Cranium, Meninges and the Brain Flashcards
What are the bones in the cranium?
frontal parietal (x2) occipital temporal (x2) sphenoid ethmoid
What are the facial bones?
maxilla (x2) zygoma (x2) nasal (x2) lacrimal (x2) vomer inferior conchae (x2) palatine (x2) mandible
What are sutures?
fibrous joints permitting little/no movement
Where are the coronal and sagital sutures?
coronal suture - between two parietal bones and frontal bone
sagital suture-runs along midline
What’t the different between an adult and newborn skull?
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
Where is the lambdoid suture?
between parietal and occipital bones
What landmarks replace the fontanelle in an adult skull?
anterior = bregma posterior = lambda
What provide the sensory innervation of the cheek?
one of the branches of the trigeminal nerve - infraorbital foramen in maxilla (cheek bone)
What nerve provides sensory innervation to the chin?
terminal sensory innervation of chin from another division of nerve
mental nerve goes through mental formane and provides sensory innervation of chin
What do the inferior conchae do?
breaks up air flow and moistens air as you breathe in
What are the parts of the ethmoid bone?
orbital plate
middle nasal concha
perpendicular plate
What is at the external acoustic meatus (on the temporal bone)?
the ear
What is the pterion?
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
Where is the occipitomastoid suture?
occipital bone sutures with mastoid process of temporal bone
Where is the palatine bone?
just behind the teeth
Where does the facial nerve (cranial nerve 7) emerge from at the base of the skull?
stylomastoid foramen
What are the cranial fossae?
anterior (posterior end defined by sphenoida crest), middle (posterior boundary defined by superior border of petrous part of temporal bone - temporal bone) and posterior
What are the bones just on top of the nose?
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
Where is the sella turcica?
in body of sphenoid
What is in the foramen magnum?
where the brainstem is continuous with spinal cord
What are the nerves in the base of the brain (anterior -posterior)?
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)
Where do the cranial nerves pass through the skull?
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
