3.4 The Floor of the Skull Flashcards
What is the Floor of the Skull?
The Part of the Skull which is Visible when you remove the Skull Cap and look into the Calvarium
What are the 3 Fossae the Floor of the Skull is divided into?
- The Anterior Cranial Fossa
- The Middle Cranial Fossa
- The Posterior Cranial Fossa
What is present on the Floor of the Skull?
- Many Foramina which Nerves / Blood Vessels can Enter / Leave the Cranium
- Grooves / Depressions which indicate the position of blood vessels and other structures
Which bone forms the border of the Anterior to Middle Cranial Fossa?
The Sphenoid Bone:
a) The Lesser Wings of the Sphenoid Bone
b) The Limbus of the Sphenoid Bone
Which Bones form the floor of the Anterior Fossa contain?
- The Frontal Bone
- The Ethmoid Bone (Cribriform Plate and Crista Galli)
- The Sphenoid Bone (Lesser Wing and Limbus)
Which Bones form the floor of the Anterior Fossa contain?
- The Greater Wing of the Sphenoid
- The Petrous Part of the Temporal Bone
- The Squamous Part of the Temporal Bone
Which bone forms the border of the Middle to Posterior Cranial Fossa?
Laterally - The Petrous Part of the Temporal Bone
Medially - The Dorsum Sallae of the Sphenoid Bone
What is the Pterion?
A “H” Shaped suture of 4 Bones:
- Frontal Bone
- Parietal Bone
- Temporal Bone
- Sphenoid Bone
What structures pass through the small Foramina of the Skull?
Cranial Nerves
What is the name of the Foramen in the Anterior Cranial Fossa?
The Foramina of the Cribriform Plate (of the Ethmoid Bone)
What structure(s) pass through the Foramina of the Cribriform Plate?
Olfactory Nerves (Cranial Nerve I)
What are the names of the Foramen in the Middle Cranial Fossa?
- The Optic Foramen
- The Superior Orbital Fissure
- The Foramen Rotundum
- The Foramen Ovale
- The Foramen Spinosum
- The Foramen Lacerum
- The Carotid Canal
What structure(s) pass through the Optic Foramen?
The Optic Nerve (Cranial Nerve II)
What structure(s) pass through the Superior Orbital Fissure?
- The Occulomotor Nerve (Cranial Nerve III)
- The Trochlear Nerve (Cranial Nerve IV)
- The Ophthalmic Division of the Trigeminal Nerve (Cranial Nerve V1)
- The Abducens Nerve (Cranial Nerve VI)
- The Ophthalmic Artery
What structure(s) pass through the Foramen Rotundum?
The Maxillary Division of the Trigeminal Nerve (Cranial Nerve V2)
What structure(s) pass through the Foramen Ovale?
The Mandibular Division of the Trigeminal Nerve (Cranial Nerve V3)