Lecture 2 The Skull and Cranial Cavity Flashcards
what is the scalp
tissues covering the skull superficially
what makes up the scalp
Skin Connective tissue (dense) aponeurosis of occipitofrontalis muscle Loose connective tissue periosteum of the skull
Which layer of the scalp will contain the majority of the blood vessels supplying the tissues of the scalp?
dense connective tissue
what happens when the scalp is lacerated
bleed profusely
why does the scalp bleed profusely
dct unable to retract to original position so bv’s stay open
Aponeurotic layer and loose connective tissue moves
what must happen when suturing the scalp
all layers closed in suturing
what is the skull
bony casing surrounding the brain
what makes up the skull
neurocranium
viscerocranium
what is the neurocranium
bones surrounding the brain
what is the viscerocranium
facial skeleton
how do the skull bones join
at sutures
form at 5y/o
what is the skull like before the sutures close
cartilaginous structures called fontanelles present
allow brain to move and grow
what makes up the neurocranium
most bones share names with lobe of brain they cover parietal occipital temporal sphenoid frontal ethmoid
what makes up the viscerocranium
nasal lacrimal vomer maxilla zygoma inferior conchae mandible
what makes up the viscerocranium
nasal lacrimal vomer maxilla zygoma inferior conchae mandible
which bone does not directly suture to the frontal bone
mandible
what is the pterion
suture point between the frontal, parietal, temporal and sphenoid
weak point
what runs deep to the pterion
middle meningeal artery (MMA)
what may occur in children before the pterion closes
hydrocephalus
due to cartilage so can move to increase space and reduce pressure
In adult intercranial pressure will affect brain, deficits and death as pressure cannot be relieved
what is an aneurysm and haemorrhage
Aneurysm is weakness in blood vessel wall
Haemorrhage is the rupture of aneurysm
Pressure causes brain to shift due to compromised vasculature
what is a foramina
small hole
sites of exit (eg veins and cranial nerves) and entry (arteries)
what is cranial nerve I
olfactory
what is cranial nerve II
Optic
what is cranial nerve III
oculomotor (move eye)
what is cranial nerve IV
Trochlear (muscle)
what is cranial nerve V
trigeminal (portions of the face)
V1 ophthalmic
V2 Maxillary
V3 Mandibular
what is cranial nerve VI
Abducens (abduct eye)
what is cranial nerve VII
facial
what is cranial nerve VIII
Vestibulocochlear (inner ear)
what is cranial nerve IX
Glossopharyngeal (tongue)
what is cranial nerve X
Vagus (everything)
what is cranial nerve XI
accessory (shrug shoulders)
what is cranial nerve XII
hypoglossal (tongue)
what runs through the cribriform plate
Foramina
CN1
What runs through the optic canal
foramina
CN2, ophthalmic artery
what runs through the superior orbital fissure
CN3,4,6,5(V1)
What runs through the rotundum
CN5 V2
What runs through the ovale
CN5 V3, AMMA
What runs through the spinosum
MMA
What runs through the lacerum
carotid artery runs over the top
what runs through the internal acoustic meatus
CN7 and 8
what runs through the jugular foramen
CN9,10,11,IJV
What runs through the hypoglossal canal
CN12
What runs through the hypoglossal canal
CN12
What runs through the magnum
spinal cord
what are the cranial foramen
cribriform plate, optic canal, superior orbital fissure, rotundum, ovale, spinosum, lacerum, internal acoustic meatus, jugular foramen, hypoglossal canal, magnum
what are therein arteries that supply the brain
internal courted artery and vertebral artery (L and R)
what do the main arteries supplying the brain do
the branches anastomose to form the cerebral arterial circle
aka circle of willis
what do the vertebral arteries do
enter at foramen magnum where they unite to form the basilar artery
Where is the common carotid found
deep to sternocleidomastoid
useful pulsation point
internal supplies brain
external carotid supplies face
what forms the cerebral arterial circle
anastomosis between 2 internal carotid arteries and 2 vertebral arteries
allow for collateral circulation
what does the cerebral arterial circle give rise to
anterior
middle
posterior
-cerebral arteries
what does the anterior cerebral artery do
supplies medial and superior surfaces of the brain and frontal pole
what does the middle cerebral artery do
supplies the lateral surfaces and temporal pole
what does the posterior cerebral artery do
supplies the inferior surfaces and occipital pole
what causes strokes
embolism in cerebral artery as no anastomoses of cerebral arteries once in brain so no way to avoid ischaemia leading to neuro deficit
what is a mnemonic to remember the cranial nerves
Oh Oh Oh to touch and feel a girls vagina, so hot
