Cranial Fossa

Question 1

Name the 3 cranial fossa & describe the bones that make them up

Answer 1

Anterior - frontal, ethmoid & sphenoid (lesser wing)
Middle - sphenoid, temporal, parietal
Posterior - temporal, parietal, occipital

Question 2

Describe the boundaries of the anterior cranial fossa

Answer 2

Anterior - frontal bone
Posterior - sphenoid (lesser wing)
Floor - frontal & ehtmoid

Question 3

Describe the boundaries of the middle cranial fossa

Answer 3

Anterior - sphenoid
Posterior - temporal
Floor - sphenoid & temporal

Question 4

Describe the boundaries of the posterior cranial fossa

Answer 4

Anterior - temporal
Posterior - occipital
Floor - occipital

Question 5

Describe the contents of the anterior cranial fossa

Answer 5

Frontal crest - median extension of frontal bone
Crista galli -median ridge projecting from ethmoid
Cribiform plate - of ethmoid (passage for olfactory nerves)
Anterior clinoid processes of sphenoid

Question 6

Describe the contents of the middle cranial fossa

Answer 6

Sella Turcica
Dorsum sellae
Hypophyseal fossa
Foramen ovale - for passage of CV3 (trigeminal - mandibular)
Foramen rotundum - for passage of CV2 (trigeminal - maxillae)

Question 7

Describe the contents of the posterior cranial fossa

Answer 7

Foramen magnum - for passage of spinal cord & meninges, anterior and posterior spinal arteries, vertebral artery, CN XI spinal accessory nerve

Internal Occipital Crest - posterior to foramen mangum, divides posterior fossa partially into 2 cerebellar fossae

Internal Occipital Protruberance - end of internal occipital crest