Internal Cranial Fossa

Question 1

What is the cranial. Fossa composed. Of?

Answer 1

• Composed of:
• Frontal, ethmoid, sphenoid, temporal, parietal, occipital bones
• 3 Fossae

• Anterior, middle, posterior

Question 2

What is the anterior cranial fossa composed of?

Answer 2

• Composed of:
• Frontal, ethmoid, sphenoid
• Crista galli, anterior clinoid processes, lesser wing of sphenoid
• Cribiform plate - CN I

Question 3

What is the middle cranial fossa composed of?

Answer 3

• Composed of:
• Sphenoid, temporal, parietal
  • Optic canal – CN II, ophthalmic artery
  • Superior orbital fissure (SOF) – CN III, IV, VI, V1
  • Foramen rotundum – CN V2
  • Foramen ovale – CN V3
• Foramen lacerum

• Foramen spinosum – middle meningeal
artery

• Sella turcica – pituitary gland
• Carotid canal - internal carotid artery

Question 4

What is the posterior cranial fossa composed of?

Answer 4

• Composed of:
• Occipital, temporal, sphenoid, parietal
• Internal acoustic meatus – CN VII, VIII
• Jugular foramen – CN IX, X, XI
• Hypoglossal canal – CN XII, internal
jugular vein
• Foramen magnum - Vertebral arteries, brainstem