Upper Limb Muscles

Question 1

pectoralis major

Answer 1

origin: anterior surfaces of clavicle and sternum; costal cartilages of ribs 1-6; aponeurosis of external oblique muscle
insertion: lateral lip of inter tubercular sulcus of humerus
action: flex and adduct arm; rotate arm medially

blood supply: pectoral branch of thoracoacromial artery; perforating branches of internal thoracic artery

innervation: medial and lateral pectoral nerves

Question 2

pectoralis minor

Answer 2

origin: ribs 3-5 near costal cartilage
insertion: coracoid process of scapula
action: lowers lateral angle of scapula and protracts scapula

blood supply: pectoral branch of thoracoacromial artery

innervation: medial pectoral nerve

Question 3

subclavius

Answer 3

origin: junction of 1st rib and its costal cartilage
insertion: inferior surface of middle third of clavicle
action: anchor and depress clavicle

blood supply: clavicular branch of thoracoacromial artery

innervation: subclavian nerve

Question 4

serratus anterior

Answer 4

origin: lateral surfaces of ribs 1-8
insertion: anterior surface of medial border of scapula
action: protract and rotate scapula; hold scapula against thoracic wall

blood supply: lateral thoracic artery

innervation: long thoracic nerve

Question 5

deltoid

Answer 5

origin: lateral third of the clavicle; acromion; spine of scapula
insertion: deltoid tuberosity of the humerus

action:
clavicular- flexes and medially rotates shoulder joint
acromial- abducts shoulder joint (after 15 deg.)
spinal- extends and laterally rotates shoulder joint

blood supply: posterior circumflex humeral artery; deltoid branch of thoracoacromial artery

innervation: axillary nerve

Question 6

teres major

Answer 6

origin: posterior surface of the inferior angle of the scapula
insertion: medial lip of intertubercular sulcus of humerus
action: adducts and medially rotates shoulder joint

blood supply: circumflex scapular artery

innervation: lower subscapular nerve

Question 7

teres minor

Answer 7

origin: middle part of lateral border of scapula
insertion: inferior facet of greater tubercle of humerus
action: laterally rotate shoulder joint; help hold humeral head in glenoid cavity

blood supply: circumflex scapular artery

innervation: axillary nerve

rotator cuff muscle

Question 8

supraspinatous

Answer 8

origin: supraspinous fossa of scapula
insertion: superior facet of greater tubercle of humerus
action: initiate and assist deltoid with shoulder joint abduction

blood supply: suprascapular artery

innervation: suprascapular nerve

rotator cuff muscle

Question 9

infraspinatous

Answer 9

origin: infraspinous fossa of scapula
insertion: middle facet of greater tubercle of humerus
action: laterally rotate shoulder joint; help hold humeral head in glenoid cavity

blood supply: suprascapular artery

innervation: suprascapular nerve

rotator cuff muscle

Question 10

subscapularis

Answer 10

origin: subscapular fossa of scapula
insertion: lesser tubercle of humerus
action: medially rotate and adduct shoulder joint

blood supply: subscapular artery; lateral thoracic artery

innervation: upper and lower subscapular nerves

rotator cuff muscle

Question 11

biceps brachii

Answer 11

origin: short head- coracoid process of scapula; long head- supraglenoid tubercle of scapula
insertion: radial tuberosity
action: flex elbow joint; supination

blood supply: brachial a.

innervation: musculocutaneous n.

Question 12

brachialis

Answer 12

origin: middle part of anterior humerus
insertion: ulnar tuberosity
action: flex elbow joint in all positions

blood supply: brachial a.

innervation: musculocutaneous n.

Question 13

coracobrachialis

Answer 13

origin: coracoid process of scapula
insertion: middle third of medial surface of humerus
action: adduct arm; flex arm at shoulder joint

blood supply: brachial a.

innervation: musculocutaneous a.

Question 14

triceps brachii

Answer 14

origin: long head- infraglenoid tubercle of scapula; medial head- posterior surface of humerus, inferior to radial groove; lateral head- posterior surface of humerus, superior to radial groove
insertion: olecranon process
action: extend arm (long head), extend elbow

blood supply: deep brachial a.

innervation: radial n.

