Upper limb muscles

Question 1

Subclavius

Answer 1

origin: 1st rib
insertion: clavicle
innervation: nerve to subclavius
blood supply: thoracoacromial artery
action: depresses clavicle

Question 2

Subscapularis (Rotator cuff)

Answer 2

origin: subscapular fossa of scapula (anterior)
insertion: lesser tubercle of humerus
innervation: upper and lower subscapular nerves
blood supply: subscapular artery
action: medially rotates humerus

Question 3

Supraspinatous (rotator cuff)

Answer 3

origin: supraspinous fossa of scapula (posterior)
insertion: greater tubercle of humerus
innervation: suprascapular nerve
blood supply: suprascapular artery
action: initiates abduction of arm

Question 4

Infraspinatous (rotator cuff)

Answer 4

origin: infraspinous fossa of scapula (posterior)
insertion: greater tubercle
innervation: suprascapular nerve
blood supply: suprascapular artery
action: laterally rotates humerus

Question 5

Teres minor (rotator cuff)

Answer 5

origin: lateral border of scapula
insertion: greater tubercle
innervation: axillary nerve
blood supply: posterior circumflex humeral artery
action: laterally rotates humerus

Question 6

Deltoid

Answer 6

origin: spine, acromium of scapula + lateral 1/3 clavicle
insertion: deltoid tuberosity of humerus (mid shaft, anterolateral)
innervation: axillary nerve
blood supply: anterior and posterior circumflex humeral arteries
action: flexion, abduction, and extension of humerus

Question 7

Serratus anterior

Answer 7

origin: anterolateral ribs 1-8
insertion: anterior aspect of medial border of scapula
innervation: long thoracic nerve (C5-C7)
blood supply: lateral thoracic artery (2nd set of axillary)
action: abduction above shoulder height, scapula protraction

Question 8

Pectoralis major

Answer 8

origin: clavicular head and sternocostal head
insertion: intertubercular groove of humerus
innervation: medial and lateral pectoral nerves
blood supply: thoracoacromial trunk
action: flexion, adduction, and medial rotation of humerus

Question 9

Pectoralis minor

Answer 9

Origin: ribs 3-5 near costal cartilage
Insertion: coracoid process of scapula
innervation: medial pectoral nerve
blood supply: thoracoacromial trunk
action: pull scapula anterior and inferiorly

Question 10

Latissimus Dorsi

Answer 10

Origin: spinous processes T7-L5, thoracolumbar fascia, iliac crest
Insertion: intertubercular groove of humerus
innervation: thoracodorsal nerve (middle subscapular)
blood supply: thoracodorsal artery
action: extension, adduction, and medial rotation of humerus

Question 11

Biceps Brachii

Answer 11

Anterior arm
Origin: short head = coracoid process of scapula; long head = supraglenoid process of scapula
Insertion: radial tuberosity via biceps brachii tendon
innervation: musculocutaneous nerve
blood supply: brachial artery
action: flexion and supination of forearm

Question 12

Coracobrachialis

Answer 12

anterior arm
Origin: coracoid process of scapula
Insertion: medial humerus
innervation: musculocutaneous nerve
blood supply: brachial artery
action: flexion and adduction of arm

Question 13

Brachialis

Answer 13

anterior arm
Origin: anterior humerus
Insertion: coronoid process of the ulna
innervation: musculocutaneous nerve
blood supply: radial recurrent artery
action: flexion of forearm

Question 14

Teres major

Answer 14

Origin: inferior angle of scapula
Insertion: intertubercular groove of humerus
Innervation: lower subscapular nerve
blood supply: subscapular and circumflex scapular arteries
action: adduction and medial rotation of humerus

Question 15

Triceps Brachii

Answer 15

Origin:
- long head: infraglenoid tubercle
- lateral head: posterior humerus superior to the radial groove
- medial head: posterior humerus inferior to the radial groove
Insertion: olecranon via triceps brachii tendon
Innervation: radial nerve
Blood supply: deep artery of arm
Action: forearm extension
- long head: adduction and retroversion of humerus; stabilization of glenohumeral joint

Question 16

Anconeus

Answer 16

Origin: lateral epicondyle of humerus
Insertion: lateral olecranon
Innervation: radial nerve
Blood supply: deep artery of arm
Action: assists in forearm extension

Question 17

Pronator teres

Answer 17

anterior forearm
Origin: Medial epicondyle of humerus via common flexor tendon
Insertion: middle/lateral radius
Innervation: Median nerve
Blood supply: ulnar + radial artery
Action: hand pronation; forearm flexion

Question 18

Flexor carpi radialis

Answer 18

Origin: medial epicondyle of humerus via common flexor tendon
Insertion: base of 2nd metacarpal
Innervation: median nerve
Blood supply: radial artery
Action: hand flexion + abduction

Question 19

Palmaris longus

Answer 19

Origin: medial epicondyle of humerus via common flexor tendon
Insertion: Palmar aponeurosis
Innervation: median nerve
Blood supply: ulnar artery
Action: hand flexion

Question 20

Flexor carpi ulnaris

Answer 20

Origin: medial epicondyle of humerus via common flexor tendon
Insertion: pisiform, hamate, and base of 5th metacarpal
Innervation: ulnar nerve
Blood supply: ulnar artery
Action: hand flexion, adduction

Question 21

Flexor digitorum superficialis

Answer 21

Origin: median epicondyle of humerus via common flexor tendon
Insertion: 4 tendons to middle phalanges of digits 2-5
Innervation: median nerve
Blood supply: ulnar artery
Action: flexion of digits 2-5 at PIP