Why is inspiration called as an active process and expiration as passive?

Asked by saradamahapatra9999 | 12th Jun, 2019, 02:13: PM

Expert Answer:

  • Inspiration is an active process whereas expiration is a passive process.
  • Inspiration occurs when the muscles of the diaphragm contract to increase the overall volume of the thoracic cavity.
  • As a result, the pressure inside the lungs is less as compared to the atmospheric pressure, i.e., there is a negative pressure in the lungs with respect to atmospheric pressure.
  • As the muscles use energy for contraction, inspiration is called active process.
  • During expiration, muscles of the diaphragm relax.  
  • The pressure inside the lungs becomes higher than the atmospheric pressure without the use of energy and the air gushes out of the lungs. Thus, expiration is a passive process. 

Answered by Sheetal Kolte | 12th Jun, 2019, 06:58: PM