Cerebrovascular System Flashcards
Your brain LOVES ____
*Your brain LOVES blood
Especially oxygenated blood
Uses about 20% of your total blood supply
- About half of the things that can go wrong inside of your skull are related to the cerebrovascular system
- 10-15 seconds without oxygenated blood to brain –> pass out
- 3-5 minutes without oxygenated blood to brain –> irreparable damage
Therefore, it is actually important and we need to talk about it
Internal carotid (function) **
– anterior blood circulation
Blood going to the front part of brain
Vertebral arteries (right and left)
- posterior blood circulation
anterior communicating artery
- Left and right anterior cerebral arteries joined by the anterior communicating artery
- Approximately 1/3 of aneurysms occur here. Leads to vision loss due to proximity to the optic chiasm
Middle Cerebral Artery Supplies…
- Most of the temporal lobe
- Primary motor cortex for upper extremities
- Primary somatosensory cortex for lower extremities
- Assorted lateral surfaces of the brain
- Insula
basilar artery (how formed)
- The vertebral arteries pass through the foramen magnum and join to form the basilar artery.
- Frequently referred to as the vertebrobasilar system
Posterior Cerebral Arteries Supply
- Posterior cerebral cortex
- A lot of your diencephalon
- Midbrain
(I think important for visual system)
Vasocorona
- meshwork of vessels
Embolism
*A blockage or occlusion in an artery- embolus
*Includes thrombus (thrombosis)
*Leads to ischemia (reduced blood flow)
*Area supplied by the artery with the embolus loses oxygenated blood supply
Can lead to infarction (tissue death)
*Common cause of stroke (ischemic stroke)
ischemic stroke
An embolism is a common cause of an ischemic stroke
infarction
means tissue death
Aneurysms
- Dilation of blood vessel
- Blood cannot pass well through this point
- Walls of artery weaken
- Leads to ballooning of vessel and possible rupture of vessel
*Cause of hemorrhagic stroke
Arteriovenous Malformations
- Something did not develop correctly
- Generally comes in the form of a weird tangle of blood vessels
- This can lead to areas not getting enough blood flow or to a weakening/rupture of the tangled branches
- Why do they happen? Great question. No real answer. *There does not appear to be a strong genetic component either. However, we do know that there is a lot of variability in the formation of the vascular system between people. (Example: source of the anterior spinal artery)
Internal Carotid Splits into …
Once it enters the skull, the internal carotid artery splits into:
- Anterior cerebral arteries (right and left)
- Middle cerebral artery (right and left)
Note- these are the terminal branches, not the only branches of the internal carotid
Anterior cerebral arteries bring blood to what part of the brain?
(the frontal mostly)
The septal area Primary motor cortex for lower extremities Motor planning areas in the frontal lobe Primary somatosensory cortex lower extremities Most of the corpus callosum Optic chiasm Hypothalamus Parts of the caudate and putamen
T/F the Anterior Cerebral Artery has branching
TRUE
Middle Cerebral Artery (characteristics)
Usually larger than the anterior cerebral artery
Has multiple smaller branches
There is no communicating artery between the right and left middle cerebral arteries
Interestingly, it can be created surgically to help treat aneurysms and occlusions of the middle cerebral artery
Blood gets to your brain initially through the *****
internal carotid and vertebral arteries
there is some overlap= probs a good thing
vertebrobasilar system
The vertebral arteries pass through the foramen magnum and join to form the basilar artery.
Which part of the vertebral artery is particularly susceptible to injury?
(and um why?)
The V4 segment of the vertebral artery is particularly susceptible to injury
The basilar artery splits into the ___?
-when/where?
- The basilar artery splits into the right and left posterior cerebral arteries
- I think at the level of the pons
*The basilar artery also gives rise to the superior cerebellar artery
The basilar artery also gives rise to the anterior inferior cerebellar artery
superior cerebellar artery
-travels near:
The basilar artery also gives rise to the superior cerebellar artery
The superior cerebellar artery travels near the oculomotor and trochlear nerves
Supplies the upper (superior) cerebellum and part of the midbrain
anterior inferior cerebellar artery
The basilar artery also gives rise to the anterior inferior cerebellar artery
*The anterior inferior cerebellar artery supplies the anterior inferior portions of the cerebellum
vertebral arteries gives rise to
- join to form the basilar artery
- Posterior inferior cerebellar artery
- Anterior spinal artery
- Posterior spinal artery (sometimes)
Posterior inferior cerebellar artery
- posterior inferior part of the cerebellum
What artery does the vertebral artery give rise to that gives the blood supply for your medulla and parts of the cerebellum
Posterior inferior cerebellar artery- posterior inferior part of the cerebellum
Anterior spinal artery-
-runs:
supplies anterior portion of spinal cord
runs down the median of the spinal cord on the anterior side (motor side)
Cerebellar Arteries
The superior cerebellar artery, anterior inferior cerebellar artery, and the posterior inferior cerebellar artery anastomose (are connected)
Posterior spinal artery
- supplies posterior portion of the spinal cord
25% of time it comes from the vertebral arteries, 75% of the time it comes from the posterior inferior cerebellar artery
Posterior spinal arteries (2)- run down the left and right sides of the spinal cord on the posterior side
(sensory side)
Spinal Arteries
- Anterior spinal artery
- Posterior spinal arteries (2)
- Vasocorona- meshwork of vessels
- Medullary segmental arteries
Vasocorona
- meshwork of vessels
Spinal Arteries
Medullary segmental arteries
- supply additional blood flow to areas with the most need (near cervical and lumbar enlargements)
What artery supplies the Basal ganglia?
the Middle cerebral artery
What artery supplies the thalamus?
The posterior cerebral artery
What artery supplies a lot of the outside portion of the brain?
Middle cerebral supplies a lot of outside portion
In a medial brain… what artery supplies a lot?
the anterior cerebral artery (slide 29)
Venous Flow **
Venous outflow from the brain travels through superficial and deep veins
The superficial and deep veins drain into the dural venous sinuses.
(-ultimately all funneling towards the same place=> Internal Jugular vein)
Internal jugular vein
The final exit point for blood in your skull is through the internal jugular vein
Blood from the dural venous sinuses drains into it
Things That Can Go Wrong with cerebrovascular system (3)
- Embolism
- Aneurysms
- Arteriovenous Malformations
What is the cause of hemorrhagic stroke
Aneurysms
Vertebral arteries join –>
basilar artery
neural crest cells arise from the _____ aspect of the neural tube
-yes I am throwing it back to this lecuture
dorsal aspect
where do approximately 1/3 of aneurysms occur
anterior communicating artery
(A) can be created surgically to help treat aneurysms and occlusions of the (A)
middle cerebral artery
do the internal carotid and vertebral arteries have overlap
yes
does the Middle Cerebral Artery have a communicating artery
NO
