3.1 Skull osteology Flashcards
frontal bone starts as a pair then fuses. try or false?
true
metric suture
failure of frontal pair of bones to fuse
which portion of the temporal bone is within the calvaria?
squamous
the anterior and posterior fontanelles form which structures?
bregma and lambda
treatment of severe craniosynostosis
break the ossified joint so normal growth can occur
name of arteries that run through dipole of skull
diploic
what coats the inner lining of skull bone?
periosteum (aka periosteal layer of dura mater)
which bones form the anterior cranial floor?
-frontal
-ethmoid
-greater wing of sphenoid bone
importance of crista Galli
attaches to falx cerebri
importance of cribriform foramina
passage of olfactory nerves to roof of nasal cavity
importance of perpendicular plate
forms nasal septa
the ethmoid bone is pneumatised. what does this mean?
air filled cavities called paranasal air sinuses
relation of sella turcica and pituitary gland
pituitary gland sits in pituitary fossa of sella turcica
lesser wings of sphenoid bone form what?
posterior part of anterior cranial fossa
role of petrous part of temporal bone
houses middle and inner ear structures
-anterior semicircular canal
-cochlea
-vestibulocochlear nerve
-posterior semicircular canal
-ear canal
superior nuchal line of occipital bone function
attachment for trapezius muscle
at what point does the brainstem continue as spinal cord?
foramen magnum
types of skull fracture
-linear
-comminuted
-depressed
-non depressed
which part of skull base is fractured to give signs…
-periorbital ecchymoses
-CSF ottorhea
-CSF rhinorrhea
-battles sign
-blood behind eardrum
-anterior cranial fossa- orbital plate fracture
-petrous bone in middle cranial fossa
CSF rhinorrhea
clear fluid dripping from nose with head injury= CSF
imaging choice for facial injuries/fractures. why?
plain xray- not as much concern for brain, neuromuscular structures underneath
sign of supraorbital ridge fractures
slice through eyebrow
are maxilla fractures rare and uncomplicated?
rare
but could fall backwards to occlude airway
best view for suspected
-zygoma fracture
-maxilla fracture
-bucket handle view
-OPG (pan across, usually 2 fractures)
what is the TMJ?
articulation between mandibular fossa of temporal bone and condyle of mandible
what type of joint is TMJ?
synovial hinge type
-lined with fibrocartilage
-fibrocartilaginous disc
nerve supply to TMJ
auriculotemporal nerve (sensory, branch of mandibular division of trigeminal)
pain location in TMJ pathology?
can radiate to side of head, jaw
importance of coronoid process
temporalis muscle insertion
what stabilises the TMJ?
joint capsule + 3 extracapsular ligaments
2 movements of TMJ, and what produces the movement?
rotation: inferior joint capsule
gliding: superior joint capsule (retraction, protraction)
dislocation of TMJ
condyle of mandible passes anteriorly in front of articular tubercle, jaw locks open and muscles of mastication keep joint locked
reduction technique for TMJ dislocation
strength, push down of jaw to relax muscles of mastication then slide back into mandibular fossa
label 1.6 of GW page 42
-
what do the following transmit?
-superior orbital fissure
-optic canal
-foramen rotundum
-foramen ovale
-foramen lacerum
-foramen spinous
-carotid canal
-nerves
-optic nerve
-maxillary trigeminal nerve
-mandibular trigeminal nerve
-filled with cartilage, ICA over top
-middle meningeal artery
-ICA
peaked ridge of petrous part of temporal bone forms what?
boundary between middle and posterior cranial fossa
nerve carrying sense of hearing and balance arises from where? exits through where?
arises from petrous part of temporal bone
exits via internal auditory meatus to brainstem
facial nerve exits skull where?
stylomastoid foramen
which blood vessel begins on exiting jugular foramen of skull?
IJV
why do frontal and maxilla bones look black on X-ray?
paranasal sinuses- contain air
name 3 extra cranial fossa
- temporal
- infra temporal
- pterygopalatine
