Anatomy of the Interior of the Cranium

Overview

• Examining the interior of the cranium from a superior view.
• Removed the top of the skull to view the cranial interior.

Identification of Bones

• Frontal Bone: Located at the front, attaching to the parietal bones.
• Parietal Bones: Connect to the temporal bone.
• Temporal Bone: Includes the petrous portion visible in this view.

Foramina in the Skull

• Foramen Magnum: Large opening visible in the skull base.
• Jugular Foramen: Located bilaterally.
• Foramen Ovale: Present on both sides.
• Foramen Spinosum: Located near the foramen ovale.
• Foramen Lacerum: Situated in the cranial base.
• Foramen Rotundum: Newly added foramen, located in the sphenoid bone.
• Optic Foramen: Found in the sphenoid bone for the passage of the optic nerve.

Sphenoid Bone

• Situated at the center of the skull, resembling a butterfly.
• Sella Turcica: Depression in the sphenoid bone for the pituitary gland.
• Wings of the Sphenoid:
  • Greater Wing: Larger portion, located inferiorly.
  • Lesser Wing: Smaller portion, located superiorly.

Internal Auditory Meatus

• Located near the jugular foramen, on both sides.
• Complements the external auditory meatus.

Ethmoid Bone

• Seen in the cranial cavity, also part of the nasal cavity.
• Cribriform Plate: Flat portion with perforations for olfactory nerve endings.
• Crista Galli: Process projecting upwards, part of the ethmoid bone.

Key Structures

• Olfactory Nerve: Passes through the cribriform plate for the sense of smell.
• Pituitary Gland: Sits in the sella turcica of the sphenoid bone.