Lung Volumes and Capacities

Question 1

what is the definition of vital capacity (VC) ?

Answer 1

the volume of air that can be forcefully exhaled after maximal inhalation

Question 2

what is the equation for vital capacity (VC) ?

Answer 2

inspiratory reserve volume + tidal volume + expiratory reserve volume
IRV + TV + ERV

Question 3

what is the definition of tidal volume (TV) ?

Answer 3

the volume of air inhaled and exhaled in a normal quiet breath

Question 4

what is a normal tidal volume (TV) ?

Answer 4

500mL

Question 5

what is a normal vital capacity (VC) ?

Answer 5

2400mL

Question 6

in restrictive lung diseases what is the FEV1/FVC ratio and why?

Answer 6

normal or increased
FEV1 decreases
FVC also decreases, but more drastically due to limited lung expansion

Question 7

what can happen due to pulmonary fibrosis?

Answer 7

fibrosis = scarring = thicker alveolar walls = long diffusion time (slower gas transfer across alveoli)

Question 8

what is the definition of FEV1?

Answer 8

the volume of air forcefully exhaled in the 1st second after maximal inhalation

Question 9

how can airway resistance be calculated?

Answer 9

Poiseuille’s Law
it is inversely proportionate to the radius^4

Question 10

what bronchioles have the least resistance?

Answer 10

terminal bronchioles

Question 11

what bronchioles have the greatest resistance?

Answer 11

intermediate bronchioles

Question 12

what is the definition of inspiratory reserve volume (IRV) ?

Answer 12

the volume of additional air inhaled above the tidal volume

Question 13

what is a normal inspiratory reserve volume?

Answer 13

3000mL

Question 14

what is the definition of total lung capacity?

Answer 14

the total volume of air in the lungs after maximal inhalation

Question 15

what is the equation for total lung capacity?

Answer 15

vital capacity+ residual volume
VC + RV

Question 16

what is the definition of expiratory reserve volume (ERV) ?

Answer 16

additional volume of air exhaled above the tidal volume during maximal expiration

Question 17

what is a normal expiratory reserve volume (ERV) ?

Answer 17

1000mL

Question 18

what is the definitional of functional residual capacity (FRC) ?

Answer 18

the amount of air left in the lungs after quiet exhalation of tidal volume

Question 19

what is the equation for functional residual capacity (FRC) ?

Answer 19

expiratory reserve volume + residual volume
ERV + RV

Question 20

what is the definition of lung compliance in relation to volume and pressure?

Answer 20

the change in volume that the lungs achieve per unit change in pressure

Question 21

what is the definition of residual volume (RV) ?

Answer 21

the volume of air remaining in the lungs after maximal exhalation

Question 22

what is a normal residual volume (RV) ?

Answer 22

1200mL

Question 23

what is the definition of anatomical dead space?

Answer 23

areas of the body where there is no gas exchange but there is ventilation
i.e trachea
constant value

Question 24

what is a normal functional residual capacity (FRC) ?

Answer 24

2400mL

Question 25

what is alveolar dead space?

Answer 25

space in the alveoli that are ventilated but not perfused

Question 26

what is the definition of minute ventilation?

Answer 26

the product of tidal volume and respiratory rate

Question 27

what is the calculation for minute ventilation?

Answer 27

tidal volume (mL) + breaths/min unit = mL/min

Question 28

what is a normal total lung capacity?

Answer 28

6000mL

Question 29

what is surfactant made of?

Answer 29

phospholipids

Question 30

what is the definition of inspiratory capacity?

Answer 30

the volume of air inhaled during maximal inhalation after normal exhalation?

Question 31

what is a normal inspiratory capacity?

Answer 31

3500mL

Question 32

what is a normal vital capacity?

Answer 32

male - 4500mL female - 3500mL