Muscles of the Upper Extremity

Question 1

Pectoralis Major

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 1

1) Clavicular head: medial 1/2 clavicle
Sternocostal head: anterior surface of the sternum, costal cartilages

2) Lateral edge of intertubercular groove of humerus
3) Adduct and medially rotate the humerus, protracts and depresses the scapula; clavicular head flexes humerus; sternocostal head extends humerus from flexed state
4) Lateral and medial pectoral nerve

Question 2

Pectoralis Minor

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 2

1) Medial aspect of ribs 3-5
2) Coracoid process of scapula
3) Stabilizes scapula by protracting and depressing it against the thoracic wall
4) Medial pectoral nerve

Question 3

Subclavius

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 3

1) Upper border 1st rib and 1st costal cartilage
2) Inferior aspect of the clavicle
3) Positions and depresses clavicle
4) Nerve to the subclavius

Question 4

Serratus Anterior

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 4

1) Lateral external surface of ribs 1-8
2) Anterior surface of medial border of scapula
3) Protracts the scapula, thereby stabilizing it against the thoracic wall, rotates the glenoid cavity superiorly
4) Long thoracic nerve

Question 5

Deltoid

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 5

1) Lateral 1/3 clavicle, scapular spine, acromion
2) Deltoid tuberosity of humerus
3) Anterior part flexes and medially rotates the humerus; middle part abducts the humerus; posterior part extends and laterally rotates the humerus
4) Axilary nerve

Question 6

Subscapularis

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 6

1) Medial aspect of the subscapular fossa
2) Lesser tubercle of humerus
3) Medially rotate and adduct the humerus, holds the humeral head in the glenoid cavity
4) Upper and lower subscapular nerve

Question 7

Supraspinatus

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 7

1) Supraspinous fossa of scapula
2) Greater tubercle of humerus
3) Abducts humerus, holds the humeral head in the glenoid cavity
4) Suprascapular nerve

Question 8

Infraspinatus

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 8

1) Infraspinous fossa of scapula
2) Greater tubercle of humerus
3) Laterally rotates humerus, holds the humeral head in the glenoid cavity
4) Suprascapular nerve

Question 9

Teres Minor

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 9

1) Middle part of the lateral border of scapula
2) Greater tubercle of humerus
3) Laterally rotates humerus, holds the humeral head in the glenoid cavity
4) Axillary nerve

Question 10

Teres Major

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 10

1) Posterior aspect of inferior angle of scapula
2) Medial edge of intertubercular groove of humerus
3) Adduct and medially rotate humerus
4) Lower subscapular nerve

Question 11

Biceps Brachii

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 11

1) Long head: supraglenoid tubercle of scapula
Short head: coracoid process of scapula

2) Radial tuberosity and antebrachial fascia as the bicipital aponeurosis
3) Flex humerus, flex the supine forearm, supinate the forearm; short head resists dislocation of the shoulder
4) Musculocutaneous nerve

Question 12

Coracobrachialis

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 12

1) Coracoid process
2) Medial aspect of the humeral body
3) Flex and adduct the humerus
4) Musculocutaneous nerve

Question 13

Brachialis

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 13

1) Distal half of the anterior aspect of the humeral body
2) Ulnar tuberosity and coronoid process
3) Flex forearm
4) Musculocutaneous nerve

Question 14

Triceps Brachii

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 14

1) Long head: infraglenoid tubercle of scapula
Lateral head: posterior aspect of the humeral body, superior to radial groove
Medial head: posterior aspect of humeral body, inferior to radial groove

2) Olecranon of ulna and antebrachial fascia
3) Extend the forearm, long head resists dislocation of the shoulder
4) Radial nerve

Question 15

Anconeus

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 15

1) Lateral humeral epicondyle
2) Lateral aspect of olecranon
3) Extends the forearm, stabilizes the elbow joint
4) Radial nerve

Question 16

What are the borders and contents of the triangular space?

Answer 16

Borders: teres minor/major and long head of the triceps brachii muscles

Contents: circumflex scapular artery and vein

Question 17

What are the borders and contents of the quadrangular space?

Answer 17

Borders: teres minor/major and long and lateral heads of the triceps brachii muscles

Contents: posterior humeral circumflex artery and vein, axillary nerve

Question 18

What are the borders and contents of the triangular interval?

