Muscles And Nerve Innervation Of Facial Expression

The buccinator muscle is responsible for pressing the cheek against the teeth. It is innervated by the facial nerve VII. This muscle helps in actions such as blowing, sucking, and chewing. It also plays a role in keeping food in the oral cavity while eating and prevents it from getting stuck between the teeth and cheek.

The orbicularis oris muscle is responsible for closing the lips and also has the ability to protrude the lips. It is controlled by the facial nerve VII.

The muscle that elevates the eyebrows and wrinkles the forehead is called the frontalis. It is innervated by the Facial Nerve VII. This muscle is responsible for various facial expressions, such as surprise or concern, by raising the eyebrows and creating wrinkles on the forehead.

The orbicularis oculi is a sphincter muscle that is responsible for closing the eyelid. It is innervated by the Facial Nerve VII. When this muscle contracts, it causes the eyelid to close, protecting the eye from external stimuli such as dust or bright light.

The muscle that raises and protrudes the upper lip is called the levator labii superioris. This muscle is part of the facial VII nerve, which controls the muscles of facial expression. When this muscle contracts, it lifts the upper lip, creating a smiling or snarling expression.

The zygomaticus major muscle is responsible for drawing the angle of the mouth up and back, which is commonly associated with the action of laughing. This muscle is innervated by the Facial Nerve VII.

The depressor labii inferioris is a muscle that works together with the platysma to depress the lower lip. It is innervated by the Facial Nerve VII.

The occipitalis muscle is responsible for assisting the frontalis muscle in wrinkling the forehead. The occipitalis muscle is located at the back of the head and is connected to the frontalis muscle through a fibrous tissue called the galea aponeurotica. When the occipitalis muscle contracts, it helps to pull the galea aponeurotica, which in turn causes the frontalis muscle to contract and create wrinkles on the forehead. This muscle is innervated by the Facial Nerve VII.

The muscle that raises the upper eyelid is called the levator palpebrae superioris. This muscle is innervated by the oculomotor nerve (cranial nerve III). When this muscle contracts, it lifts the upper eyelid, allowing for better vision and opening of the eye.

The platysma muscle is responsible for drawing the lower lip and corner of the mouth inferiolaterally. It is innervated by the Facial Nerve VII.