NERVES – 4
The image shows a small region of a cross-section of a nerve.
The perineurium surrounding this nerve is clearly evident as a compact, well-stained layer. The nuclei of the perineurium cells are fusiform and have dense, well-stained chromatin.
The interior of the nerve consists almost entirely of nerve fibers. They are arranged parallel to each other and along the major axis (longitudinal axis) of the nerve. As this is a cross-section of the nerve, most of the nerve fibers are seen sectioned transversely. They are the small pink circles that occupy most of the interior of the nerve. Six fibers are highlighted by green circles after using the mouse or clicking on the figure. All or almost all fibers of this nerve are myelinated fibers. More details about the nerve fibers will be seen on the next page.
Inside the nerve, small portions of the endoneurium, the loose connective tissue that surrounds the nerve fibers, can be seen. The endoneurium is therefore located between the nerve fibers. Its quantity is scarce and it is not easy to visualize. They are the portions stained light pink between the fibers. Some sections of endoneurium are highlighted in blue when you place the cursor or click on the image.
The white, 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. High magnification.
