Multiple choice

What is/are the reason(s) for increase in the volume of thoracic cavity?

  1. Contraction of intercostal and rib muscles

  2. Contraction of diaphragm

  3. Lowering of pressure inside the lungs

  4. Both (1) and (2)

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Increase in the volume of thoracic cavity is both due to contraction of intercostal/rib muscles and diaphragm.