Muscles: names and functions

Chapter 4: Muscular System

frontalis

raises eyebrows

orbicularis oculi

closes eyes

temporalis

moves ears slightly

buccinator

holds food between teeth when chewing

masseter

clenches teeth tightly

zygomatic

raises corner of mouth as in smiling

sternocleidomastoid

pulls head to one side, flexes neck or elevates sternum

trapezius

shrugs shoulders; rotates and moves scapula

platysma

draws angle of mouth downward when head leaned back

pectoralis major

raises upper arm adn pulls it across chest

rectus abdominis

pulls ribs and pelvis in; curves back as in doing crunches

external oblique

tenses abdominal wall and compresses abdominal contents

internal oblique

tenses abdominal wall and compresses abdominal contents

transverse abdominis

compresses abdomen

sartorius

longest muscle; flexes knee and hip, abducts and rotates thigh latterally

rectus femoris

extends knee

vastus lateralis

extends knee

vastus medialis

extends knee

adductor longus

adducts and flexes thigh

iliopsoas

flexes hip at thigh

pectineus

adducts flexes, and medially rotates thigh; primary function is hip flexion

gracilis

adducts thigh, flexes, and medially rotates leg; highest muscle inside thigh

gastrocnemius

points toes down; small muscle that works with gastrocnemius

soleus

points toes down; small muscle that works with gastrocnemius

tibialis anterior

flexes foot and raises toes

fibularis

plantar flexes and everts foot; helps keep foot flat on ground

deltoid

raises upper arm and pulls it slightly forward

triceps brachii

extends elbow and lower arm

biceps brachii

flexes elbow and lower arm and rotates hand palm up

brachioradialis

flexes lower arm when palm is down

extensor digitorum

extends finger

extensor carpi ulnaris

extends wrist and adducts hand

flexor carpi ulnaris

flexes wrist and adducts hand laterally

pectoralis major

raises upper arm and pulls it across chest

trapezius

shrugs shoulders; rotates and moves scapula

latissimus dorsi

lowers upper arm and pulls it back

deltoid

raises upper arm and pulls it slightly forward

triceps brachii

extends elbow and lower arm

gluteus maximus

extends thigh away from body at hip

gluteus medius

abducts and rotates thigh medially

semimembranosus

flexes knee, rotates lower leg medially and extends thigh

biceps femoris

flexes knee, rotates lower leg medially and extends thigh

semitendinosus

flexes knee, rotates lower leg medially and extends thigh

gastrocnemius

points toes down; flexes knee; large calf muscle