Muscles - Origin, Insertion, Action - Set I

Question 1

sternocleidomastoid origin

Answer 1

sternal head: anterior surface of manubrium

clavicular head: medial 1/3 of clavicle

Question 2

sternocleidomastoid insertion

Answer 2

mastoid process

lateral 1/2 of superior nuchal line

Question 3

sternocleidomastoid action

Answer 3

draws the mastoid process down toward the same side which causes the chin to turn up toward the opposite side

Question 4

deltoid origin

Answer 4

lateral 1/3 of clavicle
acromion
lower lip of the crest of the spine of the scapula

Question 5

deltoid insertion

Answer 5

deltoid tuberosity of the humerus

Question 6

deltoid action

Answer 6

abducts arm
anterior fibers flex and medially rotate
posterior fibers extend and laterally rotate

Question 7

biceps brachii origin

Answer 7

short head: tip of coracoid process of scapula

long head: supraglenoid tubercle of scapula

Question 8

biceps brachii insertion

Answer 8

tuberosity of the radius

Question 9

biceps brachii action

Answer 9

flexes forearm
flexes arm
supinates

Question 10

brachialis origin

Answer 10

anterior surface of the lower 1/2 of the humerus and the associated intermuscular septa

Question 11

brachialis insertion

Answer 11

coronoid process of the ulna

Question 12

brachialis action

Answer 12

flexes the forearm

Question 13

brachioradialis origin

Answer 13

upper 2/3 of the lateral supracondylar ridge of the humerus

Question 14

brachioradialis insertion

Answer 14

lateral side of the base of the styloid process of the radius

Question 15

brachioradialis action

Answer 15

flexes the elbow

assists in pronation and supination

Question 16

serratus anterior origin

Answer 16

ribs 1 through 8 or 9

Question 17

serratus anterior insertion

Answer 17

medial border of scapula on its costal (deep) surface

Question 18

serratus anterior action

Answer 18

draws the scapula forward

inferior fibers rotate the scapula superiorly

Question 19

pectoralis major origin

Answer 19

medial 1/2 of the clavicle
manubrium
body of sternum
costal cartilages of ribs 2-6
sometimes: rectus sheath of the upper abdominal wall

Question 20

pectoralis major insertion

Answer 20

crest of the greater tubercle of the humerus

Question 21

pectoralis major action

Answer 21

flexes and adducts arm

medially rotates arm

Question 22

trapezius origin

Answer 22

medial 1/3 of superior nuchal line
external occipital protuberance
ligamentum nuchae
spinous processes of vertebrae C7-T12

Question 23

trapezius insertion

Answer 23

clavicle
acromion scapular spine
tubercle of the scapular spine

Question 24

trapezius action

Answer 24

elevates and depresses the scapula
rotates scapula superiorly
retracts scapula

Question 25

gluteus maximus origin

Answer 25

posterior gluteal line posterior surface of sacrum and coccyx sacrotuberous ligament

Question 26

gluteus maximus insertion

Answer 26

gluteal tuberosity of the femur

Question 27

gluteus maximus action

Answer 27

extends the thigh | laterally rotates femus

Question 28

gluteus medius origin

Answer 28

external surface of the ilium between the posterior and anterior gluteal lines

Question 29

gluteus medius insertion

Answer 29

greater trochanter of the feumur

Question 30

gluteus medius action

Answer 30

abducts the femur | medially rotates the thigh