Label A corresponds to which structure?

Label A corresponds to which structure?

• A. Epineurium
• B. Perineurium
• C. Peripheral nerve
• D. Nodes of Ranvier

Answer: (A)

The outermost covering of a peripheral nerve is the epineurium. It’s a dense connective tissue sheath that bundles several nerve fascicles together and contains blood vessels supplying the nerve. Inside this layer are the fascicles, each wrapped by the perineurium, and within those fascicles are individual axons with their own endoneurial surrounds. The nodes of Ranvier are gaps along the myelinated segments of axons, not a nerve-wide sheath. So the label on the outermost layer correctly identifies the epineurium.

The outermost covering of a peripheral nerve is the epineurium. It’s a dense connective tissue sheath that bundles several nerve fascicles together and contains blood vessels supplying the nerve. Inside this layer are the fascicles, each wrapped by the perineurium, and within those fascicles are individual axons with their own endoneurial surrounds. The nodes of Ranvier are gaps along the myelinated segments of axons, not a nerve-wide sheath. So the label on the outermost layer correctly identifies the epineurium.