Ventilation And Airflow

Question 1

4 steps of external respiration

Answer 1

1.Ventilation (inhalation of oxygen containing air and exhalation of CO2 rich breath)
2.Alveolar gas exchange
3.Gas transport in the blood between lungs and tissues
4.Exchange of O2 and CO2 between blood and tissues

Question 2

What is boyles law

Answer 2

Boyle’s law states that the pressure within a system is inversely proportional to the volume

Question 3

During inspiration the volume of the lungs increases so pressure…

Answer 3

Decreases, so air moves down its pressure gradient into the lungs from the atmosphere

Question 4

During inspiration the external intercostal muscles
And the diaphragm are…

Answer 4

Contracted

Question 5

What is tidal volume

Answer 5

Volume of air which enters with each breath (avg. 0.5L)

Question 6

What is the inspiratory reserve volume

Answer 6

Extra volume that can be inspired above tidal volume – maximum inspiration (avg. 2.5L)

Question 7

What is the expiratory reserve volume

Answer 7

Extra volume that can be expired above tidal volume – maximum expiration (avg. 1.5L)

Question 8

What is the residual volume

Answer 8

Air remaining in lungs after maximum exhalation – this residual air prevents lungs from collapsing (avg. 1.5L)

Question 9

What is the inspiratory capacity

Answer 9

Tidal volume + inspiratory reserve volume (avg. 3L)

Question 10

What is the functional residual capacity

Answer 10

Expiratory reserve volume + residual volume (avg. 3L) – volume remaining after normal expiration

Question 11

What is the vital capacity

Answer 11

The inspiratory reserve volume + tidal volume + expiratory reserve volume, maximum exhalation after maximum inhaltion

Question 12

The lining of each alveolar is covered in water which poses a risk during expiration as the water molecules can become stuck to each other, we do not possess enough muscle power to overcome this tension
How do we overcome this

Answer 12

Surfactant is released from type 2 pneumocytes which reduces surface tension of water

Question 13

What factors affect airflow (Q)

Answer 13

Question 14

How does salbutamol treat asthma

Answer 14

Act as beta-2 receptor agonists to increase bronchodilation

Question 15

Role of beta 2 and M3 receptors on smooth muscle on bronchioles

Answer 15

When beta 2 is stimulated it results in muscle relaxation and bronchodilation - it is not innervated by sympathetic system so they are likely to respond to circulating catecholamines from adrenals

Acetylcholine is released from parasympathetic nervous system resulting in smooth muscle contraction

Question 16

What are the zones of the bronchial tree

Answer 16

Conducting zone (generations 1-16)
Transitional and respiratory zones (generations 17-23)