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 lower lip to and angles mouth downward.
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; Frontal belly
Origin: Epicranial aponeurosis
Insertion: Skin superior to supraorbital margin.
Action: Draws scalp anteriorly, raises eyebrows, and wrinkles skin of forehead horizontally as in look of surprise.
References:
Tortora, G. J., & Derrickson, B. (2017). Principles of anatomy and physiology (15th ed.). Wiley Custom Learning Solutions. https://handoutset.com/wp-content/uploads/2022/05/Principles-of-anatomy-and-physiology-Wiley-2017-Derrickson-Bryan-H._-Tortora-Gerard-J..pdf