1. Is it likely that the basilar artery would have a blockage?
If a blockage was to occur in the posterior cerebral arteries, what damage might occur?
Damage to the visual processing functions, and damage to the brain stem, which in turn means damage to cranial nerves (10 of 12 nuclei located in brain stem)
where do the carotid and vertebral systems meet?
Circle of Willis
What connect the major systems, and what are they known as?
Communicating arteries, known as anastomoses.
What do the anastomoses make possible?
Collateral Circulation. This allows blood to flow through an alternate route, in hopes that in the event of an occlusion, the deprived area would still receive blood.
Blood from the ______ and ______ system generally do not mix, but if a _______ occurs, blood will flow between these systems via the __________
4. anastomoses (communication arteries)
Areas between major cerebral arteries (vascular supplies) are boundary zones known as _________
Watershed regions are particularly susceptible to _______ and ________ resulting in disorders like ____________.
3. transcortical sensory aphasia
1. The blood-brain barrier serves as a:
2. it is __________ allowing...
3. Endothelial cells have ____ but they are tightly packed, making it very the barrier difficult to pass through
4. _______ or ________ can disrupt the blood-brain barrier
1. Protective mechanism
2. semi-permeable, oxygen to pass but not other substances
4. A tumor, meningitis
Cerebral veins empty used blood into the ___________ which takes blood back to the ________ via the ____________.
1. Dural Sinuses (all three connected)
3. Jugular vein
Occlusions/vascular problems in the veins/dural sinuses are:
rare, there are many functional anastomoses in this area
Interruption in the blood supply:
Stroke or CVA
Blood does not flow to a portion of the brain (caused by an occlusion of the artery)
1. bleeding into the brain tissue, results when a weakened artery ruptures.
2. hardening/narrowing of the artery
death of a portion of brain tissue
Necrotic region of tissue
Tissue plasminogen activator (TPA):
1. Only FDA approved drug for ischemic strokes
2. clot breaking drug
3. has a time limit (within 3 hours)
4. 3% of stroke victims receive this
1. blood clot formed within a vessel
2. part of blood clot that travels in the bloodstream
Four general locations for hemorrhage:
Balloon like swelling of arterial walls, tend to happen at points of bifurcation. Can be caused by metabolic disorders, congenital defects, trauma, tumors, high blood pressure
Arteriovenous Malformation (AVM)
congenital disorder in which large connections exist between arteries and veins (tangle of arteries), they tend to grow over time and can result in neurological problems.