A 32-year-old man presents with unilateral anosmia following a head injury. Fracture of which bone is most likely responsible?

• A Frontal bone
• B Temporal bone (petrous part)
• C Sphenoid bone (lesser wing)
• D Ethmoid bone (cribriform plate) ✓

Explanation

The cribriform plate of the ethmoid bone transmits olfactory nerve filaments from the nasal mucosa to the olfactory bulb. Fracture here shears these filaments causing anosmia, and also risks CSF rhinorrhea. The petrous temporal bone fracture causes CSF otorrhea or facial nerve palsy. Frontal bone fractures do not typically affect olfaction unless extending posteriorly to the cribriform region.

Reference: Gray's Anatomy, 42nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.