Cranial and Facial Bones Anatomy

Skull Base & Lateral Skull: Ethmoid, Sphenoid, and Temporal Bones

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1. 📌 Essentials

• The **ethmoid bone is a light, sponge-like irregular bone forming part of the nasal cavity and orbit.
• The sphenoid bone is a central keystone connecting many skull bones, housing the pituitary in the sella turcica.
• The temporal bone forms part of the lateral skull, containing the structures of the ear and neurovascular foramina.
• Olfactory foramina in the ethmoid allow CN I passage.
• The crista galli anchors the falx cerebri.
• The sella turcica protects the pituitary gland.
• The foramina of sphenoid (rotundum, ovale, spinosum) transmit cranial nerves and vessels.
• The mastoid process contains air cells and attaches neck muscles, important in vestibular functions.
• The petrous part of temporal houses the inner ear structures and internal acoustic meatus.
• Skull bones form important boundaries for neurovascular pathways and sinuses.

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2. 🧩 Key Structures & Components