Mechanics of breathing/spiromter APPLIED ANATOMY AND PHYSIOLOGY

Question 1

What happens during inhalation?

Answer 1

The intercostal muscles contract and move the ribs upwards and outwards. The diaphragm contracts and flattens. This increases the space in the thorax/chest cavity, creating an area of low pressure. This allows air to move in because it travels from high pressure to low pressure.

Question 2

What happens during exhalation (expiration)?

Answer 2

The breathing muscles relax. the diaphragm curves and returns to normal shape. The weight of the ribs causes them to descend and the chest volume decreases. This reduction in size of the chest cavity increases the pressure of the air in the lungs and causes it to be expelled.

Question 3

Define lung volume.

Answer 3

The amount of air breathed in, out and found within the lungs at any time.

Question 4

Define tidal volume.

Answer 4

The normal amount of air inhaled or exhaled per breath (increases during exercise).

Question 5

Define expiratory reserve volume.

Answer 5

The amount of air that can be forced out after tidal volume (decreases after exercise).

Question 6

Define inspiratory reserve volume.

Answer 6

The amount of air that can be forced in after tidal volume (decreases during exercise).

Question 7

Define residual volume.

Answer 7

The amount of air that remains in the lungs after maximal expiration (no change during exercise).

Question 8

Define vital capacity.

Answer 8

The largest volume of air that can be forcibly expired after the deepest possible inspiration.