Answer 18

Borders: teres major and long and lateral heads of the triceps brachii muscles

Contents: deep brachial artery and vein, radial nerve

Question 19

Pronator Teres

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 19

1) Humeral head: medial humeral epicondyle
Ulnar head: coronoid process of the ulna

2) Lateral aspect of the radius
3) Pronate and flex the forearm
4) Median nerve

Question 20

Flexor Carpi Radialis

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 20

1) Medial humeral epicondyle
2) Ventral aspect of the base of the 2nd metacarpal
3) Flex forearm, flex and abduct the hand at the wrist
4) Median nerve

Question 21

Palmaris Longus

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 21

1) Medial humeral epicondyle
2) Palmar aponeurosis, flexor retinaculum
3) Flex forearm, flex hand, and tenses the palmar aponeurosis
4) Median nerve

Question 22

Flexor Carpi Ulnaris

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 22

1) Humeral head: medial humeral epicondyle
Ulnar head: olecranon and posterior ulna

2) Pisiform, hook of hamate, and base of the 5th metacarpal
3) Flex forearm, flex and adduct the hand at the wrist
4) Ulnar nerve

Question 23

Flexor Digitorum Superficialis

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 23

1) Humeroulnar head: medial humeral epicondyle and coronoid process of the ulna
Radial head: superior half of anterior aspect of the radius

2) Bifed insertion on the intermediate phalanges of digits 2-5
3) Flex forearm, flex hand at the wrist, flex proximal and intermediate phalanges of digits 2-5 at the metacarpophalangeal and proximal interphalangeal joints
4) Median nerve

Question 24

Flexor Digitorum Profundus

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 24

1) Proximal ulna and interosseous membrane
2) Ventral aspect of bases of distal phalanges of digits 2-5
3) Flex hand at the wrist, flex all phalanges of digits 2-5 at the metacarpophalangeal, proximal, and distal interphalangeal joints

4) Lateral part: anterior interosseous nerve (of the median nerve)
Medial part: ulnar nerve

Question 25

Flexor Pollicis Longus

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 25

1) Anterior aspect of the radius and interosseous membrane
2) Ventral aspect of the base of distal phalanx of the pollux
3) Flex hand, flex and abduct 1st metacarpal at the 1st carpometacarpal joint, flex both phalanges of the pollux at the intercarpal joint
4) Anterior interosseous nerve (of the median nerve)

Question 26

Pronator Quadratus

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 26

1) Anterior aspect of the distal ulna
2) Anterior aspect of the distal radius
3) Pronate forearm, deep fibers hold the ulna and radius together
4) Anterior interosseous nerve (of the median nerve)

Question 27

Brachioradialis

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 27

1) Lateral humeral supracondylar ridge
2) Lateral aspect of the distal radius
3) Flex forearm (most force when forearm is midpronated)
4) Radial nerve

Question 28

Extensor Carpi Radialis Longus

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 28

1) Lateral humeral supracondylar ridge
2) Dorsal aspect of the base of the 2nd metacarpal
3) Extend and abduct the hand at the wrist (active during fist clenching)
4) Radial nerve

Question 29

Extensor Carpi Radialis Brevis

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 29

1) Lateral humeral epicondyle
2) Dorsal aspect of the base of the 3rd metacarpal
3) Extend and abduct the hand at the wrist
4) Deep radial nerve

Question 30

Extensor Digitorum

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 30

1) Lateral humeral epicondyle
2) Extensor expansions of digits 2-5
3) Extend hand at the wrist, extend all phalanges of digits 2-5 at the metacarpophalangeal, proximal, and distal interphalangeal joints
4) Posterior interosseous nerve

Question 31

Extensor Digiti Minimi

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 31

1) Lateral humeral epicondyle
2) Extensor expansion of digit 5
3) Extend all phalanges of digit 5 at the metacarpophalangeal, proximal, and distal interphalangeal joints
4) Posterior interosseous nerve

Question 32

Extensor Carpi Ulnaris

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 32

1) Lateral humeral epicondyle
2) Dorsal aspect of the base of the 5th metacarpal
3) Extend and adduct the hand at the wrist (active during fist clenching)
4) Posterior interosseous nerve

Question 33

Supinator

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 33

1) Lateral humeral epicondyle (plus a bunch of other crap)
2) Proximal aspect of the radial body
3) Supinate forearm
4) Deep radial nerve

Question 34

Extensor Indicis

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 34

1) Posterior aspect of the distal ulna and interosseous membrane
2) Extensor expansion of digit 2
3) Extend hand at the wrist and extend 2nd digit
4) Posterior interosseous nerve

Question 35

Abductor Pollicis Longus

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 35

1) Posterior aspect of the proximal ulna, radius, and interosseous membrane
2) Base of the 1st metacarpal
3) Abduct hand at the wrist, abduct the pollux at the carpometacarpal joint
4) Posterior interosseous nerve

Question 36

Extensor Pollicis Longus

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 36

1) Posterior aspect of ulna and interosseous membrane
2) Dorsal aspect of the base of the distal phalanx of the pollux
3) Abduct hand at the wrist, extend 1st metacarpal, proximal, and distal phalanges of the pollux at the carpometacarpal, metacarpophalangeal, and interphalangeal joints
4) Posterior interosseous nerve

Question 37

Extensor Pollicis Brevis

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 37

1) Posterior aspect of radius and interosseous membrane
2) Dorsal aspect of the base of the proximal phalanx of the pollux
3) Abduct hand, extend 1st metacarpal and proximal phalanges of the pollux at the carpometacarpal and metacarpophalangeal joints
4) Posterior interosseous nerve

Question 38

What is the lateral/medial border of the anatomical snuff box and what are its contents?

