Which of the following best describes the primary function of axial muscles?

• A. They store calcium for muscle contraction.
• B. They are responsible for voluntary control of facial expressions.
• C. They support and position the head, neck, and trunk.
• D. They move the limbs and appendages.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the term 'axial muscles'—these are muscles located along the central axis of the body, including the head, neck, and trunk. Their primary role is related to stabilizing and positioning these regions.
2. Step 2: Eliminate incorrect options by analyzing their relevance to axial muscles. For example, storing calcium for muscle contraction is a function of the sarcoplasmic reticulum within muscle cells, not specific to axial muscles.
3. Step 3: Consider the option about voluntary control of facial expressions. While facial muscles are involved in expressions, they are categorized as cranial muscles, not axial muscles.
4. Step 4: Evaluate the option about moving limbs and appendages. Limb movement is primarily controlled by appendicular muscles, not axial muscles.
5. Step 5: Conclude that the correct description of axial muscles is their role in supporting and positioning the head, neck, and trunk, as this aligns with their anatomical location and function.