Final answer:
The masseter, temporalis, and medial pterygoid muscles work together to close the jaw during chewing by elevating and moving the mandible. The masseter is the main muscle responsible, assisted by the temporalis muscle, while the medial pterygoid aids in moving the jaw from side to side.
Step-by-step explanation:
The coordinated function of the masseter, temporalis, and medial pterygoid muscles is essential for closing the jaw during mastication (chewing). The masseter muscle is the primary muscle used for chewing as it elevates the mandible (lower jaw) to close the mouth. The temporalis muscle assists the masseter by retracting the mandible. Meanwhile, the medial pterygoid muscle moves the mandible from side to side, helping in the overall process of chewing and breaking food into smaller, digestible pieces.