Cribriform plate of the ethmoid
Exit foramen · CN I
The perforated plate in the floor of the anterior cranial fossa through which some twenty olfactory fascicles pass up from the nasal roof to the olfactory bulb, accompanied by the anterior ethmoidal nerve and vessels. It is thin and fractures easily with frontal impacts.
Traced from the start
- Forebrain (telencephalon and diencephalon)
- Olfactory nerve (CN I)
- Cribriform plate of the ethmoid
Detail
- Transmits
- Olfactory nerve fascicles (CN I), anterior ethmoidal nerve (V1) and vessels
- Bone
- Ethmoid; forms the roof of the nasal cavity and the medial floor of the anterior cranial fossa
When it goes wrong
Anterior skull base fracture through the cribriform plate
Anosmia with clear CSF rhinorrhoea (beta-2 transferrin positive), risk of meningitis and pneumocephalus; nasogastric tubes are contraindicated until the base of skull is cleared
Practise this structure
4 questions in the bank tagged Cranial Nerves.
A 52-year-old woman has had two months of numbness over the right forehead, the right upper eyelid and the tip of her nose, with a gritty feeling in the right e…
Foundations · middle twist
A 44-year-old man has had 18 months of worsening hearing on the left with constant ringing in that ear. He still follows conversation in a quiet room but cannot…
Foundations · middle twist
A 58-year-old man has sudden vertigo and a hoarse voice, and chokes when he drinks. The palate elevates to the right and there is no gag response when the left…
Foundations · middle twist
A 27-year-old man was struck on the head at football a week ago. He now sees two images, one above the other, worst when reading or going down stairs. The verti…
Foundations · middle twist