Muscles & Actions

Question 1

Frontalis

Answer 1

Elevates eyebrows; wrinkles skin of forehead

Question 2

Orbicularis oculi

Answer 2

Closes eyes; assists in facial expression

Question 3

Orbicularis oris

Answer 3

Closes lips, purses and protrudes lips (kissing muscle)

Question 4

Styloglossus

Answer 4

Draws tongue superiorly and posteriorly

Question 5

Stylohyoid

Answer 5

Elevates and retracts hyoid bone

Question 6

Massester

Answer 6

Elevates mandible (during chewing)

Question 7

Platysma

Answer 7

Draws lower lip and angle of mouth downward

Question 8

Sternocleidomastoid

Answer 8

Flexes neck if both sides contract (bilateral action); laterally flexes neck and rotates head to opposite side if one one side contracts (unilateral)

Question 9

Sternothyroid

Answer 9

Depresses larynx; aids in singing low notes

Question 10

Quadratus lumborum

Answer 10

Extends lumbar spine if both sides contract; ipsilateral flexion if only one side contracts; aids respiration

Question 11

Erector spinae

Answer 11

Extend and laterally flex vertebral column; 3 parts (iliocostalis, longissimus, spinalis)

Question 12

Diaphragm

Answer 12

Contraction expands thoracic cavity and compresses abdominopelvic cavity

Question 13

External intercostal

Answer 13

Elevate and protract ribs, expanding the thoracic cavity

Question 14

Internal intercostal

Answer 14

Depress and retract ribs, compressing the thoracic cavity

Question 15

Rectus abdominis

“6 pack”

Answer 15

Flexes lumbar vertebral column; increases abdominal pressure

Question 16

Transverse abdominal

Answer 16

Compresses abdominal contents if both sides contract

Question 17

Internal abdominal oblique

Answer 17

Flexes vertebral column and increases abdominal pressure if both sides contract; ipsilateral rotation at waist if only one side contracts

Question 18

External abdominal oblique

Answer 18

Flexes vertebral column and increases abdominal pressure if both sides contract; contralateral rotation at waist if only one side contracts

Question 19

Lavator ani

Answer 19

Forms floor of pelvis, supports pelvic viscera

Question 20

Trapezius

Answer 20

Fixes scapula and shoulder during arm movements; retracts (adducts) scapula; specific fibers aid in lateral rotation, elevation & depression

Question 21

Rhomboideus major

Answer 21

Deep to trapezius; fixes scapula during arm movements; retracts (adducts) scapula

Question 22

Serratus anterior

Answer 22

Protracts (abducts) scapula; prime mover in all forward-reaching and pushing actions

Question 23

Pectoralis major

Answer 23

Flexes shoulder; adducts and medially rotates arm; horizontal flexion of arm

Question 24

Deltoid

Answer 24

Whole muscle abducts arm; specific fibers aid in rotation of the arm and flexion, extension, horizontal extension of the shoulder

Question 25

Latissimus dorsi

Answer 25

Extends shoulder; adducts and medially rotates arm

Question 26

Supraspinatus

Answer 26

Abducts arm

Question 27

Infraspinatus

Answer 27

Laterally rotates arm

Question 28

Teres minor

Answer 28

Laterally rotates and adducts arm

Question 29

Subscapularis

Answer 29

Medially rotates arm

Question 30

Biceps brachii

Answer 30

Flexes shoulder and elbow; supinates forearm

Question 31

Brachialis

Answer 31

Prime mover in elbow flexion

Question 32

Brachioradialis

Answer 32

Flexes elbow

Question 33

Pronator quadratus

Answer 33

Prime mover in forearm pronation

Question 34

Supinator

Answer 34

Supinates forearm

Question 35

Flexor carpi radialis

Answer 35

Flexes wrists; radial flexion of wrists

Question 36

Flexor carpi ulnaris

Answer 36

Flexes wrists; ulnar flexion of wrists

Question 37

Triceps brachii

Answer 37

Extends elbow; extends shoulder and adducts arm

Question 38

Extensor capri radialis longus

Answer 38

Flexes wrists; radial flexion of wrist

Question 39

Extensor capri ulnaris

Answer 39

Extends wrist; ulnar flexion of wrist

Question 40

Extensor digitorum

Answer 40

Extends wrist and fingers

Question 41

Iliacus

Answer 41

Flexes thigh or trunk at hip; balances trunk when sitting

Question 42

Psoas major

Answer 42

Flexes thigh or trunk at hip; balances trunk when sitting

Question 43

Iliopsoas

Answer 43

These two muscles joint to insert at the lesser trochanter and shaft of the femur via a common tendon

Question 44

Gluteus maximus

Answer 44

Extends and laterally rotates hip

Question 45

Adductor longus

Answer 45

Adducts and flexes hip

Question 46

Adductor magnus

Answer 46

Adducts and extends hip

Question 47

Gracilis

Answer 47

Adducts and flexes hip; flexes knee

Question 48

Rectus femoris

Answer 48

Flexes hip; extends knee

Question 49

Vastus laretalis

Answer 49

Extends knee

Question 50

Vastus medialis

Answer 50

Extends knee

Question 51

Vastus intermedius

Answer 51

Extends knee

Question 52

Sartorius

Answer 52

Abducts and laterally rotates hip; flexes knee and medially rotates lower leg to allow cross-legged position

Question 53

Biceps femoris

Answer 53

Extends hip; flexes knee; lateral rotation of lower leg

Question 54

Semitendinosus

Answer 54

Extends hip; flexes knee; medial rotation of lower leg

Question 55

Semimembranosus

Answer 55

Extends hip; flexes knee; medial rotation of lower leg

Question 56

Tibialis anterior

Answer 56

Dorsiflexes ankle; inverts foot

Question 57

Extensor hallucis longus

Answer 57

Extends great toe; dorsiflexes foot

Question 58

Gastrocnemius

Answer 58

Plantar flexes ankle; flexes knee

Question 59

Soleus

Answer 59

Plantar flexes ankle

Question 60

Tibialis posterior

Answer 60

Plantar flexes and inverts foot

Question 61

Popliteus

Answer 61

Medial rotation of lower leg; unlocks knee to allow flexion

Question 62

Fibularis brevis

Answer 62

Everts foot

Question 63

Fibularis longus

Answer 63

Plantar flexes and everts foot