The<unk>  is composed of connective tissue, which has a distinctly lamellar arrangement consisting of one to several concentric layers. The<unk>  is composed of perineurial cells, which are epithelioid myofibroblasts. Perineurial cells are sometimes referred to as myoepithelioid due to their epithelioid and myofibroblastoid properties including tight junctions, gap junctions, external laminae and contractility. The tight junctions provide selective barrier to chemical substances. The<unk>  is a smooth, transparent tubular membrane which may be easily separated from the fibers it encloses. In contrast, the epineurium is a tough and mechanically resistant tissue which is not easily penetrated by a needle.
Perineurium
Tetracaine
Procaine
Tetrodocain
Iontocaine
Ibogaine
Methitural
Mivacurium chloride