• What is it? When something scary happens, like running into a bully, our bodies react. This is called the "fight or flight" response (coined by Walter Cannon in 1932).

• How it Feels: Ever felt your heart pound, pupils get big, or your body shake? That's your body preparing to deal with a threat by giving you the energy to fight or run away!

Real-world Example: Imagine you stumble upon a wild, snarling dog on your way home. Your body activates the "fight or flight" response, preparing you to either confront the dog or run away fast!

• Central Nervous System (CNS): Made of the brain and spinal cord. It's like the boss of your body.
• Peripheral Nervous System (PNS): This has two parts:
• Somatic System: Deals with skin and muscles, like telling your hand to swat a fly.
• Autonomic System: Handles stress and consists of two parts:
• Sympathetic: Kicks in during emergencies. Imagine you need to lift a heavy object off a friend; this gives you a boost.
• Parasympathetic: Calms things down, like after you've won a game and need to relax.

Sympathetic vs. Parasympathetic: These two can't work at the same time. One revs you up; the other cools you down.

Real-world Example: Think of a car. The sympathetic system is the gas pedal, and the parasympathetic system is the brake. Both are needed, but not at the same time!