F25: A section, Azan stained, showing oblique and cross-sectioned nerve. Here the endoneurium (a) and other CT is blue. The nerve fibers with associated remains of the myelin sheath are stained red. One fascicle (b) is cut mainly in cross-section. Do not depend upon this type of well-demarcated color staining for your own diagnoses, but this slide is a good example of how difficult it is sometimes to distinguish small nerves from small bundles of smooth muscle. In this course we will not expect you to make every fine distinction possible; rather we are interested in the general principles and relatively "normal" appearances.