•When we breathe in our rib cage swing upwards and outwards, diaphragm contracts and flattens, the expand and air is drawn in. The thorax also increases.
•When we breathe out our rib cage swing inwards and downwards, diaphragm relaxes and arches up, lungs become smaller and air is drawn out. The thorax size also decreases.
• During inhaling the concentration of oxygen is more
• During exhaling the concentration of carbon dioxide is more.