Skull Base and Cranial Bones Revision Sheet

1. 📌 Essentials

• The cranium consists of ethmoid, sphenoid, temporal, and other bones that form the skull base.
• The ethmoid is unpaired, located at the anterior skull base, and contributes to nasal septum and orbit walls.
• The sphenoid is centrally located, the sella turcica which houses the pituitary gland.
• The temporal bones form the lateral skull base, housing structures for hearing and balance.
• The foramina (e.g., rotundum, ovale, spinosum) transmit major neurovascular structures.
• The optic canal is formed between the lesser and greater wings of the sphenoid.
• The mastoid process contains pneumatic air cells communicating with the middle ear.
• The pterygoid processes serve as attachment points for masticatory muscles.
• The carotid canal transmits the internal carotid artery into the skull.
• The stylomastoid foramen allows the facial nerve (CN VII) to exit the skull.

2. 🧩 Key Structures & Components