You notice that a patient's sternocleidomastoid and scalene muscles are contracting with respiration. What should you conclude based on this observance?
A) The patient is breathing normally, using the normal muscles of inspiration and expiration.
B) The patient is using his accessory muscles to exhale.
C) The patient is using his accessory muscles to inhale.
D) The patient is using the Hering-Breuer reflex to prevent lung overinflation.

Question

Quizplus · Accepted Answer

The sternocleidomastoid and scalene muscles are accessory muscles of respiration. They are used when there is increased demand for oxygen or the normal muscles of inspiration are unable to do their job effectively. In this case, the contraction of these muscles suggests that the patient is using them to help with inhalation, indicating that the patient is experiencing difficulty with breathing or has a respiratory condition that requires the use of accessory muscles.

You Notice That a Patient's Sternocleidomastoid and Scalene Muscles Are