Ethmoid Bone revision notes quiz

What is the main function of the cribriform plate of the ethmoid bone?

Which of the following bones does the ethmoid bone articulate with?

What anatomical structure does the perpendicular plate of the ethmoid bone contribute to?

What are the consequences of a fracture in the cribriform plate?

Which part of the ethmoid bone is responsible for most of its bulk?

What condition can result from a fracture of the ethmoid labyrinth?

Which of the following functions is NOT attributed to the ethmoid bone?

Which of the following sinuses are associated with the ethmoid bone?

Ethmoid Bone Location & Articulations

Located within the paranasal sinuses
Articulates with cranial bones: frontal and sphenoid
Articulates with facial bones: vomer, inferior nasal conchae, nasal, maxilla, palatine, and lacrimal

Ethmoid Bone Structure

Small, unpaired bone
Contributes to the medial wall of the orbit and the middle cranial fossa
Separates the nasal cavity from the cranial cavity
Forms:
- Nasal septum
- Roof and lateral walls of the nasal cavity
- Small contribution to the floor of the anterior cranial fossa
3 Main Parts:

Cribriform Plate

Forms the roof of the nasal cavity
Perforated by numerous olfactory (smell) nerve fibres
Crista galli projects superiorly

Perpendicular Plate

Thin, quadrilateral plate of bone
Forms the superior two-thirds of the nasal septum
Descends vertically in the midline from the cribriform plate

Ethmoid Labyrinth

Large lateral masses located on either side of the perpendicular plate
Contains ethmoid air cells/ethmoid sinuses
The ethmoid sinuses help to warm and moisten inspired air

Clinical Relevance

Damage to the ethmoid bone can be caused by infection, inflammation, or facial trauma.
Fractures of the cribriform plate can cause anosmia (loss of smell)
Fractures of the ethmoid labyrinth may allow communication between the nasal cavity and orbit (orbital emphysema – crossover of fluids)
Inflammation can cause sinusitis or rhinorrhea (cerebrospinal fluid enters the nasal cavity and drains out)

This quiz explores the location, articulations, and structure of the ethmoid bone. It covers its vital role in separating the nasal and cranial cavities, as well as detailing its three main parts: the cribriform plate, perpendicular plate, and ethmoid labyrinth. Test your knowledge on this essential cranial structure.