Ethmoidal spine

Anatomical feature of the sphenoid bone

Diagram of the sphenoid bone showing the ethmoidal spine.

The ethmoidal spine is a small, prominent bony projection located on the superior surface of the sphenoid bone. It serves as an important anatomical landmark in the skull, providing an articulation point for the cribriform plate of the ethmoid bone.

Anatomy

The ethmoidal spine is situated at the anterior part of the body of the sphenoid bone. It is a midline structure that projects upward, fitting into the groove of the cribriform plate. This articulation helps to stabilize the ethmoid bone and contributes to the formation of the anterior cranial fossa.

Relations

The ethmoidal spine is closely related to several important structures:

• Anteriorly, it is bordered by the frontal bone, which forms part of the roof of the nasal cavity.
• Posteriorly, it is continuous with the body of the sphenoid bone.
• Laterally, it is flanked by the lesser wings of the sphenoid, which extend to form part of the orbit.

Function

The primary function of the ethmoidal spine is to provide a stable articulation for the cribriform plate of the ethmoid bone. This articulation is crucial for maintaining the structural integrity of the anterior cranial fossa and the nasal cavity. Additionally, the ethmoidal spine plays a role in the separation of the nasal cavity from the cranial cavity, helping to protect the brain from potential infections originating in the nasal passages.

Clinical significance

In clinical practice, the ethmoidal spine is an important landmark for surgeons performing procedures involving the anterior cranial fossa or the paranasal sinuses. Its proximity to the olfactory bulb and the optic nerve makes it a critical area to navigate during surgical interventions to avoid damage to these structures.

Related pages

• Sphenoid bone
• Ethmoid bone
• Cribriform plate
• Anterior cranial fossa