Axial Muscles Function, Bio 201

epicranius frontalis

raises eyebrows

epicranius occipitalis

fixes aponeurosis and pulls scalp posteriorly

orbicularis oculi

closes eyelid

levator palpebrae superioris

open upper eyelid

corrugator supercilli

draws eyebrows together and inferiorly (frown)

orbicularis oris

closes lips (kissing)

zygomaticus major

raises corner of mouth upwards (smiling)

buccinator

compresses cheek (whistling and trumping)

platysma

tenses skin of neck (growling/pouting)

superior rectus

extrinsic eye muscle; elevates eye and turns it medially

inferior rectus

extrinsic eye muscle; depresses eye and turns it medially

medial rectus

extrinsic eye muscle; moves eye medially

lateral rectus

extrinsic eye muscle; moves eye laterally

superior oblique

extrinsic eye muscle; depresses eye and turns it laterally

inferior oblique

extrinsic eye muscle; elevates eye and turns it laterally

temporalis

involved in chewing; closes jaw

masseter

involved in chewing; prime mover of jaw closure (chewing)

medial pterygoid

involved in chewing; aids in grinding movements of teeth

lateral pterygoid

involved in chewing; aids in grinding movements of teeth

tongue

speaking and chewing

sternocleidomastoid

flexes and laterally rotates head

splenius capitis

extend or hyperextend head

diaphragm

prime mover of inspiration

external intercostals

elevates rib cage; involved in respiration

internal intercostals

depresses rib cage; involved in respiration

scalenes

elevates ribs 1-2 (aid in inspiration)

external oblique

flex spine, rotate trunk, flex laterally, compress viscera

internal oblique

flex spine, rotate trunk, flex laterally, compress viscera

transverse abdominis

compresses abdominal contents

rectus abdominis

flexes and rotates vertebral column (sit-ups)

erector spinae

prime mover of spine extension

quadratus lumborum

flexes vertebral column laterally; core muscle that forms most of posterior abdominal wall and is most often “pulled”