Which muscle elevates the ribs during breathing and originates from the inferior border of each rib?

Which muscle elevates the ribs during breathing and originates from the inferior border of each rib?

• A. Latissimus Dorsi
• B. External Intercostals
• C. Internal Intercostals
• D. Serratus Anterior

Answer: (B)

Raising the ribs to expand the thoracic cavity during inhalation is a job for the external intercostal muscles. They originate from the inferior border of the rib above and insert on the superior border of the rib below, with fibers running downward and forward. When they contract, they pull the ribs upward, increasing thoracic volume to draw air into the lungs. The other options don’t fit this role: the latissimus dorsi is a back muscle involved in arm and trunk movements; the internal intercostals depress the ribs during forced expiration; and serratus anterior mainly moves the scapula and does not primarily elevate the ribs during breathing.

Raising the ribs to expand the thoracic cavity during inhalation is a job for the external intercostal muscles. They originate from the inferior border of the rib above and insert on the superior border of the rib below, with fibers running downward and forward. When they contract, they pull the ribs upward, increasing thoracic volume to draw air into the lungs. The other options don’t fit this role: the latissimus dorsi is a back muscle involved in arm and trunk movements; the internal intercostals depress the ribs during forced expiration; and serratus anterior mainly moves the scapula and does not primarily elevate the ribs during breathing.