A patient with Guillain-Barré syndrome has inflammation disrupting the blood-nerve barrier. Which specific layer of the peripheral nerve connective tissue sheath is primarily responsible for forming this barrier?
- A Endoneurium
- B Perineurium ✓
- C Epineurium
- D Mesoneurium
Correct answer: B. Perineurium
Explanation
The perineurium consists of concentric layers of flattened cells with tight junctions, forming the blood-nerve barrier that maintains the endoneurial fluid environment. The endoneurium surrounds individual axons, and the epineurium is the outermost loose connective tissue sheath. The mesoneurium is a supporting fold of connective tissue, not a barrier.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.