Workshop5: Respiratory air flow and volume

Question 1

Explain what happens during inspiration

Answer 1

Diaphragm goes down and Cavity pressures decrease

This allows air to move in causing lungs to expand

Question 2

Explain what happens during expiration

Answer 2

Diagrapm moves back to resting position and Cavity pressure increases
This causes air to move out and is aided by elastic lung recoil

Question 3

What are the components of the PowerLab pneumotachometer

Answer 3

Plastic tubes, Flow head, Clean bore tubing, Filter, Mouthpiece

Question 4

What does the powerlab pneumotachometer do?

Answer 4

Measures air flow and changes in lung volume

The pneumotachometer has a pressure difference on either side of the membrane with known resistance

The pressure difference is proportional to flow rate

Note: Expiratory volume is always larger than inspiratory volume

Question 5

What is RR?

Answer 5

Respiratory rate (in breaths/min)

Question 6

What is VE?

Answer 6

Expired minute volume

Ve = RR x Vt (in L/min)

Question 7

What are the lung volumes?

Answer 7

Tidal volume, Vt,
Inspiratory Reserve Volume, IRV
Expiratory reserve volume, ERV
Residual volume, RV

(in L)

Question 8

What are the lung capacities?

Answer 8

Inspiratory capacity, IC
Exiratory capacity, EC
Vital capacity, VC
Functional residual capacity, FRC
Total lung Capacity, TLC

(in L)

Question 9

What is Inspiratory capacity?

Answer 9

IC = VT + IRV

Question 10

What is expiratory capacity?

Answer 10

EC = VT + ERC

Question 11

What is Vital capacity?

Answer 11

VC = IRV + ERV + VT

Question 12

What is Functional residual capacity?

Answer 12

FRC= ERV + RV

Question 13

What is total lung capacity?

Answer 13

TLC = VC + RV

Question 14

What are the pulmonary function tests?

Answer 14

PIF in L/min
PEF in L/min
FVC in L
FEV1 in L
FEV1/FVCx100 (%)