. Elementary physiology . cular surface (the glenoid fossa) covered with cartilage, against which the head of the humerus^ or upper arm- bone, moves. The head of the humerus has a spherical surface, also coated with cartilage, and the joint is enclosed by a capsule, so as to make a shallow ball-and- socket joint. The scapula and its processes, together with the clavicle, give at- tachment to the muscles which move the arm at the shoulder-joint. The attachments of the sternum, shoulder-girdle, and humerus are represented in Fig. 23; it may be pointed out that there is a disc of cartilage at the
. Elementary physiology . cular surface (the glenoid fossa) covered with cartilage, against which the head of the humerus^ or upper arm- bone, moves. The head of the humerus has a spherical surface, also coated with cartilage, and the joint is enclosed by a capsule, so as to make a shallow ball-and- socket joint. The scapula and its processes, together with the clavicle, give at- tachment to the muscles which move the arm at the shoulder-joint. The attachments of the sternum, shoulder-girdle, and humerus are represented in Fig. 23; it may be pointed out that there is a disc of cartilage at the articulation between the clavicle and sternum. The humeims^ or bone of the upper arm (see Fig. 24), extends from the shoulder to the elbow; it articulates at the shoulder with the scapula, and at the elbow with the ulna and radi^Ls^ the bones of the forearm. The upper extremity of the humerus includes the head, a hemispherical articular surface which, as above described, forms part of the shoulder-joint; the neck, a narrow groove marking off the head from the rest of the bone; and the great and small tuberosities, which are eminences giving attachment to certain of the shoulder muscles. The shaft or body of the bone bears rough patches on its surface at places where muscles were attached. It is cylindrical in shape above, but triangular below. At its lower extremity the bone Fig. 22.— Dorsal view of right scapula. (Drawn by T. W. P. Lawrence.)
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Keywords: ., bookcentury1800, bookdecade1890, bookpubli, booksubjectphysiology
