Muscles to Know

Question 1

brachialis

Answer 1

origin: 1/2 way down the humerus; lateral and medial side

insertion: proximal ulna

action: flex elbow

Question 2

flexor digitorum profundus

Answer 2

origin: proximal ulna and lateral interosseous membrane

insertion: distal phalanges

action: flex fingers and hand

Question 3

flexor pollicis longus

Answer 3

origin: 1/3 down radius on lateral side interosseous membrane

insertion: distal thumb

action: flex thumb

Question 4

subscapularis(part of rotator cuff)

Answer 4

origin: subscapular fossa

insertion: lesser tuberosity of the humerus

action: flex and stabilize humerus

Question 5

supraspinatus(part of rotator cuff)

Answer 5

origin: supraspinatus fossa

insertion: superior part of greater tuberosity

action: elevates the proximal humerus

Question 6

infraspinatus(part of rotator cuff)

Answer 6

origin: infraspinatus fossa(part of the rotator cuff)

insertion: posterior on greater tuberosity(next to supraspinatus tendon)

action: pulls head of humerus backwards(extends shoulder)

Question 7

teres minor(part of rotator cuff)

Answer 7

origin: lateral margin of the scapula(2/3 way down from glenoid cavity)

insertion: inferior/posterior part of greater tuberosity

action: pulls humerus back and downwards(rotates posteriorly)

Question 8

triceps medial head(part of triceps)

Answer 8

origin: 1/3 way down dorsal part of the arm

insertion: olecrenon process

action: extends the arm

Question 9

triceps lateral head(part of the triceps)

Answer 9

origin: proximal and medial humerus

insertion: olecrenon process

action: extends the arm and rotates laterally

Question 10

triceps long head(part of the triceps)

Answer 10

origin: under the teres minor tendon

insertion: olecrenon process

action: extends elbow and shoulder

Question 11

biceps brachii(short head)

Answer 11

origin: coracoid process of the scapula

insertion: radial tuberosity of the radius

action: flex elbow and shoulder

Question 12

biceps brachii(long head)

Answer 12

origin: supraglenoid tuberosity of the scapula

insertion: radial tuberosity of the radius

action: flex elbow and shoulder

Question 13

pectoralis minor

Answer 13

origin: medial part of the ribs 3-5

insertion: coracoid process of the scapula

action: rotates/flexes shoulder

Question 14

rhomboid minor

Answer 14

origin: inferior portion of nuchal ligament

insertion: superior margin of the medial border of scapula

action: pull scapula back and upward(extend the shoulder)

Question 15

rhomboid major

Answer 15

origin: CT of spinous processes T1-T5 and nuchal ligament

insertion: medial border of scapula from spinous process down to inferior angle

action: pull scapula back and upward(extend the shoulder)

Question 16

levator scapula

Answer 16

origin: transverse processes if C2-C5 and nuchal ligament

insertion: medial border near superior angle

action: elevates the scapula

Question 17

pectoralis major(abdominal head)

Answer 17

origin: medial ribs(and cartilage) 4 and 5

insertion: proximal humerus, lateral edge of biceptal groove

action: power flex ion of humerus(downward motion)

Question 18

pectoralis major(sternocostal head)

Answer 18

origin: lateral border of sternum and cartilage of ribs 1-4

insertion: proximal humerus, lateral edge of biceptal groove(under abdominal head tendon)

action: abducts humerus(flex the shoulder)

Question 19

pectoralis major(clavicular head)

Answer 19

origin; inferior border of the clavicle(2/3 of it from medial side)

insertion: proximal humerus, lateral edge of biceptal groove(under sternocostalis head tendon)

action: flex humerus in and up

Question 20

latisssmus dorsi

Answer 20

origin: spinous processes of L1-L5, lumbodorsal fascia, medial part of iliac crest

insertion: proximal, ventral side of humerus

action: extends humerus(pulls arm down and back)