| flexor pollicis brevis | <anatomy, muscle> Origin, superficial portion from flexor retinaculum of wrist, deep portion from ulnar side of first metacarpal bone; insertion, base of proximal phalanx of thumb; action, flexes proximal phalanx of thumb; nerve supply, median (superficial head) and deep branch of ulnar (deep head). Some authors consider the deep head to be the first in a series of four palmar interossei muscles of the hand. Synonym: musculus flexor pollicis brevis, short flexor muscle of thumb. (05 Mar 2000) |
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| flexor pollicis longus | <anatomy, muscle> Origin, anterior surface of middle third of radius; insertion, distal phalanx of thumb; action, flexes distal phalanx of thumb; nerve supply, median palmar interosseous. Synonym: musculus flexor pollicis longus, long flexor muscle of thumb, musculus flexor longus pollicis. (05 Mar 2000) |