Contraction of These Muscles Depresses the Ribs During Forced Exhalation

Question

Contraction of these muscles depresses the ribs during forced exhalation.
A) external intercostals
B) scalenes
C) transversus thoracis
D) internal intercostals
E) serratus posterior inferior

Accepted Answer

Internal intercostals are the muscles responsible for depressing the ribs during forced exhalation. The other muscles listed either elevate the ribs (external intercostals) or aid in inspiration (scalenes, transversus thoracis, serratus posterior inferior).