1.
Muscle: Platysma
Origin: Fascia over deltoid and pectoralis major muscles
Insertion: Mandible
Action: Inferiorly and posteriorly draws outer part of lower lip and depresses mandible
2.
Muscle: Depressor labii inferioris
Origin: Mandible
Insertion: Angle of mouth
Action: Draws angle of mouth laterally and inferiorly, opens mouth
3.
Muscle: Orbicularis oris
Origin: Muscle fibers around the mouth
Insertion: Skin at corner of mouth
Action: Closes and protrudes lips, 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
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: Pulls scalp anteriorly, raises eyebrows, wrinkles forehead