Question 15

pronator teres

Answer 15

origin: humeral head- medial epicondyle of humerus; ulnar head- coronoid process of ulna
insertion: middle of lateral surface of radius
action: pronate and flex forearm

blood supply: anterior ulnar recurrent artery

innervation: median nerve

Question 16

flexor carpi radialis

Answer 16

origin: medial epicondyle of humerus
insertion: base of 2nd metacarpal (index finger)
action: flex and abduct hand at wrist

blood supply: radial artery

innervation: median nerve

Question 17

palmaris longus

Answer 17

origin: medial epicondyle of humerus
insertion: distal half of flexor retinaculum
action: flex hand at wrist

blood supply: posterior ulnar recurrent artery

innervation: median nerve

Question 18

flexor carpi ulnaris

Answer 18

origin: olecranon and posterior border of ulna
insertion: pisiform and hook of hamate
action: flex and adduct hand at wrist

blood supply: posterior ulnar recurrent artery

innervation: ulnar nerve

Question 19

flexor digitorum superficialis

Answer 19

origin: humero-ulnar head- medial epicondyle of humerus and coronoid process of ulna; radial head- oblique line of radius
insertion: bodies of middle phalanges of fingers
action: flex wrist joint and make “girly fist” (can’t flex distal phalanges)

blood supply: ulnar and radial arteries

innervation: median nerve

Question 20

flexor digitorum profundus

Answer 20

origin: proximal 3/4 of medial and anterior surfaces of ulna
insertion: bases of distal phalanges
action: flex distal interphalangeal joints; flex wrist (make regular fist)

blood supply: anterior interosseous artery and ulnar artery

innervation: ulnar nerve (digits 4 and 5), median nerve (digits 2 and 3))

Question 21

flexor pollicis longus

Answer 21

origin: anterior surface of radius and interosseous membrane
insertion: base of distal phalange of thumb
action: flex wrist and thumb (bring thumb into fist)

blood supply: anterior interosseous artery

innervation: median nerve (anterior interosseous nerve)

Question 22

pronator quadratus

Answer 22

origin: distal 1/4 of anterior surface of ulna
insertion: distal 1/4 of anterior surface of radius
action: pronate forearm

blood supply: anterior interosseous artery

innervation: median nerve (anterior interosseous nerve)

Question 23

brachioradialis

Answer 23

origin: lateral supraepicondylar ridge of humerus
insertion: lateral surface of distal end of radius proximal to the styloid process
action: weak flexion of elbow; main flexor of elbow when forearm is pronated

blood supply: radial recurrent a.

innervation: radial n.

Question 24

extensor carpi radialis longus

Answer 24

origin: lateral epicondylar ridge of humerus
insertion: dorsal aspect of base of 2nd metacarpal
action: extend and abduct wrist

blood supply: radial a., radial recurrent a.

innervation: radial n.

Question 25

extensor carpi radialis brevis

Answer 25

origin: lateral epicondyle of humerus insertion: dorsal aspect of base of 3rd metacarpal action: extend and abduct wrist blood supply: radial a., radial recurrent a. innervation: radial n.

Question 26

extensor digitorum

Answer 26

origin: lateral epicondyle of humerus insertion: extensor expansions of medial 4 fingers action: extend wrist, extend fingers at metacarpophalangeal joints blood supply: posterior interosseous a. innervation: radial n. (posterior interosseous n.)

Question 27

extensor digiti minimi

Answer 27

origin: lateral epicondyle of humerus insertion: extensor expansion of 5th finger action: extend wrist, extend pinky at metacarpophalangeal joint blood supply: posterior interosseous a. innervation: radial n. (posterior interosseous n.)

Question 28

extensor carpi ulnaris

Answer 28

origin: lateral epicondyle of humerus, posterior border of ulna insertion: dorsal aspect of of base of 5th metacarpal action: extend and adduct wrist joint blood supply: posterior interosseous a. innervation: radial n. (posterior interosseous n.)

Question 29

supinator

Answer 29

origin: lateral epicondyle of humerus, crest of ulna, radial collateral and annular ligaments insertion: lateral, posterior, anterior surfaces of proximal 1/3 of radius action: supinate forearm blood supply: radial recurrent a., posterior interosseous a. innervation: radial n.

