The Breathing System
When we breathe, air moves into and out of our body. There are two movements involved in the process of breathing:
- Inspiration (also known as inhalation) – This is breathing air into the body.
When we inspire:
Expiration (also known as exhalation) – This is breathing air out of our body.
- The intercostals muscles found between the ribs contract.
- This raises the ribs upwards and outward expanding the ribcage
- diaphragm contracts and flattens, pulling downwards.
- The result is that the thorax increases in volume, which in turn lowers the pressure inside it and consequently air is sucked into the lungs.
When we expire:
- The intercostal muscles relax.
- This lowers the ribs downwards and inwards.
- The diaphragm relaxes, moving back upwards.
- The result is that the thorax decreases in volume, which in turn increases the pressure inside it and consequently forces air out of the lungs.