Question

QUESTION 13

1. At FRC (functional residual capacity), the _________ elastic recoil of the lung is exactly balanced by the ____________ elastic recoil of the relaxed chest wall, and therefore FRC is the equilibrium volume for the lung-chest wall system.

   		a. outward, inward
   		b. inward, outward
   		c. inward, inward
   		d. outward, outward

Answer 1

Answer

At FRC (functional residual capacity), the inward elastic recoil of the lung is exactly balanced by the outward elastic recoil of the relaxed chest wall, and therefore FRC is the equilibrium volume for the lung-chest wall system.

• Fuctional residual capacity is the total amount of air remaining in lungs after normal, passive expiration.
• The lung tissue recoid inward and the chest wall has tendency to recoid outwards at rest.
• Both these forces balance at FRC to maintain the stability of lungs.

Option B) inward, outward