Anatomy Lab Exam 4

muscles

Frontalis

raises eyebrows

Occipitalis

pulls scalp posteriorly

Orbicularis Oculi

closes eye

Orbicularis Oris

closes and protrudes lips (puckering lips for a kiss)

Buccinator

manipulates food during chewing, expels air through pursed lips

Zygomaticus major

pulls angle of mouth superiorly and laterally (smiling)

Zygomaticus minor

raises lateral portion of upper lip (smiling)

Platysma

depresses lower lip, depresses mandible, tenses skin of neck

What are all these considered?

muscles of facial expression

What are the masseter and temporalis considered as?

muscles of mastication, or chewing

Masseter

elevates mandible

Temporalis

elevates and retracts the mandible

Digastric (made of anterior and posterior belly)

depresses mandible, fixation of the hyoid bone during swallowing

Mylohyoid

elevates the hyoid bone and floor of mouth, assisting tongue to push food toward the pharynx

Sternohyoid

depresses hyoid bone and larynx

sternocleidomastoid

bilateral (together action) = flexes head (chin moves towards the chest)

Unilateral (individual action) = flex and rotate the head toward opposite side

Scalenes (anterior, middle, posterior). What os the blended (together action) and unilateral individual action?

Bilateral: flexes head when first rib is fixed, elevates rib cage with vertebral column during forced inspiration

Unilateral: rotates head laterally