Question 30

abductor pollicis longus

Answer 30

origin: posterior surface of proximal 1/3 of ulna, radius, and interosseous membrane insertion: base of 1st metacarpal (thumb) action: extend wrist, abduct and extend thumb at carpometacarpal joint blood supply: posterior interosseous a. innervation: radial n. (posterior interosseous n.)

Question 31

extensor pollicis longus

Answer 31

origin: posterior surface of middle 1/3 of ulna and interosseous membrane insertion: dorsal aspect of base of distal phalanx of thumb action: extend wrist, extend distal phalanx of thumb blood supply: posterior interosseous a. innervation: radial n. (posterior interosseous n.)

Question 32

extensor pollicis brevis

Answer 32

origin: posterior surface of distal 1/3 of radius and interosseous membrane insertion: dorsal aspect of proximal phalanx of thumb action: extend wrist, extend proximal phalanx of thumb blood supply: posterior interosseous a. innervation: radial n. (posterior interosseous n.)

Question 33

extensor incidis

Answer 33

origin: posterior surface of distal 1/3 of ulna and interosseous membrane insertion: extensor expansion of 2nd finger (index) action: extend wrist, extend 2nd finger (index) blood supply: posterior interosseous a. innervation: radial n. (posterior interosseous n.)

Question 34

opponens pollicis

Answer 34

origin: flexor retinaculum and tubercles of scaphoid and trapezium insertion: lateral side of 1st metacarpal action: oppose thumb blood supply: radial a. (superficial palmar branch) innervation: recurrent branch of median nerve

Question 35

abductor pollicis brevis

Answer 35

origin: flexor retinaculum and tubercles of scaphoid and trapezium insertion: lateral side of base of proximal phalanx of thumb action: abduct thumb blood supply: radial a. (superficial palmar branch) innervation: recurrent branch of median nerve

Question 36

flexor pollicis brevis

Answer 36

origin: flexor retinaculum and tubercles of scaphoid and trapezium insertion: lateral side of base of proximal phalanx of thumb action: flex thumb blood supply: radial a. (superficial palmar branch) innervation: superficial head (recurrent branch of median nerve); deep head (deep branch of ulnar nerve)

Question 37

adductor pollicis

Answer 37

origin: oblique head- base of 2nd and 3rd metacarpals and capitate; transverse head- anterior surface of shaft of 3rd metacarpal insertion: medial side of base of proximal phalanx of thumb action: adduct thumb blood supply: deep palmar arch innervation: deep branch of ulnar nerve

Question 38

abductor digiti minimi

Answer 38

origin: pisiform insertion: medial side of base of proximal phalanx of 5th finger action: abduct 5th finger blood supply: deep palmar branch of ulnar artery innervation: deep branch of ulnar nerve

Question 39

flexor digiti minimi brevis

Answer 39

origin: hook of hamate and flexor retinaculum insertion: medial side of base of proximal phalanx of 5th finger action: flex proximal phalanx of 5th finger blood supply: deep palmar branch of ulnar artery innervation: deep branch of ulnar nerve

Question 40

opponens digiti minimi

Answer 40

origin: hook of hamate and flexor retinaculum insertion: medial border of 5th metacarpal action: brings pinky to opposition with the thumb blood supply: deep palmar branch of ulnar artery innervation: deep branch of ulnar nerve

Question 41

lumbricals

Answer 41

origin: 1 & 2- lateral 2 tendons of flexor digitorum profundus; 3 & 4- medial 3 tendons of flexor digitorum profundus insertion: lateral sides of extensor expansions of 2-5 fingers action: flex metacarpophalangeal joints and extend interphalangeal joints of fingers 2-5 blood supply: superficial and deep palmar arches innervation: median nerve (1 and 2), deep branch of ulnar nerve (3 and 4)

Question 42

dorsal interossei

Answer 42

origin: adjacent sides of 2 metacarpals insertion: lateral sides of extensor expansions of 2nd-5th fingers action: abduct 2-4 fingers from axial line; act with lumbricals blood supply: deep palmar arch innervation: deep branch of ulnar nerve

Question 43

palmar interossei

Answer 43

origin: palmar surfaces of 2, 4, 5 metacarpals insertion: bases of proximal phalanges; extensor expansions of 2, 4, 5 fingers action: adduct 2, 4, 5 fingers toward axial line; assist lumbricals blood supply: deep palmar arch innervation: deep branch of ulnar nerve