1. Your frontal cortex-the "executive" part of your brain behind your forehead-receives the information about the threat you're facing.
2. The frontal cortex sends a blaring message of emergency to the hypothalamus, the brain's hormones control center.
3.The hypothalamus sets up a chain reaction, triggering the stress hormones adrenaline and cortisol.
4. The heart starts pumping 18 to 20 quarts of blood a minute, a whopping 400 percent increase over its normal 4 to 5 quarts.
5. Your blood pressure rises, your breathing quickens, your eyes dilate, your muscles tighten, your airways winden and you become hyper-alert.
6. The blood moves away from the gut (digestion's not important at this moment), the skin (you don't want to bleed too much from the bear bite) and kidneys (so you don't lose fluids), and heads toward the muscles, where the arteries dilate, giving you greater access to energizing nutrients.
7. The inflammatory part of your immune system revs up, ready to attack any bacteria or other foreign body that invades.
8. Your fat cells release more fat info the blood for quick access to energy.
9. Your blood platelets turn sticky, the better to clot should that bear slash you.
10. Your liver converts glycogen, the raw stuff of fuel, into glucose for energy.
11. You're primed to fight or flee.
2. The frontal cortex sends a blaring message of emergency to the hypothalamus, the brain's hormones control center.
3.The hypothalamus sets up a chain reaction, triggering the stress hormones adrenaline and cortisol.
4. The heart starts pumping 18 to 20 quarts of blood a minute, a whopping 400 percent increase over its normal 4 to 5 quarts.
5. Your blood pressure rises, your breathing quickens, your eyes dilate, your muscles tighten, your airways winden and you become hyper-alert.
6. The blood moves away from the gut (digestion's not important at this moment), the skin (you don't want to bleed too much from the bear bite) and kidneys (so you don't lose fluids), and heads toward the muscles, where the arteries dilate, giving you greater access to energizing nutrients.
7. The inflammatory part of your immune system revs up, ready to attack any bacteria or other foreign body that invades.
8. Your fat cells release more fat info the blood for quick access to energy.
9. Your blood platelets turn sticky, the better to clot should that bear slash you.
10. Your liver converts glycogen, the raw stuff of fuel, into glucose for energy.
11. You're primed to fight or flee.
