In the context of muscle actions, what is the primary function of the masseter muscle?

• A. Elevates the mandible to close the jaw (jaw closure during chewing)
• B. Protracts the tongue to aid in swallowing
• C. Depresses the mandible to open the jaw
• D. Elevates the hyoid bone during swallowing

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the anatomical location and general function of the masseter muscle. The masseter is one of the main muscles involved in mastication (chewing) and is located on the side of the face, connecting the zygomatic arch to the mandible.
2. Step 2: Recall the primary actions of the masseter muscle. It is a powerful muscle that primarily acts to move the mandible, specifically focusing on elevating it.
3. Step 3: Differentiate between the possible actions listed: elevating the mandible (closing the jaw), protracting the tongue, depressing the mandible (opening the jaw), and elevating the hyoid bone. Consider which of these actions are related to the masseter's anatomical attachments and function.
4. Step 4: Recognize that elevating the mandible to close the jaw is the key function of the masseter muscle, which is essential during chewing to bring the teeth together.
5. Step 5: Conclude that the masseter muscle's primary function is to elevate the mandible, enabling jaw closure during chewing, and that the other options involve different muscles or actions.