muscles and regions of the neck / by John Simon.

  • Simon, Sir John, 1816-1904.
Date:
1843
Catalogue details

Licence: Public Domain Mark

Credit: Muscles and regions of the neck / by John Simon. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    the prolongation which it sends downward on the scaleni; and which partly fixes itself to tlie rib around the attachments of those muscles, partly extends itself, as a strong infundibulum on the brachial plexus and subclavian vessels. I'rom this—their fascial sheath—an horizontal slip detaches itself and passes forward to tlie pos- terior surface of the clavicle, where it fixes itself by two laminje; the upper of these is inserted just above the attachment of the sub- clavius muscle, while the lower is continued into the sheath which that muscle derives from the coraco-costal fascia. I’he horizontal pro- cess separates the cavity of the axilla from the lower triangle of the neck, and the vaginal prolongation, contracting as it descends, be- comes lost in the sheath of the axillary vessels. Finally, as these various layers of fascia at- tach themselves about the inlet of the thorax, (the sub-hyoid part of the cervical aponeurosis in front, and the pre-vertebral behind,) they are connected to one another and to the large vascular and mucous canals, which traverse that passage, by certain horizontal processes of fibrous membrane, which constitute together a kind of diaphragm, or cervico-thoracic septum. Viewed from below this would seem a vaulted membrane, oveiurchiug the tops of the pleu- rae, and giving infundibular passage to the great arterial and venous trunks and to the trachea; viewed from above it would present the various deep implantations of the cervical fascia, and a surface without aperture or breach of continuity, prolonging itself in several di- rections round the canals, which it thus indi- rectly transmits. The obvious use of these ar- rangements is to supply adequate resistance to the atmospheric pressure, which, were it not borne off by the tension of these fasciae, would at each inspiratory effort tend to flatten the trachea, or to rush through the upper strait of the thorax. Allan Burns, who in this country first drew attention to the importance of the cervical fascia, carefully illustrates its func- tions in health, and the inconveniences which accompany its destruction. (Op. cit.) III.—Regional distribution and sur- gical ANATOMY of the NECK. The posterior parts of the neck having been described in a previous article (see Back), the present will be restricted to an account of its anterior aspect. The cervical vertebrae (by their bodies, inter- vening fibro-cartilaginous discs, and transverse processes), together with the anterior and la- teral vertebral muscles, already described, com- pose the skeleton and supporting fabric of this region; the anterior fibres of the trapezii, as they descend on either side to the inner edge of the acromio-clavicular arch, form its lateral boundaries; the larynx and trachea (covered by their own extrinsic riband-like muscles, and partly covering the pharynx and oesophagus) separate the nearly symmetrical halves of the neck by constituting along its median line a marked columnar relief, in the recesses beside which lie the great cervical vessels; the base of the skull and the oblique line of the jaw are the upper limits of the region; the clavicle (just behind which the great vascular and ner- vous trunks of the upper extremity course) bounds it below; the skin, the plalysma myoides (in its cellular covering), and the cer- vical aponeurosis are stretched across it as ge- neral investments; while the last-named fascia ensheathes the various parts by special pro- cesses from its deeper surface. Thus, in general terms, the structure of the neck may be described; but, for the more pre- cise and particular account, which the impor- tance of its anatomy renders necessary, a division of it into spaces of small extent is convenient. The arrangement, which 1 propose following, differs but little from that usually adopted, and, perhaps, somewhat exceeds it in precision. The upper limits of the neck having been stated as the oblique line of the jaw and the base of the skull (which parts, as we shall pre- sently see, are brought into relation by the attachments of the constrictor pharyngis supe- rior), our highest region has in that direction these parts for its boundary, and extends below as far as the curve of the muscle, from which it is named the digastric space. A small space that can hardly be referreil to the digastric,—from which it is separated by the vaginal process of the temporal bone, and by attachments of fascia,—and which, from the im- portance of its contents, deserves careful consi- deration, is the posterior phari/ageul; it lies closely beneath the base of the skull, (from the vaginal process to the median line) between the pharynx and spine, and includes the carotid, jugular, and condylic canals, and the organs traversing them. If now an oblique line be carried across the neck, from the sterno-clavicular articulation to the tip of the mastoid process, it divides, as a diagonal, the remaining quadrilateral surface of the neck into two triangles; an anterior one having its apex at the sterno-clavicular joint, and its base along the posterior belly of the digastric muscle; a posterior one, having, its base at the inner two-thirds of the cla- vicle,—its apex at the mastoid process,—its posterior side formed by the trapezius,—its an- terior border defined by the imaginary line which demarks it from the anterior triangle. The omo-hyoid muscle, in its reflected course, crosses both these triangles, subdividing them ; and since the angle of its bend falls just on the line of their separation, and since it proceeds from behind the outer third of the clavicle to the body of the hyoid bone, it acts as a second diagonal in the neck, dividing each into an upper and a lower triangular space. Tliese four triangles will be described in detail; and since the sterno-mastoid (which is loo suli- stantial to be treated as a mere boundary-line) enters into all of them, and has to parts of each relations of the exfemest practical importance, some separate, chiefly recapitulatory, consi- deration will be given to its relative anatomy. Finally, to ensure for the oryansof tlie median line the consideration they require (the useful- ness of which mainly depends on their being
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