Mechanics Of Breathing

Question 1

When we INHALE:

1) chest cavity
2) diaphragm
3) intercostal muscles
4) which in turn reduces air pressure…

Answer 1

1) changes shape and size
2) flattens and moves downwards
3) contract and raise up and push out the sternum. This makes the chest cavity larger

4) and causes air to be sucked into the lungs.
REMEMBER: gases move from an area of high concentration to an area of low concentration to reach equilibrium

Question 2

WHEN WE EXHALE:

1) diaphragm
2) intercostal muscles

Answer 2

1) becomes dome shaped and it moves upwards
2) relaxes, lowering the ribs and dropping the sternum, there fore making the chest cavity smaller. This increases air pressure inside of the air cavity

Question 3

Why do the lungs expand and contract more during exercise?

Answer 3

Because more air is inhaled to supply more oxygen to the working muscles

And more air is exhaled to remove carbon dioxide produced by the working muscles

Question 4

During exercise more muscles assist with breathing.

Explain how additional muscles support with both inhalation and exhalation

Answer 4

The pectorals and sternocleidomastoid assist in raising the sternum when you inspire.

The abdominal pull the rib cage down more quickly, forcing air out quickly when you expire.