Roles of the ribs, intercostal muscle and diaphrag
Ribs : Prevent the collapsing of lung cavities due to the pressure changes
They are attached to the intercostal muscles to move up or down and out or in
Intercostal muscle: contracts to pull the ribcage outwards and upwards to increase the volume of the lung cause pressure to fall, leading to the entry of air due to pressure gradient.
Relaxs to fall downward and inwards to decrease the volume of the lung causing increase in pressure leading to the rushing of air out of the lungs.
Diaphragm: Contract to move downwards increasing the volume of the lungs and decreasing the pressure
Relax to decrease the volume of the lungs and increase the pressure