QUAIN'S ANATOMY.

Seventh Edition.

EDITED BY

WILLIAM SHARPEY, M.D., F.R.S.,

PROFESSOR OF ANATOMY AND PHYSIOLOGY IN UNIVERSITY COLLEGE, LONDON,

ALLEN THOMSON, M.D., F.R.S.,

PROFESSOR OF ANATOMY IN THE UNIVERSITY OF GLASGOW.

AND

JOHN CLELAND, M.D.,

PROFESSOR OF ANATOMY IN QUEEN'S COLLEGE, GALWAY.

PART III.

CONTAINING

THE DESCRIPTIVE ANATOMY OF THE ORGANS OF SENSE AND
VISCERA, WITH SURGICAL ANATOMY, DISSECTIONS, AND
THE CONCLUSION OF THE GENERAL ANATOMY.

•BOD!

In Binding,

TO THE BINDER.

Vol. I. is to contain

GENERAL ANATOMY, pp. i. to ccxxvii..

DESCRIPTIVE ANATOMY, pp. 1 to 500, with the addition of the four pages 501* to 504*, contained in this Part.

Vol. II. is to contain

DESCRIPTIVE ANATOMY, &c., and INDEX, pp. 501 to 1147. A cancel for Vol. I. pp. 225, 226, is given in this Part.

MUSCLES OF THE HAND.

225

the common extensor through a compartment of the annular ligament, comes in contact with the tendon from that muscle destined for the index finger, and unites with it to form the expansion already described.

Fig. 185.-TRANSVERSE SECTION OF THE RIGHT
HAND BETWEEN THE CARPUS AND META-
CARPUS, SHOWING THE ANTERIOR ANNULAR
LIGAMENT OF THE CARPUS, AND THE PLACES
OF THE VARIOUS EXTENSOR AND FLEXOR
TENDONS, SEEN FROM THE DISTAL SIDE. 호

Fig. 185.

This figure is also designed to show the transverse arch formed by the second row of carpal bones. a, metacarpal articular surface of the trapezium for the metacarpal bone of the thumb; a', palmar ridge of the trapezium; b, articular surface of the trapezoid bone for the second metacarpal bone; c, the surface of the os magnum for the middle metacarpal ; d, the surface of the unciform for the fourth, and e, that for the fifth metacarpa bone; e', unciform process; between a' and e, the cut edge of the annular ligament is represented, the ends attached to the projecting parts of these bones, and sending another process towards the trapezium at 11, by which the tendon of the flexor carpi radialis is enclosed in the groove of the trapezium; 1, tendon of extensor ossis metacarpi pollicis; 2, extensor primi internodii; 3, extensor secundi internodii; 4, extensor indicis; 5 and 6, long and short radial extensors of the carpus; 7, the four divisions of the tendon of the common extensor of the fingers, the middle two belong to the third and fourth fingers; 8, extensor minimi digiti; 9, extensor carpi ulnaris; 10, flexor carpi radialis; 11, flexor longus pollicis; 12, the first on the ulnar side of the tendons of the flexor superficialis digitorum; 13, the same of the flexor profundus; 14, the median nerve; 15, points to the middle of the cut margin of the palmar aponeurosis stretched across the annular ligament; 16, the fibres of the palmaris brevis muscle; 17, cut surface of the muscles of the ball of the thumb; 18, muscles of the little finger.

MUSCLES OF THE HAND.

Besides the tendons of the long muscles and the lumbricales already described, there are placed in the hand one superficial muscle called palmaris brevis, the short muscles of the thumb and little finger, and the interossei muscles.

The palmaris brevis is a thin flat subcutaneous muscle, which arises from the inner margin of the palmar fascia and annular ligament; its fibres proceed transversely inwards, and are inserted into the skin along the inner border of the palm.

The palmaris brevis crosses the muscles of the little finger and covers the ulnar artery and nerve. It is subject to considerable variation in its breadth and thickness, consisting sometimes of only a few scattered fibres.

MUSCLES OF THE THUMB.-The fleshy mass which forms the thenar prominence, or ball of the thumb, consists of four muscles.

The abductor pollicis (abductor brevis pollicis,-Alb.), superficial and flat, arises from the annular ligament and from the ridge of the os trapezium, and, proceeding outwards and forwards, is inserted by a tendon into the radial border of the first phalanx of the thumb at its base.

The opponens pollicis, placed behind the abductor, arises from the annular ligament and from the os trapezium and its ridge, and is inserted intothe whole length of the metacarpal bone of the thumb at the radial border.

The flexor brevis pollicis arises by two heads, a superficial and à deep. The superficial head is attached to the outer two-thirds of the annular

Fig. 186.-MUSCLES AND TENDONS OF THE

PALMAR ASPECT OF THE HAND.

A portion of the tendons of the superficial flexor has been cut away to show those of the deep flexor and the lumbricales. 1, tendon of the flexor carpi radialis, cut short near the place where it enters the canal in the outer attachment of the annular ligament of the carpus; 2, tendon of the flexor carpi ulnaris, inserted into the pisiform bone; 3, anterior annular ligament of the carpus; 4, abductor pollicis; 5, opponens pollicis; 6, 6, flexor brevis; 7, adductor pollicis; 8, abductor minimi digiti; 9, flexor brevis minimi digiti; 10, lumbricales, passing to their insertion on the radial side of the four fingers.

ligament and to the os magnum : the deep head is attached to the os trapezoides and os magnum, to the sheath of the flexor carpi radialis and to the bases of the second and third metacarpal bones. From the superficial and deep heads of origin two strong masses of fibres which, becoming tendinous, are attached to the outer and inner sesamoid bones respectively, and are inserted into the sides of the base of the first phalanx of the thumb; the outer head is also joined by a considerable fasciculus from the deeper origin; the inner head is inserted conjointly with the adductor pollicis. The two tendons of insertion, with the sesa

Fig. 187.-DEEP MUSCLES OF THE PALM OF
THE HAND.

The abductor pollicis and abductor minimi digiti, together with the anterior annular ligament and the long flexor tendons in the palm, have been removed; in the forefinger the tendons of both the superficial and deep flexors remain; in the other fingers the tendons of the superficial flexor have been removed. 1, pronator quadratus muscle; 2, opponens pollicis; 3, flexor brevis pollicis ; 4, adductor pollicis; 5, opponens minimi digiti; 6, unciform bone; 7, 8, interosseous muscles.

moid bones, play over the grooved surfaces of the first metacarpal bone. The tendon of the long flexor lies between the heads of origin, and grooves the surface of the muscle as it passes between the tendons of insertion.

The adductor pollicis arises from the anterior two-thirds of the palmar surface of the metacarpal bone of the middle finger, and is inserted into the

QUAIN'S ANATOMY.