• Breathing = getting oxygen-rich air from the environment into our lungs.
• Mostly involuntary (happens automatically) but can be controlled (like holding our breath underwater 🐠 or puffing up a balloon 🎈).

Real-world example: Imagine how you breathe normally without thinking but can control it when you're swimming or trying to blow candles on a birthday cake!

• Air flows from high to low pressure (it's just physics!).

• For inhaling: Pressure in our lungs < Pressure in the atmosphere 🌬️.

  • How? The diaphragm (a muscle at the base of our chest) contracts.
  • Result? Lungs expand, reducing pressure inside them, and we inhale.

Real-world example: Think of a vacuum cleaner. It sucks in dust because of the difference in air pressure!

• Exhaling at rest is passive (like a free ride 🎢, no energy needed).
• Diaphragm relaxes = lungs reduce in volume = we exhale.

• During exercise: Muscles = hungry for oxygen & producing more carbon dioxide 🚴‍♂️💨.
• Result? Faster inhaling and exhaling.
• Some extra chest and abdomen muscles join the breathing party to help.

Real-world example: When you're jogging or doing any workout, you'll notice your breathing getting faster. That's because your muscles are asking for more oxygen!