Flexor tendons, common flexor sheath, fibrous digital sheaths, and synovial sheaths of the digits

Dissection of the palm of the hand illustrating the tendons and fibrous digital tendon sheaths. The fibrous sheaths of the digits are strong coverings of the flexor tendons, which extend from the heads of the metacarpals to the base of the distal phalanges. They prevent the tendons from pulling away from the bones of the digits. They attach along the borders of the proximal and middle phalanges, to capsules of the interphalangeal joints, and to the surface of the distal phalanx.