Muscular System

orbicularis oculi

closes eye

buccinator

compresses cheek

Zygomaticus major

raises mouth corners (smiling)

Orbicularis oris

closing lips (kissing)

masseter

elevates mandible

temporalis

elevates mandible, closes jaw

scalenes

flex, laterally flex and rotate the head

sternocleidomastoid

flexion of head, rotate head towards shoulder

internal intercostal

draws ribs together to depress cage

diaphragm

prime mover of inhalation, flattens on contraction

serratus anterior

fix scapula, move arm from side to front of body

external oblique

compress abdominal wall, aid in trunk rotation

internal oblique

Twisting at waist; bending to the side

rectus abdominos

flexes and rotates vertebral column

transverse abdominis

compresses abdominal contents

trapezius

sitting up; flexion of trunk

levator scapulae

elevate scapula and rotate its inferior angle medially

deltoid

prime mover of arm adduction

supraspinatus

initiates adbuction of arm

infraspinatus

lateral rotation of arm

teres minor

lateral rotation of arm

teres major

extends, medially rotates and adducts arm

latissimus dorsi

prime mover of arm extension, adducts and medially rotates arm

pectoralis major

prime movement of arm flexion, adducts and medially rotates arm

subscapularis

medial rotation at shoulder

triceps brachii

powerful arm extensor

biceps brachii

powerful flexion and supination of forearm

brachioradialis

synergist in foramen flexion

vastus lateralis

extends leg and stabilizes knee

vastus intermedius

extends leg

vastus medialis

extends leg and stabilizes patella

rectus femoris

extends leg and flexes thigh

sartorius

flexes, abducts and laterally rotates thigh; flexes leg

gracilis

adducts thigh, flexes and medially rotates thigh

gluteus maximus

powerful thigh extender

adductor magnus

adducts and medially rotates and flex thigh

adductor longus

adduction and flexion of femur

bicep femoris

extends thigh and flexes leg

semitendinosus

extends thigh and flexes leg

semimembransous

extends thigh and flexes leg

gastrocnemius (medial + lateral head)

plantar flexes foot

soleus

plantar flexion

tibialis anterior

prime mover of dorsiflexion

flexor digitorum longus

flexes toes; plantar flexes and inverts foot

extensor digitorum longus

helps extend toes at metatarsophalangeal joints