skeletal muscles

ch. 11

frontalis

a: wrinkles forehead, raises eyebrows

orbicularis oculi

a: closes eye (blinking, winking)

zygomaticus minor

a: elevates corners of mouth (smiling, laughing)

zygomaticus major

a: elevates corners of mouth (smiling, laughing)

orbicularis oris

a: closes lips (kissing, whistling)

occipitalis

a: pulls scalp backwards

corrugator supercilii

a: makes vertical wrinkles of forehead

levator labii superioris

a: elevates upper lip

risorius

a: draws angles (corners of mouth) laterally (laughing or tenseness)

mentalis

a: protrudes lower lip

depressor labii inferioris

a: depresses lower lip

depressor anguli oris

a: depresses angles of the mouth

temporalis

a: closes jaw by elevating mandible

masseter

a: closes jaw by elevating mandible

buccinator

a: compresses cheeks (during eating, blowing, or sucking)

sternohyoid

a: depresses hyoid and larynx (the epiglottis will no longer cover the larynx and air can enter)

mylohyoid

a: elevates hyoid and larynx (so epiglottis can cover larynx during swallowing)

digastric

a: elevates hyoid and larynx (so epiglottis can cover larynx during swallowing)

sternocleidomastoid

a: 1. flexes the neck when muscles on both side are contracted

2. rotates the head toward opposite shoulder if only muscle on one side is contracted

o: clavicle and manubrium of sternum

i: mastoid process of temporal bone

deltoid

a: arm abduction

o: clavicle and spine of scapula

i: deltoid tuberosity of humerus

pectoralis major

a: arm flexion and arm adduction

subscapularis

a: rotates arm medially (inward)

latissimus dorsi

a: arm extension and arm adduction

supraspinatus

a: arm abduction

infraspinatus

a: rotates arm laterally (outward)

pectoralis minor

a: protracts scapula (pulls scapula forward)

serratus anterior

a: protracts scapula (pulls scapula forward)

trapezius

a: scapula elevation and scapula retraction

rectus abdominis

a: flexes and rotates lumbar region of vertebral column

o: pubic crest and pubic symphysis

i: xiphoid process of sternum

external oblique

a: 1. flex vertebral column (if both sides contracted)

2. trunk rotation and lateral flexion (if one side contracted)

internal oblique

a: 1. flex vertebral column (if both sides contracted)

2. trunk rotation and lateral flexion (if one side contracted)

transversus abdominis

a: compresses abdominal contents

biceps brachii

a: flexes and supinates the forearm; weakly flexes the arm

o: scapula (coracoid process and above glenoid cavity)

i: radial tuberosity of radius

brachioradialis

a: flexes forearm

o: distal humerus

i: styloid process of radius

brachialis

a: flexes forearm

o: distal humerus

i: coronoid process of ulna

triceps brachii

a: extends forearm at the elbow

o: scapula (below glenoid cavity) and humerus (posterior shaft)

i: olecranon process of ulna

anconeus

a: extends the forearm at the elbow

palmaris longus

a: tenses skin of palm during hand movement

flexor carpi ulnaris

a: flexes and adducts hand

flexor digitorum superficialis

a: flexes hand, fingers, and wrist

flexor carpi radialis

a: flexes and abducts hand

pronator teres

a: pronates forearm

flexor digitorum profundus

a: flexes wrist and fingers

extensor digitorum

a: extends digits and wrist

extensor carpi radialis brevis

a: extends and abducts wrist

extensor carpi radialis longus

a: extends and abducts wrist

extensor carpi ulnaris

a: extends and adducts wrist

supinator

a: supinates forearm

psoas major

a: 1. flexes thigh

2. flexes lumbar vertebral column

o: T₁₂ - L₅ vertebra

i: lesser trochanter

iliacus

a: 1. flexes thigh

2. flexes lumbar vertebral column

o: iliac crest and iliac fossa

i: lesser trochanter

sartorius

a: 1. flexion, abduction, and lateral rotation of thigh

2. flexion of leg

tensor fasciae latae

a: flexes and abducts thigh

rectus femoris

a: flexes thigh and extends leg

o: ilium and above acetabulum

i: patella and tibial tuberosity

vastus lateralis

a: extends leg

vastus medialis

a: extends leg

pectineus

a: adducts, flexes, and medially rotates thigh

adductor longus

a: adducts, flexes, and medially rotates thigh

gracilis

a: adducts thigh and flexes leg

gluteus medius

a: abduction and medial rotation of thigh

gluteus maximus

a: extension and lateral rotation of thigh

o: posterior ilium, sacrum, and coccyx

i: proximal femur and iliotibial tract

semimembranosus

a: extends thigh and flexes leg

semitendinosus

a: extends thigh and flexes leg

biceps femoris

a: extends thigh and flexes leg

tibialis anterior

a: dorsiflexion of the foot

extensor digitorum longus

a: extends digits 2-5 and dorsiflexes foot

extensor hallucis longus

a: extends big toe and dorsiflexes foot

fibularis longus

a: plantar flexion and foot eversion

fibularis brevis

a: plantar flexion and foot eversion

gastrocnemius

a: plantar flexion and leg flexion

o: medial and lateral condyles of femur

i: calcaneus

soleus

a: plantar flexion

popliteus

a: leg flexion

flexor digitorum longus

a: flexes digits 2-5 and plantar flexion

flexor hallucis longus

a: flexes big toe and plantar flexion

tibialis posterior

a: foot inversion and plantar flexion