Volume 1

Practical anatomy : a manual of dissections / by Christopher Heath.

  • Heath, Christopher, 1835-1905.
Date:
1888
Catalogue details

Licence: Public Domain Mark

Credit: Practical anatomy : a manual of dissections / by Christopher Heath. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

    134/650 (page 50)
    or supinators, and will be found in the following order, beginning bom the radial side :—1, supinator longus; 2, extensor carpi radialis longior ; 3, extensor carpi radialis brevior ; 4, extensor communis digitorum; 5, extensor minimi digiti; 6, extensor carpi ulnaris ; there are also two small muscles attached to the bone and not seen at present, viz., 7, anconeus (covered by deep fascia), and 8, supinator brevis (under cover of the long muscles). Arising from the bones of the fore-arm alone and appearing from beneath the extensor communis digitorum, will be found four short extensor muscles which hold the following position to one another from the radial side 1, extensor ossis metacarpi pollicis ; 2, extensor primi in- ternodii pollicis ; 3, extensor secundi internodii pollicis ; 4, extensor indicis. All the eight muscles attached to the humerus have additional origins from the fascia of the arm or from intermuscular septa derived from it; and two, viz., the extensor carpi idnaris and supinator brevis, have additional origins from the ulna. The Supinator Radii Longus (Fig. 19, 4) is a long, narrow muscle, and has been already seen in great part in the dissections of the bend of the elbow and fore-arm. It arises from the upper two- thirds of the ridge leading to the outer condyle of the humerus and from the external intermuscular septum of the arm, which separates it from the triceps ; and is inserted into the base of the styloid process of the radius, its tendon being crossed by two short extensors of the thumb at the annular ligament. It is supplied by a special branch of the musculo-spiral nerve, and its action is that of a feeble supinator and powerful flexor of the fore-arm, when the hand is midway be- tween pronation and supination. The Extensor Carpi Radialis Longior (Fig. 19, 5) arises from the lower third of the ridge leading to the external condyle and from the external intermuscular septum ; its tendon passes beneath the two extensors of the thumb and through the second division of the annular ligament, and having then been crossed by the tendon of the third extensor of the thumb, is inserted into the base of the metacarpal bone of the fore-finger (2nd metacarpal bone). The Extensor Carpi Radialis Brevior (Fig. 19, 6), which is beneath the longer extensor, arises from the outer condyle of the humerus; from the surface of the external lateral ligament; from the fascia of the fore-arm and from the intermuscular septum between it and the extensor digitorum. Its tendon passes, with that of the long extensor, beneath the two extensors of the thumb and through