Skull & Cranial cavity Flashcards
SCALP
i) what does SCALP stand for?
ii) what does it extend over?
ii) what are the two branches of innervation to the scalp?
i) Skin
Connective tissue
Apneurotic layer
Loose connective tissue
Pericranium
ii) extends over the neurocranium
ii) innervation by the trigeminal nerve and spinal cutaneous nerves
BONES OF THE SKULL
i) what are the two main parts of the skull? which part holds the brain?
ii) how many bones are in each part?
iii) what bones are shown in blue, lime green, yellow, orange, dark green, purple and white?
i) neurocranium (holds the skull) and the viscerocranium
ii) Neurocranium = 8 bones (occipital, 2x temporal and parietal, sphenoid, ethmoid, frontal)
viscerocranium = 2x nasal conchae, nasal bones maxilla, palatine, zygomatic, lacrimal and a vomer and mandible
iii) blue = frontal bone
lime green = temporal
yellow = sphenoid
orange = zygomatic
dark green = maxilla
white = mandible
purple = lacrimal
SKULL FORAMINA
what structures pass through
i) cribiform plate
ii) optic canal
iii) sup orbital fissure
iv) rotundum
v) ovale
vi) spinosum
vii) lacerum
viii) int acoustic meatus
ix) jugular foramen
x) hypoglossal canal
xi) magnum?
i) CN1 - olfactory nerve
ii) CN2 - optic nerve
iii) CN3,4,V1,6 - oculomotor, trochlear, opthalmic division of trigeminal and abducens
iv) V2 - maxillary division of trigeminal
v) V3 - mandibular division of trigeminal
vi) middle meningeal artery
vii) traversed by the carotid artery
viii) CN7,8 - facial and vestibulocochlear nerve
ix) CN 9,10,11 - glossopharyngeal, vagus and accessory
x) CN 12 - hypoglossal nerve
xi) spinal cord
Name the foramina A-J
A = cribiform plate B = optic canal C = sup orbital fissure D = foramen rotundum E = foramen ovale F = spinosum G = carotid canal H = int acoustic meatus I = jugular foramen J = hypoglassal canal
MENINGES
i) what are the three layers?
ii) give four functions of the meninges
i) dura, arachnoid and pia
ii) protection, support for blood vessels, cushion and nourish the brain, stop crushing of nerves exiting the brain, helps with changes in gravity
DURA MATER
i) how many layers is the dura made of? what are they called and where are they found?
ii) which layer stops when it gets to the spinal cord?
iii) which nerves supply the dura? (4)
iv) which nerve is the anatomical basis for headaches?
v) what is the blood supply? what foramina does this pass through?
vi) where may the two layers not be stuck to eachother?
i) two layers
1) endosteal layer - stuck to periosteum of the skull
2) meningeal layer - wraps brain and spinal cord
ii) endosteal layer stops at the spinal cord
iii) nerve supply - trigeminal, vagus, C1-3 and sympathetic
iv) C1-3
v) blood supply by middle meningeal artery which passes foramen spinosum
vi) two layers will not be stuck to eachother in a dural sinus
MENINGEAL LAYER OF THE DURA
i) what is one of its main roles? what does this allow in relation to movement of the brain?
ii) name the folds that seperate
a) cerebral hemis
b) the cerebellar from the cerebral hemis
c) the two cerebellar hemis?
iii) what is the point of attachment for (a)?
iv) what are labels A & B?
i) role in creating folds/septa which divide the cranial cavity and prevent movement of the brain
ii) a) falx cerebri
b) tentorium cerebelli
c) falx cerebelli
iii) falx cerebri attaches at the crista galli
iv) A = falx cerebri
B = tentorium cerebelli
DURA - CLINICAL APPLICATION
i) what pathology is associated with dural stretching?
ii) what type of haematoma does damage to the middle meningeal artery cause?
iii) what type of herniation may a space occupying lesion that causes hernation of the temporal lobe be called?
iv) what is seen in the pic?
