Flexor/Extensor Region of Arm, Cubital Fossa

Question 1

Coracobrachialis

Answer 1

O:  Tip of coracoid process of scapula
I:  Middle third of medial surface of humerus
N:  Musculocutaneous Nerve
A:  1.  Help Flex and Adduct Arm
     2.  Resists dislocation of shoulder

Question 2

Biceps Brachii

Answer 2

O: Short Head: Tip of coracoid process of scapula
Long Head: Supraglenoid Tubercle of scapula
I: 1. Tuberosity of radius
2. Fascia of forearm via bicipital aponeurosis
N: Musculocutaneous Nerve C5, C6
A: 1. Supinate forearm
2. When supine, flexes forearm
3. Short head resists dislocation of shoulder

Question 3

Brachialis

Answer 3

O: Distal half of anterior surface of humerus
I: Coronoid process and tuberosity of ulna
N: 1. Musculocutaneous Nerve
2. Radial Nerve
A: Flex forearm in all positions

Question 4

Pronator Teres

Answer 4

O: Ulnar Head: Coronoid Process
Humeral Head: Medial Epicondyle of Humerus
I: Middle of Convexity of lateral surface of radius
N: Median Nerve
A: 1. Pronate forearm
2. Flex forearm (at elbow)

Question 5

Brachioradialis

Answer 5

O: Proximal 2/3 of supracondylar ridge of humerus
I: Lateral surface of distal end of radius proximal to styloid
N: Radial Nerve C5, C6
A: Relatively weak flexor of forearm; maximal when forearm is mid- pronation position

Question 6

Extensor Carpi Radialis Longus

Answer 6

O: Lateral supracondylar ridge of Humerus
I: Dorsal aspect of base of 2nd metacarpal
N: Radial Nerve C6, C7
A: 1. Extend and abduct hand at wrist
2. Active during hand-clenching

Question 7

Supinator

Answer 7

O: 1. Lateral epicondyle of humerus
2. Radial collateral and annular ligaments
3. Supinator fossa
4. Crest of Ulna
I: Lateral, posterior, and anterior surfaces of proximal 1/3 of radius
N: Radial Nerve C6, C7
A: 1. Supinate forearm
2. Rotates radius to turn palm anteriorly and superiorly (if elbow is flexed)

Question 8

Triceps Brachii

Answer 8

O: Long Head: Infraglenoid tubercle of scapula
Lateral Head: Posterior Surface of humerus, superior to radial groove
Medial Head: Posterior surface of humerus, inferior to radial groove
I: 1. Proximal end of olecrenaon of ulna
2. Fascia of Forearm
N: Radial Nerve C6, C7, C8
A: 1. Chief extensor of forearm
2. Long head resists dislocation of humerus, especially important during abduction