- B3 1.5 Ventilating the lungs
- The lungs are in your thorax protected by your ribcage and separated from your abdomen by the diaphragm.
- The intercostal muscles contract to move your ribs up and out and flatten the diaphragm, increasing the volume of your thorax. The pressure decreases and air moves in.
- The intercostal muscles relax and the ribs move down and in, and the diaphragm domes up, decreasing the volume of your thorax. The pressure increases and air is forced out.