Stephanie Britton: muscles of facial expression https://youtu.be/ytOUkuOtuqI

Occipitofrontalis, two muscles, front and back, that pull the scalp back and raise the eyebrows.

Orbicularis oculi, sphincter around the eye. Origin at the medial point near the nose. Insertion all around the circle. as the insertion points pulled towards the origin the eye closes.

Orbicularis Oris, sphincter around the mouth. Puckers the lips. Four quadrants. Origin points in the center under the nose. Insertion at the outside corners. As the insertion points are pulled towards the origins the lips Pucker. All origin and insertion points are in the soft tissue only, not bone.

Zygomaticus major. Origin on the zygomatic bone, the cheekbone. Insertion in the skin at the corner of the lips. Elevates the corner of the lips. Pulls the lips into a smile.

Platysma. (Platy = flat, broad) a large sheet covering the neck from the Jaw to the clavicle. Origin on the clavicle. insertion points on the mandible and on the skin of the chin. Depresses the mandible. Depresses the corners of the lips. Makes a grimace. Chords pop out of the neck.

Nasalis Upper region compresses the bridge of the nose. Lower region flares the nostrils.

Buccinator. (Bucks in ate or) compresses the cheeks against the teeth. Used when whistling or sucking air inwards.

Stephanie Britton: Muscles of mastication https://youtu.be/y9NC-tCkJyA

Temporalis. On the temle. Origin at the temple bone. Insertion in the mandible. Elevates the mandible. Pulls the jaw up.

Masseter. In the cheeks. Origin on the zygomatic bone. Insertion on the Angle and ramus, parts of the mandible. Elevates the mandible.

Medial Pterygoid. Origin on the zygomatic bone. Insertion on the inside of the ramus. Elevates the mandible, and moves it side to side.

Medial Pterygoid. Origin on the skull. Insertion on the back of the upper mandible. Push mandible forward. And move mandible side to side.