tendinous sheath of flexor pollicis longus muscle

tendinous sheath of flex·or pol·li·cis lon·gus mus·cle

[TA] the palmar carpal synovial tendon sheath that envelops the tendon of the flexor pollicis longus in its course through the carpal canal; it is continuous with the digital sheath of the thumb, the two generally being considered as one sheath. Synonym(s): vagina tendinis musculi flexoris pollicis longi [TA], radial bursa