NERVES – 4
The image shows a small region of a cross-sectioned nerve.
The perineurium that surrounds this nerve is evident as a compact, well-stained layer (highlighted in red after using the mouse or clicking on the image). 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 in 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 its nerve fibers are cross-sectioned. 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. As the myelin was removed dirng the histological procedure, the nerve fibers appear do be empty. More details about the nerve fibers will be seen on the next page.
Tne endoneurium is not easy to visualize as its amount is scarce. Inside the nerve, observe small portions of the endoneurium, the loose connective tissue that surrounds the nerve fibers. The endoneurium is therefore located between the nerve fibers. A few areas of endoneurium can be seen as regions stained by eosin in light pink and some of them become highlighted in blue when you place the cursor or click on the image.
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. High magnification.