Answer 38

Lateral (anterior) Border: Abductor pollicis longus and extensor pollicis brevis muscles

Medial (posterior) Border: Extensor pollicis longus muscle

Contents: Radial artery (deep to tendons) and superficial radial nerve (superficial to tendons)

Question 39

Abductor Pollicis Brevis

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 39

1) Tubercles of the scaphoid and trapezium and the flexor retinaculum
2) Lateral aspect of the base of the proximal phalanx of the pollux
3) Abduct pollux, aids in opposition
4) Recurrent branch of the median nerve

Question 40

Opponens Pollicis

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 40

1) Tubercles of the scaphoid and trapezium and the flexor retinaculum
2) Lateral aspect of the 1st metacarpal
3) Oppose pollux
4) Recurrent branch of the median nerve

Question 41

Flexor Pollicis Brevis

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 41

1) Tubercles of the scaphoid and trapezium and the flexor retinaculum
2) Lateral aspect of the base of the proximal phalanx of the pollux
3) Flex 1st metacarpal and proximal phalanges of the pollux at the carpometacarpal and metacarpophalangeal joints

4) Superficial head: recurrent branch of the median nerve
Deep head: deep ulnar nerve

Question 42

Adductor Pollicis

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 42

1) Oblique head: capitate and bases of 2nd/3rd metacarpals
Transverse head: anterior aspect of the body of the 3rd metacarpal

2) Medial aspect of the proximal phalanx of the pollux
3) Adduct pollux
4) Deep ulnar nerve

Question 43

Abductor Digiti Minimi

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 43

1) Pisiform
2) Medial aspect of the base of the proximal phalanx of 5th digit
3) Abduct 5th digit
4) Deep ulnar nerve

Question 44

Flexor Digiti Minimi Brevis

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 44

1) Hook of hamate and flexor retinaculum
2) Medial aspect of the base of the proximal phalanx of 5th digit
3) Flex proximal phalanx of 5th digit
4) Deep ulnar nerve

Question 45

Opponens Digiti Minimi

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 45

1) Hook of hamate and flexor retinaculum
2) Medial aspect of the 5th metacarpal
3) Oppose 5th digit
4) Deep ulnar nerve

Question 46

1st and 2nd Lumbricals

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 46

1) Lateral side of the lateral 2 flexor digitorum profundus tendons as unipennate muscles
2) Radial aspect of the extensor expansions of the 2nd and 3rd digits
3) Flex proximal phalanges of the 2nd and 3rd digits at the metacarpophalangeal joint, extend intermediate and distal phalanges of the 2nd and 3rd digits by tightening extensor expansion
4) Median nerve

Question 47

3rd and 4th Lumbricals

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 47

1) Between the medial 3 flexor digitorum profundus tendons as bipennate muscles
2) Radial aspect of the extensor expansions of the 4th and 5th digits
3) Flex proximal phalanges of the 4th and 5th digits at the metacarpophalangeal joint, extend intermediate and distal phalanges of the 4th and 5th digits by tightening extensor expansion
4) Deep ulnar nerve

Question 48

Dorsal Interossei (1-4, DABs)

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 48

1) Adjacent sides of 2 metacarpals as a bipennate muscle
2) Bases of proximal phalanges and extensor expansion of digits 2-4
3) Abduct digits 2-4, flex proximal phalanges at the metacarpophalangeal joint, extend intermediate and distal phalanges by tightening extensor expansion
4) Deep ulnar nerve

Question 49

Palmar Interossei (1-3, PADs)

1) Origin
2) Insertion
3) Action
4) Innervation

Answer 49

1) Palmar aspect of the 2nd, 4th, and 5th metacarpals
2) Bases of proximal phalanges and extensor expansions of the 2nd, 4th, and 5th digits
3) Adduct 2nd, 4th, and 5th digits, flex proximal phalanges of the 2nd, 4th, and 5th digits at the metacarpophalangeal joint; extend intermediate and distal phalanges of the 2nd, 4th, and 5th digits by tightening extensor expansion
4) Deep ulnar nerve

Question 50

What are the 5 functional positions of the hand?

Answer 50

Power grip, hook grip, precision handling grip, pinching, and position of rest