Fact: Your brain can survive without your heart… for a while.
If your heart stops, you’re a goner unless someone can get it started again pretty much immediately. Right? Well, actually, you might be OK for quite some time.
When your heart stops pumping, your blood stops moving and the brain becomes starved of both oxygen and glucose, both of which are essential to keep it alive. Brain cells are quite fragile and, on top of that, whist most cells can use fats and proteins as fuel in an emergency, but brain cells are entirely dependent on glucose from the blood. Thus, the brain is the most sensitive organ to a lack of blood supply and so is the first thing to go after a cardiac arrest.
Hence during a heart attack your brain is suffocating, leading to brain damage and eventually death. However, new research shows that without a blood supply from the heart, the brain can soldier on for a whole eight minutes before it suffers any permanent damage.
We still don’t understand quite how the brain achieves this seemingly impossible resilience, but its great news for us. But don’t get complacent: your brain might be able to survive up to 8 minutes on its own, but CPR can buy you up to half an hour. Time to get yourself on a first aid course – it could save someone’s life.
‘Another one of Mr Shaunak’s Little Bites of Science’
Image under Creative Commons license, taken by Ton Haex