Optic disk and nerve, normal

Source adult dog
Fixative not known
Stain Luxol fast blue
Notes Luxol fast blue stains myelin sheaths; notice that the nerve fibers forming the optic disk are myelinated, explaining the typical appearance of the canine disk ophthalmoscopically; the reason the nerve fiber bundles (fascicles) posterior to the lamina cribrosa are not always longitudinal is due to bending of the optic nerve during fixation so that other than longitudinal profiles occur during sectioning
See also
Legend [ - roughly delineates lamina cribrosa, D - optic disk, F - fascicle of myelinated nerve fibers
Illustration Click on image to see larger picture