i) dural stretching = headache (assoc C1-C3)
ii) middle meningeal damage = epidural/extradural haematoma
iii) hernation of temporal lobe = tentorial herniation
iv) an extradural haematoma
ARACHNOID MATER
i) does this layer have a blood supply?
ii) what cell type allows this layer to have projections?
iii) all structures passing to/from the brain pass through the subarachnoid space - true or false?
iv) what is the name of the space that contains CSF? what produces CSF and how much is made per day?
v) what structures allow transfer of CSF to the venous sinuses? where does the CSF then head to be filtered?
vi) what are labels A-C in the diagram?
i) no - it is avascular
ii) fibroblasts
iii) true
iv) sub arachnoid space contains CSF which is produced by the choroid plexus - 500ml per day
v) arachnoid granulations allow transfer of CSF to sinus then it heads to the kidney to be filtered
vi) A = arachnoid granulation
B = arachnoid mater
c = sub arachnoid space
PIA MATER
i) does it have a blood supply?
ii) how does it interact with the gyri and sulci
iii) what creates the periarterial space?
i) yes its vascular
ii) intertwines with the gyri and sulci
iii) the cerebral arteries enter the brain carrying a sheath of pia mater with them = periarterial space
CLINICAL APPLICATION OF MENINGES
i) what is leptomeningitis? which layers does it affect?
ii) what area may the infection enter and what would this cause?
iii) what appearance would be seen in this infection?
i) infection and inflammation of the arachnoid and pia mater (aka leptomeninges)
ii) can enter the sub arachnoid space and enter the blood which would cause septicaemia
iii) creamy white exudate on the surface of the brain may be seen
DURAL SINUSES
i) where do these sinuses sit and what do they recieve?
ii) what type of endothelium do they have? do they have valves or smooth muscle?
iii) what do they drain into?
iv) name labels A-F?
i) sit between the dural folds (between meningeal and endosteal layer) and recieve drained blood and CSF from the brain via cerebral veins
ii) have thick walled endothelium with no valves or smooth muscle
iii) drain into the internal jugular vein
iv) A - inferior saggital sinus
B - superior saggital sinus
C - straight sinus
D - sigmoid sinus
E - transverse sinus
F - cavernous sinus
BLOOD SUPPLY TO THE BRAIN
i) what are the two main arteries that supply the brain?
ii) what do the branches anastomose to form?
iii) what are the two terminal branches inside the skull?
iv) which arteries pass within the cervical vertebrae and enter the foramen magum and unite to form the basilar artery?
v) the vertebral artery is a branch of which major vessel?
vi) where does the internal carotid artery travel through/transverse?
i) internal carotid and vertebral artery
ii) branches join to form the cerebral arterial circle (circle of wilis)
iii) two terminal branches are anterior cerebral and middle cerebral
iv) vertebral arteries pass in vert then through foramen magnum then unite to the basilar
v) vert artery is a branch of the subclavian
vi) int carotid travels through the carotid canal and transverses the foramen lacerum
what are labels A - C?
A = common carotid
B = vertebra artery
C = internal carotid
CEREBRAL ARTERIAL CIRCLE (OF WILIS)
i) what arteries is it formed by the anastomoses of?
ii) what is the function of the circle? when does this function not work so well?
iii) name labels A-H
i) formed by 2xinternal carotid arteries and 2xvertebral arteries
ii) function is to provide collateral circulation in case of blockage but not good in sudden occulsions (better for blockage over time)
iii) A - anterior cerebral artery
B - middle cerebral artery
C - posterior cerebral artery
D - basilar artery
E - vertebral artery
F - internal carotid
G - anterior communicating
H - posterior communicating
CEREBRAL ARTERIES
which surfaces and poles of the brain do the
i) anterior cerebral artery
ii) middle cerebral artery
iii) posterior cerebral artery
supply?
iv) which arteries are shown in blue, red and green?
i) medial and superior surface and frontal pole
ii) lateral surface and temporal pole
iii) inferior surface and occipital pole
iv) blue = anterior cerebral
red = middle cerebral
green = posterior cerebral
