Node

A knot or protuberance; an oblong, indurated swelling or tumor that forms upon bones in some forms of periostitis and osteitis. Ns., Heberden's, overgrowths of the natural tubercles of the digital phalangeal bones in rheumatoid arthritis. Ns., Parrot's, bo es of bone on the outer table of the skull, the result of syphilitic periostitis. Ns., Ranvier's, certain constrictions occurring in the course of medullated nerve-fibers, so that the sheath of Schwann lies upon the axis-cylinder. The part of the nerve between the nodes is called an inter annular or internodal segment. See Nerve-fiber. Ns., Schmidt's, a term for the medullated inter annular segments of a nerve fiber. N., Syphilitic, the localized swellings on bones due to syphilitic periostitis.