WEEK 1 - SKULL AND MENINGES Flashcards
What are the two main functions of the skull
- supports the facial structures
- protective cavity for the brain
how many bones associated with the skull
29 bones
- 8 cranial bones
- 14 facial bones
- 1 hyoid bone
- 6 auditory bones (ossicles)
general features of the ARTICULATION between bones of the skull
- non-moveable sutures
- fibrous joints > ossify with age
what are the exceptions to the articulations
- temporomandibular joint and the ossicles of the ear
what forms first in the skull
- nerves, blood vessels, soft tissues
and then bones develop later
what is the processes/plates/spines
bony extensions from body for articulation with other cranial bones
what is the eminence
bony bump or elevation overlying a deep structure
what is the openings/foramina/canals
for blood vessels and nerves entering or leaving skull
clinical significance of emissary foramina
communication between pterygoid venous plexus on the outside of the cranial vault and the cavernous sinus on the inside of the cranial vault
what do large foramina and canals provide access for
major structures like carotid canal
what do smaller openings of skull are usually for
smaller branches of cranial nerves - petrotympanic fissure
what are the VERY small openings for tiny vessels are called
emissary foramina
skull lateral view - superior and inferior temporal lines attach to
- temporalis fascia and muscle
zygomatic bone features
- zygomaticoorbital foramen
- zygomaticofacial foramen
- zygomaticotemporal foramen
what does the zygomatic process of temporal bone articulate with
temporal process of zygomatic bone to form zygomatic arch
what is infratemporal fossa inferior to
temporal fossa
what is infratemporal fossa medial to
zygomatic arch
opens medially into pterygopalatine fossa
paranasal sinuses
paired
open into nasal cavities
what do paranasal sinuses do
lighten the weight of the head, support immune defense of nasal cavity, humidify inspired air, increase resonance of voice, crumple zone protection of vital structures
what type of texture is dura mater
dense and inelastic
list the two layers of dura mater
- periosteal layer (firmly adheres to the skull)
- meningeal layer (adheres to arachnoid mater)
what is a dural venous sinus a space between
two layers of venous blood
function of dural venous sinus in the skull
to drain blood from brain and cranial bone
there are no valves - ultimately drain into the venous system
what does the meningeal layer of the dura mater create
- several dural folds that divide the cranial cavity
function: to limit the rotational displacement of the brain
list the three meninges of the brain
- dura mater
- arachnoid
- pia mater
location of the dura mater
outer layer closest to and adheres to skull
arachnoid mater
middle layer of connective tissue projections (trabeculae) subarachnoid space contains CSF
Pia mater
thin inner layer closest to surface of brain and spinal cord, folds into sulci
list the dural folds of the brain
- falx cerebri
- falx cerebelli
- superior saggital sinus
- sella diaphragm
- tentorium cerebelli
list the notches of the anterior view of the head
- supraorbital notch
- infraorbital notch
- mental foramen
anterior cranial fossa features
- cribiform plate
- crista galli
middle cranial fossae features
- hypophyseal fossa
- dorsum sellae
- optic canal
- sof
- foramen rotundum
- foramen ovale
- foramen lacerum
posterior cranial fossa features
- clivus
- internal acoustic meatus
- jugular foramen
- hypophyseal canal
- foramen magnum
orbit openings posterior wall
optic canal
sof
iof
floor of orbit opening
infraorbital groove
infraorbital foramen
medial wall of orbit opening
- anterior and posterior ethmoidal foramina
- nasolacrimal canal
