Upper Extremity Muscles

Question 1

What are the 4 muscles of the rotator cuff and which one initiates abduction?

Answer 1

1. Supraspinatus - initiates abduction of the arm
2. Infraspinatus
3. Subscapularis
4. Teres Minor

Question 2

What is the function, innervation, and blood supply of the pectoralis major?

Answer 2

Function: flexes and adducts arm, rotates it medially
Innervation: medial and lateral pectoral nerves
Blood supply: pectoral branch of thoracoacromial artery

Question 3

What is the function, innervation, and blood supply of the pectoralis minor?

Answer 3

Function: protracts the scapula
Innervation: medial pectoral nerve
Blood supply: pectoral branch of thoracoacromial artery

Question 4

What is the function, innervation, and blood supply of the deltoid?

Answer 4

Function: flexes and rotates arm
Innervation: axillary nerve
Blood supply: posterior circumflex humeral artery, deltoid branch of thoracoacromial artery

Question 5

What is the function, innervation, and blood supply of the infraspinatus?

Answer 5

Function: lateral rotation of the arm
Innervation: suprascapular nerve
Blood supply: subscapular artery

Question 6

What is the function, innervation, and blood supply of the subscapularis?

Answer 6

Function: medially rotates arm and adducts it
Innervation: upper and lower subscapular nerves
Blood supply: subscapular artery

Question 7

What is the function, innervation, and blood supply of the teres minor?

Answer 7

Function: laterally rotates the arm
Innervation: axillary nerve
Blood supply: circumflex scapular artery

Question 8

What is the function, innervation, and blood supply of the teres major?

Answer 8

Function: adducts and medially rotates the arm
Innervation: lower subscapular nerve
Blood supply: circumflex scapular artery

Question 9

What is the function, innervation, and blood supply of the biceps brachii?

Answer 9

Function: flexes and supinates forearm at elbow
Innervation: musculocutaneous nerve
Blood supply: muscular branches of brachial artery

Question 10

What is the function, innervation, and blood supply of the brachialis?

Answer 10

Function: flexes forearm at elbow
Innervation: musculocutaneous nerve and radial nerve
Blood supply: radial recurrent artery, muscular branches of brachial artery

Question 11

What is the function, innervation, and blood supply of the coracobrachialis?

Answer 11

Function: flexes and adducts arm at shoulder, allows you to put hat on
Innervation: musculocutaneous nerve
Blood supply: muscular branches of brachial artery

Question 12

What is the function, innervation, and blood supply of the triceps brachii?

Answer 12

Function: extends forearm at elbow
Innervation: radial nerve
Blood supply: branch of profunda brachii artery

Question 13

What is the function, innervation, and blood supply of the pronator teres?

Answer 13

Function: pronates the forearm and assists with elbow flexion
Innervation: median nerve
Blood supply: anterior ulnar recurrent artery

Question 14

What is the function, innervation, and blood supply of the flexor carpi radialis?

Answer 14

Function: flexes and abducts hand at wrist
Innervation: median nerve
Blood supply: radial artery

Question 15

What is the function, innervation, and blood supply of the flexor carpi ulnaris?

Answer 15

Function: flexes and adducts hand at wrist
Innervation: ulnar nerve
Blood supply: posterior ulnar recurrent artery

Question 16

What is the function and innervation of palmaris longus?

Answer 16

Function: flexes hand at wrist
Innervation: median nerve

Question 17

What is the function, innervation, and blood supply of the flexor digitorum superficialis?

Answer 17

Function: flexes middle and proximal phalanges of medial 4 digits, flexes hand at wrist
Innervation: median nerve
Blood supply: ulnar and radial arteries

Question 18

What is the function, innervation, and blood supply of the pronator quadratus?

Answer 18

Function: pronates forearm
Innervation: median nerve
Blood supply: anterior interosseous artery

Question 19

What is the function, innervation, and blood supply of the flexor digitorum profundus?

