Washington Master Esthetics Practice Exam

What is NOT a function of the posterior muscles?

1. Support body posture

2. Cause the heart to contract and relax

3. Facilitate movement of the limbs

4. Assist in breathing

The correct answer is: Cause the heart to contract and relax

The correct answer is identified as the function that does not pertain to the posterior muscles. The posterior muscles, primarily situated along the back of the body, play key roles in supporting posture, facilitating movement, and assisting in breathing. Specifically, these muscles help maintain an upright position by supporting the spine and enabling various movements, such as extending or rotating the torso. Additionally, they are involved in respiratory mechanics, particularly the muscles associated with the back and ribs, which support the expansion and contraction of the thoracic cavity during breathing. On the other hand, the contraction and relaxation of the heart are regulated by the cardiac muscles, which are distinct from skeletal muscles, including those found in the posterior. The heart functions on its own intrinsic rhythm through the electrical conduction system, independent of the skeletal musculature functions. Thus, the role of causing the heart to contract and relax is not related to any function of the posterior muscles.