Cranium, Meninges and the Brain

Question 1

What are the bones in the cranium?

Answer 1

frontal
parietal (x2)
occipital
temporal (x2)
sphenoid
ethmoid

Question 2

What are the facial bones?

Answer 2

maxilla (x2)
zygoma (x2)
nasal (x2)
lacrimal (x2)
vomer
inferior conchae (x2)
palatine (x2)
mandible

Question 3

What are sutures?

Answer 3

fibrous joints permitting little/no movement

Question 4

Where are the coronal and sagital sutures?

Answer 4

coronal suture - between two parietal bones and frontal bone

sagital suture-runs along midline

Question 5

What’t the different between an adult and newborn skull?

Answer 5

sutures not completely formed

soft spot on newborns head (anterior fontanelle) - frontal and parietal bones have not yet fused
stays for at least 18 months - usually closed by 2 years

posterior fontanelle - parietal bones and occipital bones - usually closes by 2/3 months

Question 6

Where is the lambdoid suture?

Answer 6

between parietal and occipital bones

Question 7

What landmarks replace the fontanelle in an adult skull?

Answer 7

anterior = bregma
posterior = lambda

Question 8

What provide the sensory innervation of the cheek?

Answer 8

one of the branches of the trigeminal nerve - infraorbital foramen in maxilla (cheek bone)

Question 9

What nerve provides sensory innervation to the chin?

Answer 9

terminal sensory innervation of chin from another division of nerve
mental nerve goes through mental formane and provides sensory innervation of chin

Question 10

What do the inferior conchae do?

Answer 10

breaks up air flow and moistens air as you breathe in

Question 11

What are the parts of the ethmoid bone?

Answer 11

orbital plate
middle nasal concha
perpendicular plate

Question 12

What is at the external acoustic meatus (on the temporal bone)?

Answer 12

the ear

Question 13

What is the pterion?

Answer 13

junction at side of head between 4 bones of cranial vault (frontal,parietal, temporal and greater wing of sphenoid) - weak spot - blow to head here can cause fracture
just behind is the middle meningeal artery -> rupture-> extradural haemorrhage/haematoma

Question 14

Where is the occipitomastoid suture?

Answer 14

occipital bone sutures with mastoid process of temporal bone

Question 15

Where is the palatine bone?

Answer 15

just behind the teeth

Question 16

Where does the facial nerve (cranial nerve 7) emerge from at the base of the skull?

Answer 16

stylomastoid foramen

Question 17

What are the cranial fossae?

Answer 17

anterior (posterior end defined by sphenoida crest), middle (posterior boundary defined by superior border of petrous part of temporal bone - temporal bone) and posterior

Question 18

What are the bones just on top of the nose?

Answer 18

crista galli and cribiform plate around - olfactory neurones penetrate through base of skull to synapse with olfactory bulb- sits on inferior surface of frontal lobes

Question 19

Where is the sella turcica?

Answer 19

in body of sphenoid

Question 20

What is in the foramen magnum?

Answer 20

where the brainstem is continuous with spinal cord

Question 21

What are the nerves in the base of the brain (anterior -posterior)?

Answer 21

olfactory bulbs -> optic chiasm and two optic nerve -> (infundibulum/papillary stalk) -> mamillary body -> occulomotor nerve -> trochlear nerve -> trigeminal nerve (5) -> juntion between pons and medulla - medial = C nerve 6 (adjucent), lateral = 7 (facial) and most lateral = 8 (vestibulocochelear nerve)
-> c nerves 9,10 and 11 in a row (glossopharyngeal nerve, vagus and accesory)

Question 22

Where do the cranial nerves pass through the skull?

Answer 22

Olfactory - cribriform plate
Optic - optic canal
Occulomotor - superior orbital fissure
Trochlear - superior orbital fissure
Trigeminal - 1 superior orbital fissure
                        2 foramen rotundum
                        3 foramen ovale
Abducent - superior orbital fissure
Facial - internal acoustic meatus 
Vestibular cochlear - internal acoustic meatus 
Glossopharyngeal - jugular foramen 
Vagus - jugular foramen
Accessory - jugular foramen (/foramen magnum)
Hypoglossal - hypoglossal canal