MCB 150 Lecture 7: Muscles of facial expressions

• School: University of Illinois
• Department: Molecular and Cell Biology
• Course: MCB 150
• Professor: B Mehrtens

Document Summary

Know the names, locations, and actions of muscles responsible for these functions: Epicranius: composed of occipitofrontalis muscle & epicranial aponeurosis. Frontal belly of occipitofrontalis: raises eyebrows & wrinkles skin of forehead. Corrugator supercilii: draws eyebrows together & forms vertical wrinkle lines around nose. Orbicularis oculi: eyelid closes-when wink, blink or squint. Levator palpebrae superioris: elevates upper eyelid when open eyes. Orbicularis oris: close mouth, pucker up for a kiss. Depressor labii inferioris: pulls lower lip inferiorly. Depressor anguli oris: frown muscle-pulls corners of mouth inferiorly. Levator labii superioris: pulls upper lip superiorly. Levator anguli oris: pulls corners of mouth superiorly & laterally. Works with zygomaticus major & minor when you smile. Risorius: pulls corner of lips laterally-closed mouth smile. Platysma: tenses skin of neck & pulls lower lip inferiorly. Buccinator: compresses cheek against the teeth when we chew. Medial pterygoid - elevates and protracts mandible, produces side-to-side movement of mandible. Lateral pterygoid - protracts mandible, produces side-to-side movement of mandible.