In this chapter, the author combines the established views of the
ultrastructure of the sciatic nerve as an example of a combined peripheral nerve or
bundle of nerves with newer concepts that have emerged only recently. The position
and importance of the circumneural (paraneural) sheath and subcircumneural or
subparaneural space are discussed, as well as the other membranes and
compartments around a peripheral nerve, namely, the endoneurium, perineurium,
epineurium, and epimysium. The subepimyseal space is discussed in the context of
peripheral nerve block.
Keywords: Acute pain medicine, Axon, Circumneural sheath, Combined
peripheral nerve, Continuous peripheral nerve block, Endoneurium, Epimysium,
Fascia, Fascicles, Gliding apparatus, Microanatomy, Nerve axon, Paraneural
sheath, Perineurium Epineurium, Peripheral nerve block, Regional anesthesia,
Sciatic nerve, Subcircumneural space, Subepimyseal space, Subparaneural space,
Ultrastructure.
