1b. Head HAL - Worksheet Flashcards
the brain and spinal cord are surrounded by what
meninges
what doe the meninges do
what is their function
2 function
3 layers help anchor and protect the brain and spinal nerves
house important vessels and CSF to supply brain with nutrients and remove waste
what are the 3 meninges layers inner and outermost
dura - outer
arachnoid
pia - inner
what is the dura mater - what is its appearance
thick and dense membrane
what are the 2 parts that make up the dura mater
outer periosteal layer and inner meningeal layer
what lies between the outer periosteal layer and inner meningeal layer of the dura mater
dural venous sinuses
4 of them
what is between the periosteal layer and bone of the dura mater
extradural space
what is the arachnoid maters appearance
very thin layer deep to dura
how is the arachnoid mater connected to the pia mater
suspended by attached to pia mater by delicate connective tissue trabeculae
what is the space between the pia and arachnoid mater
subarachnoid space
what does the subarachnoid space hold
CSF and cerebral blood vessels supplying the brain tissue
what is a feature of the arachnoid mater
arachnoid granulations
where do the arachnoid granulations protrude
into the dural venous sinus
what is the appearance of the pia mater and what is it attached to
thin, almost imperceptible layer
adherent to and inseparable from the brain and spinal cord tissue
what are the major causes of extradural hemorrhage/hematoma within the skull
meningeal artery rupture from trauma
what are the major causes of subdural hemorrhage/hematoma within the skull
communicating vein rupture from trauma
what are the major causes of arachnoid hemorrhage/hematoma within the skull
cerebral artery rupture (aneurysm)
where do extradural hemorrhage/hematoma occur within the skull
between periosteal dura and bone
where do subdural hemorrhage/hematoma occur within the skull
within meningeal dura layer
where do sub arachnoid hemorrhage/hematoma occur within the skull
between arachnoid and pia
what types of vessels are involved in extradural, subdural and sub arachnoid hemorrhage/hematoma
extradural & subarachnoid = artery
subdural = vein
which of the extradural, subdural and sub arachnoid hemorrhage/hematoma is the worst and why
least = subdural mid = extradural worst = sub arachnoid
arteries worse than veins, deeper worse than superficial
where do the CSF originate from
in the walls of ventricles
where is CSF located
in subarachnoid space surrounding the outside of the brain and spinal cord
what are the 4 ventricles in the brain
2 lateral, 3rd and 4th ventricles
what is the shape of the lateral ventricles
bilateral C shaped spaces
where is the lateral ventricles located in relation to the structures around it
inferior to corpus callosum
loop over, behind and under the thalamus on each side
what does the 3rd ventricle look like and where is it located
irregularly shaped space that connects 2 lateral ventricles
positioned in midline between the 2 thalami
what does the 4th ventricle look like
diamond shaped cavity
where is the 4th ventricle located
in midline between the pons and cerebellum
what connects the 3rd and 4th ventricles
by cerebral aqueduct
how can you use the ventricles to identify brain pathologies such as haemorrhage or space occupying lesions
asymmetry/loss of expected fluid filled space due to compression of haemorrhage
as fluid is squeezed out by pressure of injury
the arteries supplying the brain originate from where and ascend in how many pathways
originate from aortic arch vessels
2 pathways
what are the 2 pathways that the arteries supplying the brain ascend the neck
from the common carotid artery on each side
from the subclavian artery on each side
where does the internal carotid artery enter the base of skull and where does it reemerge from
via carotid canal and reemerges through the foramen lacerum
what vessel that supplies the brain is given off the common carotid
internal carotid artery
what vessel that supplies the brain is given off the subclavian artery
vertebral artery
the vertebral artery ascends in where
ascends in the transverse foramina of the cervical vertebrae
the vertebral artery unites with its counterpart to form what vessel
basilar artery
the basilar artery enter the skull through what
foramen magnum
which 2 vessels unit to form the anatomic ring at the base of the brain
what is the ring of vessels also known as
internal carotids and basilar artery
aka: circle of willis
what 3 major cerebral arteries supplying the brain arises from the circle of willis
anterior, middle and posterior cerebral artery
which lobe does the anterior cerebral arteries head toward
frontal lobe
