. The anatomy of the human body. Human anatomy; Anatomy. 258 MYOLOGY. ders any such independent action as difficult as in the other fingers, and much more so than in the index finger. The Extensor Carpi Ulnaris. The extemor carpi ulnaris (e, Jig. 121), the most superficial and the most internal* of the muscles on the back of the forearm, arises from the external tuberosity of the humerus ; from the posterior surface of the ulna, which is a little excavated for this purpose ; from the middle third of the posterior border of that bone ; and from the anterior surface of an aponeurosis covering th
. The anatomy of the human body. Human anatomy; Anatomy. 258 MYOLOGY. ders any such independent action as difficult as in the other fingers, and much more so than in the index finger. The Extensor Carpi Ulnaris. The extemor carpi ulnaris (e, Jig. 121), the most superficial and the most internal* of the muscles on the back of the forearm, arises from the external tuberosity of the humerus ; from the posterior surface of the ulna, which is a little excavated for this purpose ; from the middle third of the posterior border of that bone ; and from the anterior surface of an aponeurosis covering the muscle behind. It is inserted behind the upper end of the fifth metacarpal bone. Its origin is effected by means of a fibrous pyramid, the apex of which is attached to the outer tuberosity of the humerus. From the interior of this pyr- amid, and from the other origins above mentioned, the fleshy fibres proceed to a tendon, which, by a very uncommon arrangement, extends through the substance of the muscle, even from its superior attachment, without commencing in the form of an aponeurosis. At the lower third of the forearm, this tendon appears on the posterior border of the then semi-penniform muscle, and continues to receive fleshy fibres on its anterior edge until it enters the groove intended for it on the ulna. This oblique groove is continued as far Fig. 132. as the insertion of the tendon into the metacarpal bone, by means of a long, fibrous sheath, and is lined throughout by a synovial membrane. Relations.—The extensor carpi ulnaris is covered by the fascia of the forearm: it covers the ulna, the supinator brevis, and the mus- cles of the deep layer. Action.—It extends the second row of the carpus upon the first, and this upon the forearm. It is, at the same time, an adductor of the ,g hand, which it inclines towards the ulnar border of the forearm. The Anconeus. The anconeus (brevis anconeus, Eustachius; le petit ancone, Wins- low, g, Jigs. 121, 122) is a short, tr
Size: 830px × 3011px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookcentury1800, booksubjectanatomy, booksubjecthumananatomy
