SCAPULAR REGION (DESCRIPTIVE AND STJRG1CAL ANATOMY OF). The term sca pular region is intended by some anatomists to comprise all the structures which lie on the scapula, on its anterior as well as on its pos terior surface; but, in accordance with the arrangement of Velpeau and others, we limit the term scapular region to the posterior as pect of the scapula, regarding its anterior, or subscapular, surface as appertaining to, and forming one of the boundaries of, the axillary region. Under the denomination then of scapular region, we include a portion of the posterior aspect of the shoulder, presenting a triangular outline, to which the following boundaries may be assigned. Its base, which is placed internally, is constituted by the ver tebral margin of the scapula; its apex, placed externally, becomes continuous with the re gion of the shoulder joint ; inferiorly, it is limited by the lower oblique edge of the la tissimus dorsi muscle, which likewise separates it froin the region of the axilla ; and above, the superior costa of the scapula constitutes its extreme boundary, and separates it from the great posterior triangle of the neck.
Between the integuments and the dorsum of the scapula, which forms the floor of the region under consideration, lie numerous muscles, layers of fascise, vascular inoscula tions, branches of nerves, &c., which we shall describe in the order in which they present themselves in dissection.
The muscles, which are nunierous, may be divided into the extrinsic and the intrinsic; the latter are, the fleshy portions only of the supra-and infra-spinati, and of the teres major and the teres minor muscles. Under the former class, we shall have to speak of portions of the trapezius, latissimus dorsi, and deltoid muscles. Numerous other muscles are at tached to the different borders of the scapular region; but these have been already described in the several articles treating of the regions to which they more properly belong (vide NECK, BACK, ARM). The projection back wards of the spine of the scapula naturally divides the scapular region into two distinct parts, terined by anatoinists the supra- and infra-spinal fossm ; and in this article we shall describe, seriatim, the anatomical relations of the structures which occupy these two fossm respectively.
The subcutaneous layer of areolar tissue, throughout the whole of the scapular region, is dense, and much more closely connected to the integument than to the aponeurosis be neath. Very free motion of the skin on the deeper seated structures is thus allowed. In this layer superiorly, we find some of the superficial descending branches of the cervical plexus of nerves passing towards the region of the shoulder, where they become lost in the integument. Beneath the skin, sub cutaneous areolar tissue, and superficial layer of fascia, the trapezius muscle covers all that portion of the scapular region which corre sponds to the supra-spinal fossa. The fibres of this muscle take a ,direction downwards, outwards, and forwards, across this region, to the upper edge of the spinous process, and angle of junction between the acromion pro cess and clavicle, into which they are inserted; the more posterior fibres are oblique ; the an terior, coming from the superior crest on the occipital bone, descend more perpendicularly. This muscle acts powerfully as an elevator of the shoulder joint, its anterior fibres drawing the entire scapula upwards and backwards, and with it the upper extremity, whilst its posterior flbres effect the sante- purpose by producing 4 motion of rotation in the scapula, in virtue of which the posterior angle of that bone is depressed, and the anterior, or acro mial extremity, proportionately elevated. Li cutting through the trapezius muscle, the anatomist will probably, meet with some of the terminal branches of the spinal accessory nerve distributed to this muscle ; as also descending branches of the supra-scapular artery, which, becoming superficial, maintain around the acromion process an anastomosis with the ascending (inferior acromial) branches of the acromial axis, and the circumflex branches of the axillarj: trunk.