Respiratory System: L4

Question 1

What forces allow expiration to occur passively at rest?

Answer 1

Elasticity (of the lung) and surface tension (in the lung)

Question 2

What is Elasticity?

Answer 2

Ability to recover the initial volume after inspiration based on physical properties.

The lungs are distensible.

Question 3

What proteins produce elasticity in the lungs?

Answer 3

Elastin and collagen.

Question 4

What is Surface Tension?

Answer 4

Molecules within a liquid have cohesive forces with all neighbouring atoms. But, those on the surface (i.e, at a liquid-gas interface) have no neighbouring atoms above, and so exhibit stronger attractive forces upon their nearest neighbours on the surface. This enhances of the. intermolecular attractive forces at the surface is called surface tension