Physiology 1

Question 1

Boyle’s law

Answer 1

At any constant temperature the
pressure exerted by a gas varies
inversely with the volume of the gas

Question 2

Intra-alveolar pressure

Answer 2

Intra-alveolar pressure = 760
Intra-pleural = 756
Atmospheric = 760

Question 3

What causes the lungs to recoil during expiration?

Answer 3

Elastic connective tissue

Alveolar surface tension

Question 4

LaPlace’s law

Answer 4

The smaller the alveoli, the more likely they are to collapse
(surfactant lowers surface tension of smaller alveoli and prevents them collapsing)

Question 5

Forces keeping the alveoli open

Answer 5

Transmural pressure gradient
Pulmonary surfactant
Alveolar interdependence

Question 6

Forces promoting alveolar collapse

Answer 6

Elasticity of stretched pulmonary connective tissue fibres

Alveolar surface tension