Take a deep breath! We’ll guide you to the amazing world of breathing…
1. Muscles of the diaphragm contract when breathing in.
2. When this happens, the diaphragm flattens from its previous shape of an upwards dome.
3. Intercostal muscles between the ribs contract when breathing in.
4. This moves the rib cage up and out.
5. The combined effect of the above is to increase the volume of the thorasic cavity (chest)
6. The increased volume of the chest decreses air pressure within the lungs, forcing air in from outside.
7. When breathing out, diaphragm and intercostal muscles relax reversing the effects of contraction.
8. The air pressure in the lungs increases, forcing out air.
9. Inhaled air is approximately 78% nitrogen, 21% oxygen, about 0.04% carbon dioxide and 1% other gases (eg argon).
10. Exhaled air is approximately 78% nitrogen, 16% oxygen, 4% carbon dioxide plus the other gases and an indeterminate amount of water vapour (which is a waste product of respiration).
11. The air sacs (alveoli) of the lungs have a massive surface area.
12. This massive surface area makes diffusion of gases to and from the lungs more efficient (oxygen from lungs to blood, carbon dioxide from blood to lungs).
13. The oxygen is bound by the iron containing compound haemoglobin in red blood cells and carried to other parts of the body to be used in respiration.
14. The walls of the alveoli are very thin making diffusion of gases more efficient.
15. Carbon dioxide (waste product of respiration) diffuses out of the blood plasma to the lungs at the aveoli.
16. The airways (trachea, bronchi and bronchioles) are lined with cells with hair-like projections called cilia.
17. The airways also have mucus producing goblet cells.
18. The mucus from the goblet cells traps dirt, bacteria and viruses.
19. The cilia waft and move the muck-containing mucus up and out.
20. This exits the breathing system as snot or phlegm.
Stop by often to find out more interesting breathing facts with Breathslim!