muscle function Flashcards
Orbicularis oris
Oral sphinchter
Nasalis
Transverse fibers compress & alar fibers widen the nasal aperature
Buccinator [L. bucca, cheek]
Compresses cheek
Levator labii superioris
Raises & everts upper lip
Levator anguli oris
Raises angle of the mouth
Zygomaticus major [G. zygon, yoke, a joining or pair]
Raises the buccal angle
Platysma [G. platys, flat, broad]
Wrinkles the anterior nuccal skin
Depressor anguli oris
Depresses buccal angle laterally
Depressor labii inferioris
Draws lower lip downward
Mentalis
Raises lower lip
Frontalis
Protracts the scalp or elevates eyebrows & nose
Orbicularis oculi
Palpebral sphinchter
Lateral rectus
Abduction of the eye
Inferior rectus [L. straight]
Depression, adduction & extorsion of eye
Inferior oblique
Elevation, abduction and extorsion of the eye
Medial rectus
Adduction of the eye
Levator palpebrae superioris
Elevation of the upper lid
Superior rectus
Elevation, adduction & intorsion of the eye
Superior oblique
Abduction, depression & intorsion of the eye
Temporalis
Elevation & retraction (posterior aspect of the muscle) of the mandible
Masseter
Elevation, protraction and retraction (deep fibers) the mandible
Lateral pterygoid
Protraction of the mandible & acts with the ipsilateral medial pterygoid to rotate the mandible to produce the side-to-side movements during trituration of food
Medial pterygoid
Elevation of the mandible & acts with the ipsilateral lateral pterygoid to rotate the mandible to produce the side-to-side movements during trituration of food
Sternocleidomastoid
Flexion of the head & neck, & contralateral rotation of the head
Omohyoid (G. omos, shoulder)
Depression of the hyoid
Sternohyoid
Depresses the hyoid
Sternothyroid
Depression of the elevated larynx
Posterior digastric
Depression of the mandible or elevation of the hyoid