Respiratory movements

Question 1

What is the purpose of alveoli?

Answer 1

Permit gas transfer and allow O2 pass from the lungs to the blood

Question 2

What are the 2 parts of the respiratory tree?

Answer 2

Conducting system

Exchange surface

Question 3

What is the makeup of the conducting system? (4)

Answer 3

Trachea
Primary bronchi
Small bronchi
Bronchioles

Question 4

What is the makeup of the exchange surface and what is special about it compared to the conducting system?

Answer 4

Bronchioles
Alveoli
- special: large SA, compact and compressed

Question 5

What are the 4 gas laws respiration is dependent on?

Answer 5

Volume of lungs
Pressure of lungs and atmosphere
Temperature - physiological
Movement of O2 and CO2

Question 6

What is the kinetic theory of gases? (2)

Answer 6

Correlation between pressure and movement of molecules.

The more frequent and harder the collisions, the higher the pressure

Question 7

What is Boyle’s law? (2)

Answer 7

P = 1/V

Pressure is inversely proportional to volume at a constant temperature

Question 8

What is the significance of water vapour in the respiratory system? (4)

Answer 8

All respiratory surfaces are moist
O2 comes into contact with the moisture
O2 is diluted from 21kPa to 19.9kPa O2
Lung O2 is 13.3kPa - general dilution

Question 9

What is Dalton’s law of partial pressure? (2)

Answer 9

Pressure exerted by each gas in a mixture of gases is INDEPENDENT of the other gases present

Total pressure of a mixture of gases is EQUAL TO THE SUM of the individual gas pressures

Question 10

What are the main changes of pressure at sea level and altitude?

Answer 10

Barometric pressure: 101kPa -> 33.7kPa

Partial pressure: 19.9kPa -> 5.8kPa

Question 11

What is the diffusion pathway of O2 in the alveoli? (5)

Answer 11

Air: 21.2kPa
Respiratory: 19.9kPa (moved down)
Alveoli: 13.3kPa (move down)
Venous blood in: 5.8kPa (move down)
Venous blood out: 13.3kPa

Question 12

What is the diffusion pathway of CO2 out of the blood? (4)

Answer 12

Venous blood in: 6.0kPa
Venous blood out: 5.3kPa
Alveoli: 5.3kPa
Air: 0kPa

Question 13

What happens when we inspire? (5)

Answer 13

Rib cage: expands
Lungs: stretch
Diaphragm: move downward
Alveolar pressure: reduced
Air drawn into the lungs

Question 14

What happens when we expire? (5)

Answer 14

Rib cage: contracts
Lungs: contract
Diaphragm: moves upwards
Alveolar pressure: increased
Air is pushed out of the lungs

Question 15

What is pulmonary ventilation rate?

Answer 15

Frequency x tidal volume

12 x 0.5

Question 16

What is alveolar ventilation rate (Va)?

Answer 16

The actual amount of air that reaches the alveoli

Question 17

What is perfusion?

Answer 17

Deoxygenated blood passing through the lungs and becoming re-oxygenated

Question 18

What is the ventilation - perfusion ratio?

Answer 18

Va / Q

Question 19

What happens when perfusion is impaired?

Answer 19

Dead space occurs

Question 20

What is dead space? (3)

Answer 20

Normal ventilation, no perfusion
No capacity to take O2 away or bring CO2 to alveoli
No gas exchange between alveoli and blood

Question 21

What happens when the alveolar ventilation rate is impaired?

Answer 21

A shunt occurs

Question 22

What happens when a shunt occurs? (2)

Answer 22

No ventilation, normal perfusion

No new O2 into the system, alveoli equilibrates with venous blood

Question 23

What happens where there is low O2? (2)

Answer 23

Constriction of pulmonary arterioles

Hypoxia

Question 24

What happens when there is high O2? (2)

Answer 24

Dilates pulmonary arterioles

Foetus

Question 25

What happens when there is low CO2? (2)

Answer 25

Bronchioles constrict

Hypocapnia

Question 26

What happens when there is high CO2? (2)

Answer 26

Bronchioles dilate

Lung disease