Respiratory Movements

Question 1

Respiratory Tree

Answer 1

Trachea
Primary bronchi
Smaller bronchi
Bronchioles
Alveoli

Question 2

Kinetic theory of gasses

Answer 2

Pressure is generated by collisions of molecules

The more frequent and harder the collisions the higher the pressure

Question 3

Boyles law

Answer 3

Pressure is inversely proportional to volume at a constant temperature

Question 4

Water vapour pressure

Answer 4

Inspired aid is saturated with water vapour in the upper airways

Saturation “dilutes” the gasses

At 37°, partial pressure of saturated water vapour pressure = 47 mmHg

Question 5

Dalton’s law of partial pressure

Answer 5

Pressure exerted by each gas in a mixture of gasses is independent of the other gasses present

Total pressure of a mixture of gasses is equal to the sum of the individual gas pressures

Question 6

Inspiration

Answer 6

Rib cage - expands
Lungs - stretched
Diaphragm - move downward
Alveolar pressure - reduced
Air is drawn into the lungs

Question 7

Expiration

Answer 7

Rib cage - contracts
Lungs - contract
Diaphragm - move upwards
Alveolar pressure of- increased
Air is pushed out of lungs

Question 8

Pulmonary ventilation rate

Answer 8

Frequency x Tidal Volume

At rest - 12 breaths/min x 0.5 l/breath = 6l/min

Question 9

Alveolar ventilation rate

Answer 9

Not all air passing the lips reaches the alveoli for gas exchange

AVR - the actual amount of air that reaches the alveoli

To calculate AVR, allow for the “wasted” ventilation of dead spaces

Question 10

Perfusion

Answer 10

Deoxygenated blood passes through the lungs and becomes re-oxygenated