Final answer:
The most important facial muscle used in kissing is the orbicularis oris, which contracts to pucker the lips. The masseter muscle is involved in chewing, and the buccinator helps in pressing the cheeks against the teeth. The orbicularis oculi closes the eyes but is unrelated to kissing.
Step-by-step explanation:
The Orbicularis Oris Muscle and Kissing
The most important facial muscle used in kissing is the orbicularis oris. When we kiss, the orbicularis oris muscle, which is a circular muscle around the mouth, engages in a contraction that puckers the lips, allowing for this intimate gesture. It is part of a group of facial muscles that regulate the movements necessary for facial expressions, including those used in kissing.
In contrast, the masseter muscle is responsible for the action of chewing (b.), not kissing. It is one of the strongest muscles in the body and it elevates the mandible (lower jaw) to close the mouth during chewing. This muscle is not directly involved in the act of kissing, which primarily requires the fine movements controlled by the orbicularis oris.
The platysma and buccinator muscles are also mentioned but do not play a primary role in kissing. The platysma helps in lowering the mandible and tensing the skin of the neck, while the buccinator muscle assists in chewing by pressing the cheeks against the teeth. The orbicularis oculi is also a circular muscle, but it is responsible for closing the eyes, not for movements of the mouth used in kissing.