neurolemma

Each branch receives tubular sheaths from the dura mater and pia mater, the former being lost in the periosteum of the nose, the latter in the neurolemma of the nerve.

IX. Neurology. 5a. The Olfactory Nerves 1918

When the nerve fiber approaches its termination, the medullary sheath suddenly disappears, leaving only the axis-cylinder surrounded by the neurolemma.

X. The Organs of the Senses and the Common Integument. 1e. Peripheral Terminations of Nerves of General Sensations 1918

The neurolemma or primitive sheath is not interrupted at the nodes, but passes over them as a continuous membrane.

IX. Neurology. 1. Structure of the Nervous System 1918

The neurolemma or primitive sheath presents the appearance of a delicate, structureless membrane.

IX. Neurology. 1. Structure of the Nervous System 1918

The axis-cylinder is the essential part of the nerve fiber, and is always present; the medullary sheath and the neurolemma are occasionally absent, expecially at the origin and termination of the nerve fiber.

IX. Neurology. 1. Structure of the Nervous System 1918

The central portion is named the axis-cylinder; around this is a sheath of fatty material, staining black with osmic acid, named the white substance of Schwann or medullary sheath, which gives to the fiber its double contour, and the whole is enclosed in a delicate membrane, the neurolemma, primitive sheath, or nucleated sheath of Schwann (Fig. 633) 12

IX. Neurology. 1. Structure of the Nervous System 1918

The nerve fiber, on approaching the muscular fiber, suddenly loses its medullary sheath, the neurolemma becomes continuous with the sarcolemma of the muscle, and only the axis-cylinder enters the muscular fiber.

IX. Neurology. 1. Structure of the Nervous System 1918

These nuclei are believed to be in connection with a delicate sheath corresponding with the neurolemma of the medullated nerve fiber.

IX. Neurology. 1. Structure of the Nervous System 1918

If the fiber be treated with silver nitrate the reagent penetrates the neurolemma at the nodes, and on exposure to light reduction takes place, giving rise to the appearance of black crosses, Ranvier’s crosses, on the axis-cylinder.

IX. Neurology. 1. Structure of the Nervous System 1918

Each nerve cell has a nucleated sheath which is continuous with the neurolemma of the nerve fiber with which the cell is connected.

IX. Neurology. 1. Structure of the Nervous System 1918