Arm and elbow OIA

Question 1

Coracobrachialis

Answer 1

Origin: Coracoid process

Insertion: Mid-shaft of humerus on antero-medial
surface

Innervation: Musculocutaneous nerve (C5 - C7)

Action: Adduction and flexion of the arm

Question 2

Brachialis

Answer 2

Origin: Anterior distal half of the humerus

Insertion: Tuberosity of ulna

Innervation: Musculocutaneous nerve (C5 and C6)

Action: Flexion of forearm

Question 3

Biceps brachii

Answer 3

Origin: Long head – Supraglenoid tubercle of scapula;
short-head – coracoid process

Insertion: Radial tuberosity

Innervation: Musculocutaneous nerve (C5 & C6)

Action: Flexion and supination of forearm

Question 4

Triceps brachii

Answer 4

Origin: Long head: Infraglenoid tubercle
Lateral head: Posterior surface of humerus
Medial head: Posterior surface of humerus

Insertion: Olecranon

Innervation: Radial nerve (C6 - C8)

Action: Extension of forearm
Long head: can also extend & adduct
the arm

Question 5

Flexor carpi ulnaris

Answer 5

Origin: Medial epicondyle & olecranon

Insertion: Pisiform, hamate & 5th metacarpal

Innervation: Ulnar nerve (C7, C8)

Action: Flexes & adducts wrist (ulnar deviation)

Question 6

Palmaris longus

Answer 6

Origin: Medial epicondyle

Insertion: Palmar aponeurosis and flexor retinaculum

Innervation: Median nerve (C7, C8)

Action: Flexes wrist & tenses palmar aponeurosis

Question 7

Flexor carpi radialis

Answer 7

Origin: Medial epicondyle

Insertion: Base of metacarpals II & III

Innervation: Median nerve (C6, C7)

Action: Flexes and abducts the wrist

Question 8

Pronator teres

Answer 8

Origin: Medial epicondyle & coronoid process

Insertion: Lateral surface mid-shaft of radius

Innervation: Median nerve (C6, C7)

Action: Pronation

Question 9

Flexor digitorum superficialis

Answer 9

Origin: Medial epicondyle & margin coronoid process; oblique line of radius

Insertion: 4 tendons – middle phalanges of the index, middle, ring and little fingers

Innervation: Median nerve (C7, T1)

Action: Flexes wrist, flexes middle and proximal phalanges of digits 2-5

Question 10

Flexor digitorum profundus

Answer 10

Origin: Anterior & medial surface of ulna & interosseous membrane

Insertion: Four tendons – distal phalanges of the index, middle, ring & little fingers

Innervation: Interosseous branch of the medial and ulnar nerves (C8, T1)

Action: Flexes distal interphalangeal joints

Question 11

Flexor pollicis longus

Answer 11

Origin: Anterior surface of radius & interosseous membrane

Insertion: Base of distal phalanx of thumb

Innervation: Medial nerve (C7, C8)

Action: Flexes distal phalanx of the thumb

Question 12

Pronator quadratus

Answer 12

Origin: Distal fourth of anterior surface of the ulna

Insertion: Distal fourth of anterior surface of the radius

Innervation: Median nerve (C7, C8)

Action: Pronation

Question 13

Brachioradialis

Answer 13

Origin: Lateral supra-epicondylar ridge

Insertion: lateral side of the base of the styloid process of the radius

Innervation: Radial nerve (C5, C6)

Action: Flexes the forearm at the elbow

Question 14

Extensor carpi radialis longus

Answer 14

Origin: Lateral supraepicondylar ridge

Insertion: Base of metacarpaI II

Innervation: Radial nerve (C6, C7)

Action: Extends & abducts the wrist

Question 15

Extensor carpi radialis brevis

Answer 15

Origin: Lateral epicondyle

Insertion: Base of metacarpal III

Innervation: Deep branch of radial nerve ( C7, C8)

Action: Extends & abducts the wrist

Question 16

Extensor digitorum

Answer 16

Origin: Lateral epicondyle

Insertion: 4 tendons (extensor hoods) – base of middle & phalanges of index, middle, ring & little fingers

Innervation: Posterior interosseous (C7, C8)

Action: Extends the index, middle, ring & little fingers

Question 17

Extensor digiti minimi

Answer 17

Origin: Lateral epicondyle

Insertion: Dorsal digital expansion on the 1st phalax of the little finger

Innervation: Posterior interosseous (C7, C8)

Action: Extends the little finger

Question 18

Extensor carpi ulnaris

Answer 18

Origin: Lateral epicondyle & posterior border of ulna

Insertion: Tubercle on the base of the medial side of metacarpal V

Innervation: Posterior interosseous (C7, C8)

Action: Extends & adducts the wrist

Question 19

Anconeus

Answer 19

Origin: Lateral epicondyle

Insertion: Olecranon process & proximal posterior surface of ulna

Innervation: Radial nerve (C7, C8)

Action: Abduction of the ulna in pronation - The anconeus abducts the ulna during pronation to maintain the center of the palm over the same point when the hand is flipped. It is also considered to be an accessory
extensor of the elbow joint

Question 20

Supinator

Answer 20

Origin: Superior – Lateral epicondyle; Deep – Superior crest of ulna

Insertion: Lateral surface of radius superior to the anterior oblique line

Innervation: Posterior interosseous (C6, C7)

Action: Supination

Question 21

Abductor pollicus longus

Answer 21

Origin: Posterior surface of ulna & radius, and interosseous membrane

Insertion: Lateral side of base of metacarpal I

Innervation: Posterior interosseous (C7, C8)

Action: Abducts carpometacarpal joint of thumb

Question 22

Extensor pollicis brevis

Answer 22

Origin: Posterior surface of radius & interosseous membrane

Insertion: Dorsal surface of base of proximal phalanx of the thumb

Innervation: Posterior interosseous (C7, C8)

Action: Extension of thumb, adduction of the wrist

Question 23

Extensor pollicis longus

Answer 23

Origin: Posterior surface of ulna & interosseous membrane

Insertion: Dorsal surface of base of the distal phalanx of thumb

Innervation: Posterior interosseous (C7, C8)

Action: Extension of thumb, abduction of wrist

Question 24

Extensor indicis

Answer 24

Origin: Posterior surface of ulna & interosseous membrane

Insertion: Extensor hood of index finger

Innervation: Posterior interosseous (C7, C8)

Action: Extension of the wrist and joints of the second digit