Elastic properties of the lung and chest wall

Question 1

Elastic and compliance def

Answer 1

Resistance of an object to deformation by external force

The ability of an object to stretch. kinda the opposite of elasticity

High elasticity means low compliance, so hard to stretch and easy to recoil

Question 2

Pressure - volume curve for long

Answer 2

Question 3

Relationship between lung volume and compliance

Answer 3

Question 4

In terms of breathing…

Answer 4

Question 5

What determines compliance in the lungs

Answer 5

Elastic properties of tissue (connective tissue forces) and surface tension at air-water interfaces in alveoli

The alveoli are tiny sacs which have a tiny lining of fluid, and the air-liquid interface tension rises causing water molecules to pull towards each other, making the alveoli want to collapse, creating a force that resists lung inflation.

Surfactant molecules strongly attract to each other but not others, so they accumulate at the surface and reduce surface tension.

Without surfactant compliance would decrease a lot.

Question 6

Laplace’s Law

Answer 6

Question 7

Why dont smaller alveoli collapse into larger alveoli

Answer 7