. Cunningham's Text-book of anatomy. Anatomy. 590 THE MUSCULAK SYSTEM. Biceps braci FIBROSr (by their attachment to the extensor tendons) as extensors of the fingers, acting on both inter- phalangeal joints. M. Flexor Pollicis Longus.—The flexor pollicis longus arises beneath the flexor digitorum sublimis by fleshy fibres from the volar surface of the shaft of the radius in its middle two- fourths, and from a corresponding portion of the interosseous mem- brane. It has an additional origin occasionally from the medial border of the coronoid process of the ulna (Fig. 348, p. 389). Its
. Cunningham's Text-book of anatomy. Anatomy. 590 THE MUSCULAK SYSTEM. Biceps braci FIBROSr (by their attachment to the extensor tendons) as extensors of the fingers, acting on both inter- phalangeal joints. M. Flexor Pollicis Longus.—The flexor pollicis longus arises beneath the flexor digitorum sublimis by fleshy fibres from the volar surface of the shaft of the radius in its middle two- fourths, and from a corresponding portion of the interosseous mem- brane. It has an additional origin occasionally from the medial border of the coronoid process of the ulna (Fig. 348, p. 389). Its radial origin is limited proximally by the oblique proximal part of the volar margin of the radius and the origin of the flexor digitorum sublimis, and distally by the insertion of the pronator quadratus muscle. The muscle ends proximal to the wrist in a tendon, which passes over the pronator quadratus into the hand beneath the transverse carpal ligament, enveloped in a special synovial sheath. In the palm the tendon is directed distally along the medial side of the thenar eminence, be- tween the flexor brevis and ad- ductor muscles of the thumb, to be inserted into the base of the terminal phalanx of the thumb on its palmar surface. The muscle is placed deeply in the forearm, being concealed by the superficial layer of muscles and by the flexor disitorum sublimis. Pronator teres Superficial flexor (origin) Biceps tendon TUBERCLE OF RADIUS Supinator muscle Brachioradialis Pronator teres Flexor digitorum profundus Flexor pollici. Flexor carpi ulnarls Flexor digitorum profundus (for index finger) Nerve - Supply. —Volar interosseous branch of the median (C. 7. 8. T. 1.). Actions.—The muscle is a flexor of the wrist and thumb, acting in the latter movement on the metacarpal bone and both phalanges. M. Pronator Quadratus.—The pronator quadratus is a quadri- lateral fleshy muscle, occupying the distal fourth of the forearm. It is placed beneath the deep flexor tendons, and a
Size: 912px × 2741px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1914
