At Which Point in the Respiratory Cycle is Thoracic Volume

Question

At which point in the respiratory cycle is thoracic volume the smallest?
A) At end-inhalation
B) With contraction of the diaphragm
C) With contraction of the external intercostals
D) At end of exhalation

Accepted Answer

At the end of exhalation, the thoracic volume is the smallest as the diaphragm and external intercostal muscles are relaxed, causing the lungs to deflate and the thoracic cavity to decrease in volume.