1.16 The Mechanics Of Breathing

Question 1

What are the mechanics of inhalation?

Answer 1

1. The diaphragm and intercostal muscles contact
2. Diaphragm flattens and pulls bottom of lungs down
3. Intercostal muscles pull ribs, and therefore lungs outwards
4. Lungs increase in size and air pressure inside the lungs is reduced
5. Air pressure outside the body is now higher than inside the body. Air travels from areas of high pressures to areas of low pressure, and so air is pulled into lungs

Question 2

What happens to lungs during inhalation during exercise?

Answer 2

Extra muscle make chest cavity even bigger, to pull even more air in. This is because the working muscles need more oxygen during exercise

Question 3

What are the mechanics of exhalation?

Answer 3

1. The diaphragm and intercostal muscles relax
2. The diaphragm moves back up into a dome shape
3. The relaxed intercostal muscles allow ribs and lungs to move inwards
4. The lungs reduce in size and the air pressure inside the lungs is increased
5. The air pressure outside the body is now lower than air pressure inside the body. Air travels from areas of high pressure to areas of low pressure so air leaves the lungs

Question 4

What happens to lungs during exhalation during exercise?

Answer 4

Extra muscles are used to force air out, which allows you to breath more frequently and more deeply. This is because carbon dioxide is created and needs to be exhaled