1.
- Muscle: Platysma
- Origin: Fascia over deltoid and pectoralis major muscles.
- Insertion: Mandible, blends with muscles around angle of mouth, and skin of lower face.
- Action: Draws outer part of lower lip inferiorly and posteriorly as in pouting; depresses mandible.
2.
- Muscle: Mentalis
- Origin: Mandible.
- Insertion: Skin of chin.
- Action: Elevates and protrudes lower lip and pulls skin of chin up, as in pouting.
3.
- Muscle: Orbicularis oris
- Origin: Muscle fibers surrounding opening of mouth.
- Insertion: Skin at corner of mouth.
- Action: Closes and protrudes lips, as in kissing; compresses lips against teeth; and shapes lips during speech.
4.
- Muscle: Corrugator supercilii
- Origin: Medial end of superciliary arch of frontal bone.
- Insertion: Skin of eyebrow.
- Action: Draws eyebrow inferiorly and wrinkles skin of forehead vertically as in frowning.
5.
- Muscle: Orbicularis oculi
- Origin: Medial wall of orbit.
- Insertion: Circular path around orbit.
- Action: Closes eye.
6.
- Muscle: Occipitofrontalis
- Origin: Epicranial aponeurosis.
- Insertion: Skin superior to supraorbital margin.
- Action: Draws scalp anteriorly, raises eyebrows, and wrinkles skin of forehead horizontally as in look surprise.
Reference:
Tortora, G. J., & Derrickson, B. H. (2020). Principles of Anatomy and Physiology (16th ed., pp. 356–357). John Wiley & Sons, Inc.