which lobe does the middle cerebral arteries head toward
temporal lobe
which lobe does the posterior cerebral arteries head toward
occipital lobe
which meningeal space are the cerebral arteries located in and what effect might a ruptured cerebral artery aneurysm have
subarachnoid space
rupture will cause subarachnoid haemorrhage/haematomo
describe the path of artery vessels from the aortic arch to the brain on the left side
what is the difference from the right side of the arteries path
aortic arch -> Left subclavia and Left common carotid artery
subclavian -> vertebral artery -> basilar artery -> circle of willis
common carotid artery -> internal and external carotid arteries -> circle of willis
right side has a braciocephalic trunk from the aortic arch that divides into the subclavian and the common carotid artery
the middle meningeal artery enters the skull from which feature
foramen magnum
what injury type would put the middle meningeal artery at risk and what consequence would it have
trauma to skull eg blow to head
consequence = extradural haemorrhage
the smaller veins in the skull collect into what structures
large dural venous sinuses
what layers does the dural venous sinuses lie between
periosteal layer and meningeal layer of the dura mater
the dural venous sinuses are/arent interconnected and end at what feature
are interconnected
end at the jugular foramen
the internal jugular vein of the neck is formed where
at the jugular foramen
what are the 5 main dural venous sinuses
which are paired and which arent
unpaired:
superior sagittal sinus
inferior sagittal sinus
paired:
cavernous sinus
transverse sinus
sigmoid sinus
where can the superior sagittal sinus be found
midline roof of the skull
where can the inferior sagittal sinus be found
base of falx cerebri
where can the transverse sinus be found
horizontal path along occipitals
where can the sigmoid sinus be found
s shaped and ending in the jugular foramen
what sort of injury might occur by tearing one of the small cerebral veins connecting through to a sinus
subdural haemorrhage
where is the cavernous sinus located
either side of the sella turcica
the cavernous sinus has key relations to what 5 structures
optic chiasm pituitary gland sphenoid sinus internal carotid arteries cranial nerves
what is clinically significant about the fact that the cavernous sinus is connected to the veins of the face
infections in the face can track back into and spread in the brain
what might you see on an axial cross section image of someone with an inflammed sinus on one side
asymmetry - lack of air space as inflammed tissue and fluid fills cavity space
what key feature of the middle cranial fossa does the sphenoid sinus sit inferior to
sella turcica/pituitary
the sphenoid sinus can be used surgically to access what part of the brain that is located in the sella turcica
pituitary gland
what are the folds and grooves called in the brain
what do they do for the brain
grooves = sulci folds = gyri
increase surface area to increase neural capacity
what issues are there wil differentiating the lobes of the brain from each other
brain tissues are a continuum so not many definable landmarks
what cranial fossa is the temporal lobe in
middle
what cranial fossa is the cerebellum located in
posterior
where does the brain stem exit the cranium
through foramen magnum
what 2 structures sits inferior to the cerebrum
cerebellum and brain stem
what are the 3 parts of the brain stem from top to bottom
mid brain, pons and medulla oblongata
what plane can we see the thalamus and hypothalamus
mid sagittal
the thalamus is what kind of structural appearance and is located where in relation to the lateral ventricles
bilateral ovoid structures
thalamus located infero-lateral to the CSF filled lateral ventricles
what does the thalamus do
relay signals between the body and rest of brain
what is the basal ganglia’s position relative to the thalamus
antero-lateral to thalamus
what does the hypothalamus do
hormone regulation
what is at the base of the hypothalamus
pituitary gland
what is the optic chiasm appearance
2 optic nerves emerge from the optic canals at the top of the X shape
what effects might you see in a patient with a suspected pituitary gland tumor
visual defects/disturbance
could be both or one side
what does the pineal gland do
controls circadian rhythm
where is the pineal gland located
midline posteriorly between the 2 thalami
what can happen to the pineal gland and what does this look like on the xray images
can become calcified and looks like a white spot in xrays
what is the corpus callosum
arching bridge of myelinated white matter tracts connects left and right hemispheres of the brain, allowing the 2 hemispheres to communicate and coordinate
