NERVES – 5
Portion of a cross-sectioned myelinated nerve.
The majority of its nerve fibers are arranged along the longitudinal axis of the nerve and are seen cross-sectioned.
Axons are the dark circles inside the fibers.
Axons of the perypheral nervous fibers are covered by folds of Schwann cell cytoplasm. The membranes of these folds the nerve shown in this page turned into a When membranes of Schwann cells turned into myelin, hence this is a myelinated nerve. Myelin is basically constituted by fat and it was dissolved and lost during the preparation of this section. For this reason the region around the axons appears empty and unstained. It is highlighted in green.
The loose connective tissue of the endoneurium is a placed between the nerve fibers but is scarce in most of the section. It is stained in light pink between nerve fibers.
The unstained, empty spaces between nerve fibers and between groups of fibers are a technical artifact, due to tissue retraction, a defect introduced during the preparation of the material.
Nerve (cross section). Staining: HE. Medium magnification.
The following figures show details of Schwann cell cytoplasm highlighted in light green, Schwann cell nucleus in dark green and axons in blue.
Nerve (cross section). Staining: HE. Medium magnification.