Answer 19

Function: flexes distal phalanges of medial 4 digits
Innervation: medial part = ulnar nerve, lateral part = median nerve
Blood supply: anterior interosseous artery

Question 20

What is the function, innervation, and blood supply of the flexor pollicis longus?

Answer 20

Function: flexes phalanges of thumb
Innervation: median nerve
Blood supply: anterior interosseous artery

Question 21

What is the function, innervation, and blood supply of the brachioradialis?

Answer 21

Function: weak flexion of forearm when mid-pronated
Innervation: radial nerve
Blood supply: radial recurrent artery

Question 22

What is the function, innervation, and blood supply of the extensor carpi radialis longus and brevis?

Answer 22

Function: extends and abducts hand at wrist
Innervation: radial nerve
Blood supply: radial recurrent artery

Question 23

What is the function, innervation, and blood supply of the extensor carpi ulnaris?

Answer 23

Function: extends and abducts hand at wrist
Innervation: radial nerve
Blood supply: posterior interosseous artery

Question 24

What is the function, innervation, and blood supply of the extensor digiti minimi and the extensor digitorum?

Answer 24

Function: extends 5th digit, extends medial 4 digits
Innervation: radial nerve
Blood supply: posterior interosseous artery

Question 25

What is the function, innervation, and blood supply of the abductor pollicis longus?

Answer 25

Function: abducts thumb
Innervation: median nerve
Blood supply: superficial palmar branch of radial artery

Question 26

What is the function, innervation, and blood supply of the extensor polllicis brevis?

Answer 26

Function: extends thumb
Innervation: radial nerve
Blood supply: posterior interosseous artery

Question 27

What is the function, innervation, and blood supply of the extensor pollicis longus?

Answer 27

Function: extends distal part of thumb at interphalangeal and metacarpophalangeal joints
Innervation: radial nerve
Blood supply: posterior interosseous artery

Question 28

What is the function, innervation, and blood supply of the extensor indices?

Answer 28

Function: extends 2nd digit
Innervation: radial nerve
Blood supply: posterior interosseous artery

Question 29

What is the function, innervation, and blood supply of the opponens pollicis?

Answer 29

Function: draws 1st metacarpal forward and rotates it medially
Innervation: median nerve
Blood supply: superficial palmar branch of radial artery

Question 30

What is the function, innervation, and blood supply of the abductor pollicis brevis?

Answer 30

Function: abducts thumb
Innervation: median nerve
Blood supply: deep palmar branch of ulnar artery

Question 31

What is the function, innervation, and blood supply of the flexor pollicis brevis?

Answer 31

Function: flexes proximal phalanx of thumb
Innervation: median nerve
Blood supply: superficial palmar branch of radial artery

Question 32

What is the function, innervation, and blood supply of the abductor digiti minimi?

Answer 32

Function: abducts little finger
Innervation: ulnar nerve
Blood supply: deep palmar branch of ulnar artery

Question 33

What is the function, innervation, and blood supply of the flexor digiti minimi?

Answer 33

Function: flexes proximal phalanx of little finger
Innervation: ulnar nerve
Blood supply: deep palmar branch of ulnar artery

Question 34

What is the function, innervation, and blood supply of the adductor pollicis?

Answer 34

Function: adducts thumb
Innervation: ulnar nerve
Blood supply: deep palmar arch

Question 35

What do the lumbricals do, what is their innervation and what is their blood supply?

Answer 35

Function: extends digits at interphalangeal joints, flexion
Innervation: lateral lumbricals -> median nerve; medial lumbricals -> ulnar nerve
Blood supply: superficial and deep palmar arches

Question 36

What is the function, innervation, and blood supply of the dorsal interossei?

Answer 36

Function: abducts digits from axial line of hand
Innervation: ulnar nerve
Blood supply: deep palmar arch

Question 37

What is the function, innervation, and blood supply of the palmar interosseous muscles?

Answer 37

Function: adducts digits toward axial line of hand (3rd digit)
Innervation: ulnar nerve
Blood supply: deep palmar arch