What is the action of serratus posterior superior?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $9.99Unlock all

Enhance your understanding of back muscles with multiple choice questions and detailed explanations. Study the origin, insertion, action, and innervation of each muscle to get ready for your exam!

Multiple Choice

What is the action of serratus posterior superior?

Explanation:
The key idea is that serratus posterior superior acts as an accessory muscle of respiration. Its fibers pull the upper ribs upward when it contracts, specifically elevating ribs 2–5 to expand the thoracic cavity during inspiration. This action increases the thoracic volume to help with inhalation. It does not depress the ribs or extend or rotate the spine—the latter actions belong to other back muscles like the erector spinae and vertebral rotators. So elevating the ribs during respiration best describes its function.

The key idea is that serratus posterior superior acts as an accessory muscle of respiration. Its fibers pull the upper ribs upward when it contracts, specifically elevating ribs 2–5 to expand the thoracic cavity during inspiration. This action increases the thoracic volume to help with inhalation. It does not depress the ribs or extend or rotate the spine—the latter actions belong to other back muscles like the erector spinae and vertebral rotators. So elevating the ribs during respiration best describes its function.

More Multiple Choice Questions
Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy