Muscles of Upper Extremity

Question 1

Pectoralis Major

Answer 1

O: Clavicular head - medial half of clavicle, Sternocostal head: sternum, superior costal cartilages

I: Lateral lip of intertubercular sulcus of humerus

Innervation: Clavicular head: lateral pectoral nerve, Sternocostal head: medial pectoral nerve

A: adduct and medially rotate arm; flex clavicular head

Question 2

Pectoralis minor

Answer 2

O: ribs 3-5

I: coracoid process of scapula

Innervation: medial pectoral nerve

A: stabilize scapula

Question 3

Subclavius

Answer 3

O: Rib 1

I: subclavian groove on inferior clavicle

Innervation: nerve to subclavius

A: depress clavicle

Question 4

Deltoid

Answer 4

O: spine of scapula, acromion, lateral third of clavicle

I: deltoid tuberosity of humerus

Innervation: axillary nerve

A: Spinal part - extension and lateral rotation, Clavicular part - flexion and medial rotation, Acromial part - abduction of arm

Question 5

Teres Major

Answer 5

O: posterior surface of inferior angle

I: medial lip of intertubercular sulcus of humerus

Innervation: lower subscapular nerve

A: Adduction and medial rotation of arm

Question 6

Supraspinatus

Answer 6

ROTATOR CUFF
O: supraspinous fossa of scapula

I: greater tubercle of humerus

Innervation: suprascapular nerve

A: initiates abduction of arm up to 15 degrees, stabilize glenohumeral joint

Question 7

Infraspinatus

Answer 7

ROTATOR CUFF
O: Infraspinous fossa of scapula

I: greater tubercle of humerus

Innervation: suprascapular nerve

A: laterally rotate arm, stabilize glenohumeral joint

Question 8

Teres minor

Answer 8

ROTATOR CUFF
O: middle part of lateral border of scapula

I: greater tubercle of humerus

Innervation: axillary nerve

A: laterally rotate arm, stabilize glenohumeral joint

Question 9

Subscapularis

Answer 9

ROTATOR CUFF
O: subscapular fossa of scapula

I: lesser tubercle of humerus

Innervation: upper, lower scapular nerves

A: medially rotate and adduct arm, stabilize glenohumeral joint

Question 10

Serratus Anterior

Answer 10

O: Ribs 1-8

I: Inferior Angle and medial border of scapula

Innervation: Long Thoracic Nerve

Action: Primary glenoid-up rotator of scapula; Anchors scapula to thoracic wall by protracting & depressing scapula

Question 11

Biceps Brachii

Answer 11

O: Long head- supraglenoid tubercle, Short head - coracoid process

I: radial tuberocity, bicipital aponeurosis

Innv: musculocutaneous nerve

Question 12

Coracobrachialis

Answer 12

O: coracoid process

I: medial surface of mid-shaft of humerus

Innv: musculocutaneous nerve

Question 13

Brachialis

Answer 13

O: distal half of anterior humerus

I: coronoid process and tuberosity of ulna

Innv: musculocutaneous nerve

Question 14

Pronator teres

Answer 14

O: medial epicondyle of humerus, coronoid process of ulna

I: lateral surface of radius

Innv: median nerve

Question 15

Flexor carpi radialis

Answer 15

O: medial epicondyle of humerus

I: base of 2nd metacarpal

Innv: median nerve

Question 16

palmaris longus

Answer 16

O: medial epicondule of humerus

I: palmar aponeurosis

Innv: median nerve

Question 17

flexor digitorum superficialis

Answer 17

O: medial epicondyle of humerus, coronoid process, shaft of radius

I: middle phalanges of digits 2-5

Innv: median nerve

Question 18

flexor pollicis longus

Answer 18

O: radius, interosseous membrane

I: distal phalanx of digit 1

Innv: median nerve

Question 19

flexor carpi ulnaris

Answer 19

O: medial epicondyle of humerus, olecranon process of ulna

I: pisiform, hook of hamate, base of 5th metacarpal

Innv: ulnar nerve

Question 20

flexor digitorum profundus

Answer 20

O: ulna, interosseous membrane

I: distal phalanges of 2-5

Innv: lateral 1/2- median nerve, medial 1/2- ulnar nerve

Question 21

pronator quadratus

Answer 21

O: distal anterior ulna

I: distal anterior radius

Innv.: median nerve