EZMed Channel - Cranial Bones Lecture

Overview

• Focus on the anatomy and location of cranial bones.
• Skull consists of 22 bones: 8 cranial and 14 facial.
• Cranial bones form the cranium, protecting the brain.

Mnemonic

• Eight Osseous Parts Form the Skull
• Names of bones: Ethmoid, Occipital, Parietal, Frontal, Temporal, Sphenoid.

Ethmoid Bone

• Location: Roof of the nose, between the orbits.
• Features:
  • Separates nasal cavity from the brain.
  • Articulates with frontal and sphenoid bones.
  • Contains the ethmoid sinus.
  • Cribriform Plate: Passage for olfactory nerves.
  • Crista Galli: Attachment for brain membrane.

Occipital Bone

• Location: Back of the skull.
• Features:
  • Lambdoid Suture: Connects to parietal bones, shaped like lambda.
  • External Occipital Protuberance: Neck muscle attachment.
  • Occipital Condyles: Articulate with C1 (atlas).
  • Foramen Magnum: Passage for brainstem.

Parietal Bones

• Location: Either side of the skull.
• Surrounded by sutures:
  • Coronal Suture: Connects to frontal bone.
  • Squamous Suture: Connects to temporal bones.
  • Lambdoid Suture: Connects to occipital bone.
  • Sagittal Suture: Connects the two parietal bones.

Frontal Bone

• Location: Forehead.
• Features:
  • Forms superior aspect of orbits.
  • Supraorbital Foramen: Passage for supraorbital nerve.
  • Connected to parietal bones via coronal suture.

Temporal Bones

• Features:
  • Squamous Suture: Connects to parietal bones.
  • Zygomatic Process: Forms zygomatic arch (cheekbone).
  • Auditory Meatus: Canal to inner ear.
  • Mastoid Process: Neck muscle attachment.
  • Styloid Process: Muscle attachment for tongue and larynx.
  • Mandibular Fossa: Articulation with mandible.

Sphenoid Bone

• Articulates with all other cranial bones.
• Shape: Butterfly.
• Sella Turcica: Houses the pituitary gland.
• Features:
  • Greater wing, lesser wing, pterygoid processes, and body.

Conclusion

• Use mnemonic to remember cranial bone names.
• Further details on facial bones in another video.
• Notes available on the EasyMed blog linked in the description.