Quick-frozen deep-etched preparation of skeletal muscle tissue shows the muscle fiber and associated extracellular components. The basement membrane (labeled basal lamina) lies adjacent to the undulat...

Electron micrograph of a nerve from the mesentery of a rat shows groups of unmyelinated axons wrapped by deeply invaginating Schwann cells in cross section. Surrounding the Schwann cell wrapping is a ...

Sarcolemma of skeletal muscle prepared by a quick-freeze deep-etch method also shows the basement membrane (lamina externa, labeled here as the basal lamina) associated with the muscle fiber. This me...

Schwann cells in peripheral nerves secrete a layer similar to the basal lamina called the lamina externa, boundary layer, or basement membrane. In this micrograph, the lamina externa surrounds the Sc...