Chapter 3: Vasculature of CNS Flashcards
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The principal source of nourishment for the CNS is?
glucose
to maintain a constant brain volume, CSF is ?
returned to the blood through structures that function like valves between the subarachnoid space and dural sinuses
Ischemia:______
reduction of arterial blood supply to an area of the CNS, = decrease delivery of oxygenated blood to tissue terming ISCHEMIA
simple terms:
- some part of ur body is not getting enough blood, so its not getting enough oxygen
decreased blood supply (ischemia) usually happens when?
- artery becomes occluded (blocked/ closed) by (embolus or stenosis)
- drop in systemic blood pressure (ex, during Heart attack)
blood supply of spinal cord
- ant spinal A
- post spinal A
blood supply of Medulla
- ant spinal A
- post spinal A
- vertebral A
- PICA
blood supply of pons
- basilar A
- AICA
- Superior cerebellar A (SCA)
blood supply of Cerebellum
- PICA
- AICA
- Superior cerebellar A (SCA)
blood supply of Midbrain
- Basilar A
- Superior cerebellar A (SCA)
- Post Cerebral A
blood supply of frontal lobe
- middle cerebral
- ant cerebral
blood supply of parietal lobe
- middle cerebral A
- ant cerebral A
blood supply of occipital lobe
- post cerebral A
- Middle Cerebral A
blood supply of temporal lobe
- post cerebral A
- Middle Cerebral A
TIA (Transient Ischemic Attack) is a ________
brief reduction in blood flow which will produce transient neurological signs
if iscgemia is presistant and is uncorrected for several minutes it can cause _________
death of the tissue, termed an infarction, this can result in more enduring or even permanent (ischemic stroke)
Collateral circulation is
alternate or “backup” blood vessels in your body that can take over when another artery or vein becomes blocked or damaged.
under special circumstances because of this a ischemic stroke or infarction may not occur
HEMORRHAGIC STROKE can occur when
an artery ruptures, releasing blood into surrounding tissue
HEMORRHAGIC STROKE example
aneurysm or ballooning of artery
which STROKE produces a loss of downstream flow but also can damage brain tissue at the rupture site
HEMORRHAGIC STROKE
principal blood supply for the brain
ant circulation:
post circulation:
ant circulation: internal carotid arteries
post circulation: vertebral arteries
middle cerebral artery passes through what?
sylvian fissure or lateral sulcus
true or false? brain stem receives blood only from the posterior circulation
true
true or false? cerebral hemispheres receive blood from both ant, and post circulations
true
true or false? most cerebral veins drain first into the dura sinuses
what is the arterial supply of the spinal cord?
- spinal A post and ant
- radicular A’s
the cervical spinal cord is supplied by?
- vertebral A
- radicular A’s
true or false when spinal cord segments are supplied by a single artery they are less likely to be vulnerable to infarction?
false
more likely to be vulnerable to infarction?
the thoracic, lumbar, and sacral segments of the spinal cord are supplied manly by?
- radicular A’s
true or false? segments that receive redundant or collateral blood supply tend to fare better following single vessel occlusion
true
Artery Of Adamkiewicz supplies what?
lower portion of spinal cord (t8)
interuption of blood supply to critical areas can?
produce sensory and motor control impairments
what is the blood supply of the brain stem?
- Vertbral A
- Bassilar A
spinal arteries come _______ whereas arteries supplying the brainstem supply _______
ventrally and dorsally whereas arteries supplying the brainstem supply dorsally
true or false the spinal arteries supply a small portion of the medulla?
true
true or false occlusions of the medulla blood supply can cause impairments in voluntary limb movement and sensation
true because, the arteries that supply the medulla also supply axons of the Corticospinal tract and the medial Lemniscus
what is the name of the junction that allow the to vertebral arteries to join and form the basillar Artery
PONTOMEDULLARY JUNCTION
DORSAL MEANS
BACK/ UPPER SIDE, (POST)
ROSTRUAL MEANS
TOWARDS NOSE
CAUDAL MEANS
TOWARDS TAIL
VENTRAL MEANS
TOWARD STOMACH
What supplies the caudal portion of the cerebellum
PICA
What supplies the rostral portions of the cerebellum
AICA
SCA- Superior Cerebellar A
the basilar A splits where to make cerebral arteries
pons medulla border
__________ A nourishes most of the midbrain
Post Cerebral A
the colliculi is the principal portion of the
Tectum (roof)
what are the four segments of the internal carotid Artery
and which to segments form the carotid siphon?
- Cervical Segment: enters carotid canal
- Intrapetrosal Segment: courses through petrous portion of temporal bone
- Intracavernous segment: courses through cavernous sinus + venous structure overlying sphenoid bone
- Cerebral segment: extends to bifurcation of internal carotid art (ant and mid cerebral art)
intracavernous + cerebral portions form the carotid siphon
the posterior communicating A primarily supplies?
diencephalon structures
the anterior chorodial art supplies?
diencephalon
subcortical telencepahlic structures
post limb of internal capsule
true or false? everyone has a complete circle of willis
false. more than 50% of people have incomplete circle of Willis’s
and because this people may not compensate for an occluded artery.
The internal capsule plays a crucial role in
________________
It’s made up of different parts:
Anterior limb: Carries fibers ______
Posterior limb: Contains important ___________
Genu: The bend between the anterior and posterior limbs, containing _____________
transmitting motor and sensory information between the cortex and the spinal cord, as well as between different parts of the brain.
connecting the frontal lobe to the thalamus.
motor fibers that travel from the motor cortex to the brainstem and spinal cord, as well as sensory fibres.
fibers important for motor control of the face and head.
the basal ganglia is supplied by?
- ant & middle cerebral A
- ant chorodial A
thalamus is supplied by?
post cerebral A
post communicating A
internal capsule is supplied by?
ant, middle, post cerebral A
ant chorodial A
the hypothalamus is supplied by?
ant cerebral
post cerebral
ant communicating
post communicating
the cerebral cortex is supplied by the ?
distal branches of the:
- ant Cerebral A
- middle Cerebral A
- post Cerebral A
the middle cerebral begins at _____ of internal carotid and courses through the _______
bifurcation
lateral sulcus
the anterior cerebral art courses through _________
saggital fissue
cerebral veins drain into
dural sinuses
superficial veins arise from ______ underlying ______.
cerebral cortex
white matter
what is an example of a deep cerebral vein
internal cerebral vein
the dural sinus functions as _________
low pressure channels for venous blood flow back into systemic circulation
the sinuses are located between
the dura layers the Periosteal and meningeal layer
the superficial cerebral veins drain into the
superior and inferior sagittal sinus
csf circulation:
choroid plexus
lat ventricles
interventricular formamina
csf enters 3rd ventricles
cerebral aquaduct
fourth ventricle
subarachnoid space via apatures
