Muscle Actions and Innervations

Question 1

Innervation of the trapezius

Answer 1

spinal accessory nerve (CNXI)

Question 2

Actions of the trapezius

Answer 2

• elevates, retracts, and depresses scapula
• extends neck
• superiorly rotates glenohumeral joint

Question 3

Innervation of the latissimus

Answer 3

thoracodorsal nerve

Question 4

Actions of the latissimus dorsi

Answer 4

• extension of glenohumeral joint
• medial rotation of glenohumeral joint
• adduction of glenohumeral joint

Question 5

Innervation of the rhomboids

Answer 5

dorsal scapular nerve

Question 6

Actions of the rhomboids

Answer 6

retraction and elevation of scapula

Question 7

Levator scapulae innervation

Answer 7

dorsal scapular nerve

Question 8

Actions of the levator scapulae

Answer 8

elevates scapula only

Question 9

Actions of the splenius capitis

Answer 9

bilateral: head extension

Question 10

actions of the splenius cervicis

Answer 10

unilateral: lateral flexion and rotation of head

Question 11

Erector spinae innervation

Answer 11

dorsal rami of spinal nerves

Question 12

Actions of erector spinae

Answer 12

chief extensor of the vertebral column

Question 13

Actions of the levator costarum

Answer 13

elevate ribs for deep inspiration

Question 14

Deltoid innervation

Answer 14

axillary nerve

Question 15

Actions of the deltoid

Answer 15

• flexion and medial rotation of glenohumeral joint
• abduction
• extension and lateral rotation of glenohumeral joint

Question 16

Supraspinatus innervation

Answer 16

suprascapular nerve

Question 17

supraspinatus actions

Answer 17

initiates first 15 degrees of abduction

Question 18

infraspinatus innervation

Answer 18

suprascapular nerve

Question 19

infraspinatus actions

Answer 19

laterally rotates glenhohumeral joint

Question 20

teres minor innervation

Answer 20

axiillary nerve

Question 21

teres minor actions

Answer 21

laterally rotates glenohumeral joint

Question 22

Subscapularis innervation

Answer 22

subscapular nerve (upper/lower)

Question 23

subscapularis actions

Answer 23

medially rotates glenohumeral joint

Question 24

Innervation of teres major

Answer 24

lower subscapular nerve

Question 25

Actions of teres major

Answer 25

- adduction | - medially rotates glenohumeral joint

Question 26

Innervation of serratus anterior

Answer 26

long thoracic nerve

Question 27

Actions of serratus anterior

Answer 27

abducts and rotates scapula upward

Question 28

Serratus posterior superior actions

Answer 28

elevates upper ribs

Question 29

serratus posterior inferior actions

Answer 29

pulls down lower ribs

Question 30

External intercostals actions

Answer 30

aids forced inspiration by elevating ribs

Question 31

Rectus capitis posterior major and minor actions

Answer 31

extends head and neck

Question 32

Obliqus capitis inferior actions

Answer 32

rotates head

Question 33

Obliqus capitis superior actions

Answer 33

- bilateral: extends neck | - unilateral: lateral flexion to same side

Question 34

Innervation of Gluteus maximus

Answer 34

inferior gluteal nerve

Question 35

actions of gluteus maximus

Answer 35

- extends thigh and trunk | - laterally rotates hip joint

Question 36

Innervation of gluteus medius and minimus

Answer 36

superior gluteal nerve

Question 37

Actions of gluteus medius and minimus

Answer 37

-abduct hip joint when contralateral lower limb is raised

Question 38

Actions of the piriformis

Answer 38

laterally rotates and abducts thigh

Question 39

Actions of the gemellus superior, obturator internus, gemellus inferior, quadratus femoris

Answer 39

laterally rotate thigh

Question 40

Actions of biceps femoris, semitendinosus, and semimembranosus

Answer 40

- extension of hip joint | - flexion of knee joint

Question 41

Gastrocnemius innervation

Answer 41

tibial nerve

Question 42

gastrocnemius actions

Answer 42

- plantar flexion of foot | - knee flexion

Question 43

Soleus innervation

Answer 43

tibial nerve

Question 44

soleus actions

Answer 44

plantar flexion of foot

Question 45

Innervation of tibialis posterior

Answer 45

tibial nerve

Question 46

Actions of the tibialis posterior

Answer 46

- inversion and assists in the plantar flexion of the foot at the ankle - major role in supporting the medial arch of the foot

Question 47

Innervation of flexor hallucis longus

Answer 47

tibial nerve

Question 48

Actions of the flexor hallucis longus

Answer 48

- inversion and assists in the plantar flexion of the foot at the ankle - flex the great toe

Question 49

Flexor digitorum longus innervation

Answer 49

tibial nerve

Question 50

Actions of the digitorum longus innervation

Answer 50

- inversion and assists in the plantar flexion of the foot at the ankle - flexion of phalanges

Question 51

Fibularis longus and brevis innervation

Answer 51

superficial fibular nerve

Question 52

Actions of the fibularis longus and brevis

Answer 52

foot eversion

Question 53

Triceps brachii long head actions

Answer 53

-extension of the arm at the shoulder, adduction of the arm at the shoulder, extension of the forearm at the elbow

Question 54

Triceps brachii innervation

Answer 54

radial nerve

Question 55

Actions of the triceps brachii lateral head

Answer 55

extension of the forearm at the elbow