cranial bones revision sheet

1. 📌 Essentials

• The ethmoid bone is unpaired, located at the anterior skull base, forming part of both the neurocranium and viscerocranium.
• The cribriform plate contains olfactory foramina, transmitting CN I.
• The perpendicular plate forms the superior part of the nasal septum and attaches to the falx cerebri.
• The sphenoid is a centrally-located butterfly-shaped bone forming part of the skull base.
• The sphenoid sinus is paired, separated by a septum; the sella turcica houses the pituitary gland.
• The temporal bone is paired, lateral, and contains the squamous, petrous, and mastoid parts.
• Foramina such as the optic canal, foramen rotundum, ovale, spinosum, jugular foramen, and carotid canal are passageways for nerves and vessels.
• The temporal bone's mastoid process contains air cells and sites for muscle attachment.
• The petrous part houses the inner ear and internal acoustic meatus.
• Key attachments include the temporalis muscle (temporal fossa) and pterygoid muscles (pterygoid processes).

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