Lung Volumes & Capacities

Question 1

What is tidal volume?

Answer 1

amt of air inspired and expired in a single normal breath

normal = 500mL

Question 2

What is residual volume?

Answer 2

air that cannot be forced out

Question 3

What is inspiratory reserve volume?

Answer 3

additional volume that can be inhaled above the tidal volume

Question 4

What is expiratory reserve volume?

Answer 4

additional volume that can be exhaled below tidal volume

Question 5

What is total lung capacity?

Answer 5

maximal volume to which lungs can be expanded with greatest effort

Question 6

What is functional residual capacity?

Answer 6

amt of air that remains in the lungs following a normal expiration

Question 7

What is vital capacity?

Answer 7

amt of air that can be maximally inspired following a maximal expiration

Question 8

What is inspiratory capacity?

Answer 8

air that can be maximally inspired following a normal exhale

Question 9

What volumes are contained within TLC?

Answer 9

IRV
TV
ERV
RV

Question 10

What volumes are contained within FRC?

Answer 10

ERV and RV

Question 11

What volumes are contained within VC?

Answer 11

IRV, TV and ERV

Question 12

What volumes are contained within IC?

Answer 12

TV and IRV

Question 13

Clinical: Helium Dilution

Answer 13

• inhalation of a known [He] from a known V

- change in concentration allows determination of FRC

Question 14

Clinical: Body Plethysmography

Answer 14

• pt sits in enclosed rigid box
• breathes against a shutter

-P in the lungs changes and the P in the box changes proportionally, but opposite (P1V1=P2V2)

Question 15

Clinical: Nitrogen Washout Technique

Answer 15

• pt breathes 100% oxygen through a 1-way valve
• expired gas is collected and monitored until nitrogen reaches zero
• volume is multiplied by % of nitrogen in mixed expired air