Head and Neck Anatomy - Foramina of Skull Bones

Introduction

• Foramen: Opening allowing vital structures to pass between body parts.
• Foramina: Plural of foramen.

Foramina of Skull Bones

Frontal Bone

• Supraorbital Foramen: Located above the orbit
  • Transmits: Supraorbital nerve, artery, and vein
  • Part of V1 (first division of cranial nerve V/trigeminal nerve)

Maxilla

• Infraorbital Foramen: Located below the orbit
  • Transmits: Infraorbital nerve, artery, and vein
  • Part of V2 (second division of cranial nerve V)

Mandible

• Mental Foramen: Located on the mandible
  • Transmits: Mental nerve, artery, and vein
  • Part of V3 (third division of cranial nerve V)
• Trend: Foramina fall in a vertical line through the pupil, covering different thirds of the face for sensory innervation.

Ethmoid Bone

• Cribriform Plate: Located at the base of the skull (aerial view)
  • Contains tiny holes for tendrils of cranial nerve I (olfactory nerve)
  • Memory Aid: Baby's crib smells bad (association with olfaction/smell)

Sphenoid Bone

• Optic Canal: Transmits optic nerve (sight) and ophthalmic artery
  • Opening: Optic foramen
  • Tunnel: Optic canal
• Superior Orbital Fissure: Large opening
  • Transmits: Cranial nerves III, IV, V1, VI
• Foramen Rotundum: Round hole
  • Transmits: V2
• Foramen Ovale: Oval-shaped hole
  • Transmits: V3, lesser petrosal nerve
• Foramen Spinosum: Small hole
  • Transmits: Middle meningeal artery
• Foramen Lacerum: Hole between sphenoid, temporal, and occipital bones
  • Transmits: Greater and deep petrosal nerves (combined: Vidian nerve)
• Memory Aid: Standing Room Only (SRO)
  • S: Superior Orbital Fissure (V1)
  • R: Foramen Rotundum (V2)
  • O: Foramen Ovale (V3)

Temporal Bone

• Carotid Canal: Located near inferior part of the skull
  • Transmits: Internal carotid artery
• Internal Auditory Meatus: Transmits cranial nerves VII and VIII
• Jugular Foramen: Transmits cranial nerves IX, X, XI

Occipital Bone

• Hypoglossal Canal: Transmits cranial nerve XII
• Foramen Magnum: Large hole
  • Transmits: Spinal cord, spinal and vertebral arteries