After loss of blood supply to the brain, how long will it take to cause unconsciousness?
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0 - 2 Secs
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2 - 4 Secs
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4 - 6 Secs
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8 - 10 Secs
D
Correct answer
Explanation
When blood supply to the brain is completely interrupted (as in cardiac arrest), unconsciousness typically occurs within 8-10 seconds due to the rapid depletion of oxygen in cerebral tissues. The brain has minimal oxygen reserves and cannot sustain consciousness without continuous blood flow. Earlier timeframes (2-6 seconds) are too brief for complete oxygen depletion.