Flashcards: Cranial Bones: Ethmoid, Sphenoid, Temporal — 10 cards

What are the main cranial bones covered in this unit and their general locations?

The main bones are the Ethmoid (anterior, unpaired, forming part of the skull base, nasal septum, and orbit walls), Sphenoid (medial skull base, articulating with all neurocranial bones), and Temporal (lateral skull, protecting auditory and vestibular organs).

Ethmoid bone — role?

Part of nasal septum and orbit walls.

What are the main features and foramina of the sphenoid bone?

The sphenoid has a body with sphenoidal sinuses, lesser and greater wings forming cranial fossae and orbit walls, and pterygoid processes. Important foramina include rotundum (V2), ovale (V3), and spinosum (middle meningeal artery) for nerve and vessel passage, and the optic canal transmitting CN II and the ophthalmic artery.

Sphenoid bone — location?

Central skull base, articulates with all cranial bones.

Describe the key features of the ethmoid bone and its clinical significance.

The ethmoid is an unpaired anterior skull base bone with the cribriform plate for olfactory nerves and the perpendicular plate forming part of the nasal septum. Its lateral masses house ethmoidal sinuses and contribute to the medial walls of the orbit. It is crucial for the sense of smell and nasal structure.

Temporal bone — main parts?

Squamous, mastoid, petrous parts.

Cribriform plate — function?

Passage for olfactory nerves (CN I).

Optic canal — contents?

CN II and ophthalmic artery.

Sella turcica — location?

In sphenoid bone, holds pituitary gland.

Temporal squama — function?

Muscle attachment for temporalis.