Muscles Of The Upper Arm

Question 0

Innervation of biceps brachii

Answer 0

Musculocutaneous nerve

Question 1

Origin and insertion of biceps brachii (short and long head)

Answer 1

O: short head- coracoid process
Long head- supra- glenoid tubercle

I- tuberosity of radius and fascia of forearm

Question 2

Action of biceps brachii

Answer 2

Supinate a forearm and when it’s supine, it flexes forearm; short head resists dislocation if shoulder

Question 3

Origin and insertion of coracobrachialis

Answer 3

O- tip of coracoid process

I- median surface of humerus

Question 4

Innervation of coracobrachialis

Answer 4

Musculocutaneous nerve

Question 5

Main action of coracobrachialis

Answer 5

Helps flex and adducts the arm

Resists dislocation of shoulder

Question 6

Origin and insertion if brachialis

Answer 6

O- distal half of anterior humerus

I- coranoid process and tuberosity of ulna

Question 7

Innervation of brachialis

Answer 7

Musculocutaneous nerve

Question 8

Action if brachialis

Answer 8

Flexes forearm in all positions

Question 9

Origin and insertion of triceps brachii

Long head, lateral head and medial head

Answer 9

O- long head- infraglenoid tubercle
Medial head- posterior surface of humerus- inferior to radial groove
Lateral head- posterior surface of humerus - superior to radial groove

I- proximal end if olecranon process of ulna

Question 10

Innervation of triceps brachii

Answer 10

Radial nerve

Question 11

Action of triceps brachii

Answer 11

Chief extensor muscles
Long head resists dislocation of humerus
Helps in adduction (long head)

Question 12

Origin and insertion of anconeus

Answer 12

O- lateral epicondyle of humerus

I- lateral surface of olecranon and posterior ulna

Question 13

Innervation of anconeus

Answer 13

Radial nerve

Question 14

Action of anconeus

Answer 14

Assists triceps in extending forearm; stabilises elbow joint; may abduct ulna during pronation