Base of the skull, orbit, eye & ear Flashcards
What are the 3 cranial fossa?
Anterior
middle
posterior
What does the anterior cranial fossa contain?
The frontal lobe
What does the orbital part of the frontal bone form?
The roof of the orbit and the forehead
Where is the middle cranial fossa located and what does it hold?
below and behind the anterior cranial fossa and contains the temporal, parietal and occipital lobe
Where is the posterior cranial fossa located and what does it hold?
Lowest part and hold the midbrain and cerebellum
What structure forms the roof of the nasal cavity?
The ethmoid bone
What are the names of the 2 other structures that make up the ethmoid bone?
The cribriform plates
Crista galli
What does the cribriform plate support?
Supports the olfactory bulb
What does the ethmoid bone transmit?
Olfactory nerves
Clinical
What can the cribriform plate spread ?
Tumors in the upper part of the nasal cavity to the anterior cranial fossa
Which BONE acts as a site for the attachment for the flax cerebri?
The frontal bone
What structure on the ethmoid also acts as a site of attachment for the flax cerebri?
Crista galli
What is the name of the process that arises at the end of the anterior cranial fossa
The lesser wing
What does the lesser wing act as an attachment for?
The tentorium cerebelli
Where is the pituitary fossa located?
In the middle cranial fossa
What is another name for the pituitary fossa
Sella turcica
What is the function of the sella turcica?
Holds and supports the pituitary gland
Where is the superior orbital fissure located?
Underneath & lateral the lesser wing, lateral to the sella turcica
What cranial nerves run through the superior orbital fissure?
CN III- oculomotor
CN IV- trochlear
CN V1 trigeminal- ophthalmic branch
CN VI- abducens
Where is the optic canal located?
Medial to the lesser wing
What CN runs through the optic canal?
CN II optic nerve
What CN nerve runs through the foramen rotundum?
CN V2- trigeminal- maxillary branch
What CN runs through the foramen ovale?
CN V3- trigeminal- mandibular branch
What CN runs through the foramen spinosum?
CN V3 meningeal branch and artery and veins
What are the 4 foramina that are immediately lateral to the central part of the middle crainal fossa?
Superior orbital fissure
foramen rotundum
foramen ovale
foramen spinosum
What foramina in the posterior cranical fossa is part of the temporal bone?
Internal acoustic meatus
What CN runs through the internal acoustic meatus
CN VII- facial
CN VIII- vestibuloccochlear
What is the name of the large opening that lies centrally in the floor of the posterior cranial fossa?
Foramen magnum
What does the foramen magnum transmit?
Medulla, spinal accessories and arteries