Flashcards in Cardiovascular disease & its effect on vision Deck (92)
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1
what is a transient ischaemic attack known as
a temporary disruption go blood supply (that results on no long term damage)
2
what can a transient ischaemic attack be the result from
an embolism (such as a circulating fragment of an atheromatous plaque) temporarily blocking a vessel, the function of the area supplied by the vessels in impaired
3
what happens when the embolism moves on in a transient ischaemic attack
function returns
4
name an example of a specific TSA associated with the eyes
amaurosis fugax (fleeting darkness/blindness)
5
what is amaurosis fugax
a painless unilateral loss of vision resulting from a transient retinal ischaemia caused by an embolism in the retinal vasculature
6
what is the loss in vision described as by a patient, of amaurosis fugax
vision goes dark, like a curtain descending or ascending on the eye for a short period of time, which then vision goes back to normal
7
what do the inner 5 layers of the retina receive oxygenated blood from
central retinal artery
8
what is the central retinal artery a branch off
ophthalmic artery
9
what does the ophthalmic artery arise from
carotid artery (a branch off the aorta)
10
what happens in the ophthalmic artery as a result of amaurosis fugax
a dislodge is stuck in the ophthalmic artery, patient goes blind as the retina becomes ischaemic & stops functioning, then the blood clot breaks up and resolves itself whereby patient can see again
11
what may form a transient occlusion of a retinal vessel
an atheromatous plaque in the carotid artery which may disintegrate
12
what may emboli of an atheromatous plaque in the carotid artery which may form a transient occlusion of a retinal vessel be made of
various materials such as:
cholesterol crystals
platelet aggregates
lipid
13
instead of an emboli (which is most common), what else can be the cause of transient ischaemic event
vasopastic events such as:
unusual narrowing of vessels (artery contracts itself)
or
haematological causes such as:
abnormalities in blood constituents e.g. sickle cell anaemia
14
why is the CNS particularly susceptible to infarction
it needs a continuous supply of oxygen & CNS tissue does not regenerate
15
what are cerebrovascular accidents CVAs most commonly know as, and what causes it
stroke
blood supply to vessels which supply the brain become blocked so it becomes non functional (infarct)
16
what are the two sources which supply the brain with oxygenated (arterial) blood
- 2 internal carotid arteries
- 2 vertebral arteries
17
which part of the brain do the 2 internal carotid arteries supply
anterior
18
which areas do the 2 vertebral arteries supply
poster brain & spinal chord
19
what do the 2 vertebral arteries merge to form
basilar artery
20
what are the internal carotid & basilar arterial supplies united by
anterior & posterior communicating arteries at the circle of willis (found at the base of the brain)
21
why does the brain have two blood supplies
if one blood supply is impaired, the other can supply the brain
22
which three arteries arise fro the circle of willis
anterior cerebral artery
middle cerebral artery
posterior cerebral artery
23
what area of the brain does the anterior cerebral artery supply
front
24
what area of the brain does the middle cerebral artery supply
middle
25
what part of the brain does the posterior cerebral artery supply
back
26
what are the two types of stroke
- hemorrhagic
- occlusive (ischaemic)
27
what is a hemorrhagic stroke caused by
a ruptured aneurysm or an AVM
(blood comes/leaks out & that area of the brain does not receive oxygen from the vessel & that part of the brain stays dead forever)
28
what % does a hemorrhagic stroke account for from all strokes
20%
29
what is an occlusive (ischaemic) stroke caused by
a thrombosis (blood clot) on an atheromatous plaque
30
