Cerebrovascular Disease Flashcards
1
Q
Why does extracellular potassium increase/sodium decrease in ischaemic brain tissue?
A
- Lack of blood supply
- Lack of Oxygen
- Lack of ATP
- Na/K ATPase channe; dysfunction
- Sodium remains in the cells
- Potassium cannot enter the cell
2
Q
Why does intracellular calcium increase in ischaemic brain tissue?
A
- Ca in the cell is normally in low concentrations
- It’s stored in the sarcoplasmic reticulum
- Low Calcium concentration in the cell relies on ATP
- Due to lack of ATP
- Calcium escapes into the cell’s cytoplasm
3
Q
Why does intracellular pH decrease in ischaemic tissue?
A
- Lack of Oxygen
- Lack of ATP
- Anaerobic metabolism/glycolysis
- Lactic acid build up
4
Q
Why does the membrane potential rise in ischaemic brain tissue?
A
- Potassium maintains RMP
- BUT, Potassium cannot enter cell
- As Na/K ATPase channel is dysfunctional
5
Q
Why is high extracellular glutamate in ischaemic brain tissue bad?
A
- Glutamate is the brains excitatory neurotransmitter
- It produces action potentials
- High amounts of Glutamate cause high amounts of action potentials
6
Q
Why is high intracellular calcium in ischaemic brain tissue bad?
A
- can form reactive oxidative species
- Lipid per oxidation
- Calpains
- Cell death
7
Q
3 signs of stroke (FAST)
A
- Facial Weakness
- Arm weakness
- Speech problems
- Time (call 999)
8
Q
What are the stroke care guidelines?
A
- Excluding haemorrhage
- You give aspirin/clopidogrel/heparin after 14 days due to risk of haemorrhage
- Tissue plasminogen activator
9
Q
before you give tPA
A
- requires neuroimaging to exclude haemorrhage
- you are estimating outcome
- opens up artery
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