Henry Gray (18251861). Anatomy of the Human Body. 1918.
Herbst has described a nerve-ending somewhat similar to the Pacinian corpuscle, in the mucous membrane of the tongue of the duck, and in some other situations. It differs, however, from the Pacinian corpuscle, in being smaller, in its capsules being more closely approximated, and especially in the act that the axis-cylinder in the central clear space is coated with a continuous row of nuclei. These bodies are known as the corpuscles of Herbst.
The corpuscles of Golgi and Mazzoni are found in the subcutaneous tissue of the pulp of the fingers. They differ from Pacinian corpuscles in that their capsules are thinner, their contained cores thicker, and in the latter the axis-cylinders ramify more extensively and end in flat expansions.
The tactile corpuscles of Wagner and Meissner(Fig. 936) are oval-shaped bodies. Each is enveloped by a connective-tissue capsule, and imperfect membranous septa derived from this penetrate the interior. The axis-cylinder passes through the capsule, and after making several spiral turns around the body of the corpuscle ends in small globular or pyriform enlargements. These tactile corpuscles occur in the papillæ of the corium of the hand and foot, the front of the forearm, the skin of the lips, the mucous membrane of the tip of the tongue, the palpebral conjunctiva, and the skin of the mammary papilla.
Corpuscles of Ruffini.Ruffini described a special variety of nerve-ending in the subcutaneous tissue of the human finger (Fig. 937); they are principally situated at the junction of the corium with the subcutaneous tissue. They are oval in shape, and consist of strong connective-tissue sheaths, inside which the nerve fibers divide into numerous branches, which show varicosities and end in small free knobs.
The neurotendinous spindles (organs of Golgi) are chiefly found near the junctions of tendons and muscles. Each is enclosed in a capsule which contains a number of enlarged tendon fasciculi (intrafusal fasciculi). One or more nerve fibers perforate the side of the capsule and lose their medullary sheaths; the axis-cylinders subdivide and end between the tendon fibers in irregular disks or varicosities (Fig. 938).
FIG. 938 Organ of Golgi (neurotendinous spindle) from the human tendo calcaneus. (After Ciaccio.) (See enlarged image)
The neuromuscular spindles are present in the majority of voluntary muscles, and consist of small bundles of peculiar muscular fibers (intrafusal fibers), embryonic in type, invested by capsules, within which nerve fibers, experimentally shown to be sensory in origin, terminate. These neuromuscular spindles vary in length from 0.8 mm. to 5 mm., and have a distinctly fusiform appearance. The large medullated nerve fibers passing to the end-organ are from