The primary muscle(s) responsible for elevating the ribs during inspiration is (are)
A) the diaphragm.
B) the external intercostals.
C) the rectus abdominis.
D) the internal intercostals.
E) the erector spinae.

Question

Quizplus · Accepted Answer

The external intercostals are the primary muscles responsible for elevating the ribs during inspiration, as they contract to pull the ribs upward and outward, increasing the volume of the thoracic cavity and allowing air to flow into the lungs. The diaphragm also plays a role in inspiration, but its primary action is to contract and move downward, increasing the volume of the thoracic cavity and allowing the lungs to expand. The rectus abdominis, internal intercostals, and erector spinae are not involved in rib elevation during inspiration.

The Primary Muscle(s) Responsible for Elevating the Ribs During Inspiration