Muscles of Arm

Question 1

Biceps Brachii

Answer 1

supinates foremarm and, when it is supinated, flexes elbow joint; flexes shoulder joint; short head resists dislocation of shoulder
nerve supply- musculocutaneous nerve
short head: tip of coranoid process of scapula
long head: supraglenoid tubercle of scapula
-> tuberosity of radius and fascia of forearm via bicipital aponeurosis

Question 2

Brachialis

Answer 2

flexes elbow joint in all positions
nerve supply - musculocutaneous nerve
distal half of anterior surface of humerus -> coronoid process and tuberosity of ulna

Question 3

Coracobrachialis

Answer 3

helps flex and adduct shoulder joint; resists dislocation of shoulder
nerve supply - musculocutaneous nerve
tip of coracoid process of scapula -> middle third of medial surface of humerus

Question 4

Triceps brachii

Answer 4

chief extensor of elbow joint; long head extends shoulder joint and resists dislocation of humerus
nerve supply - radial nerve
long head, lateral head and medial head -> proximal end of olecranon of ulna and fascia of forearm

Question 5

Aconeus

Answer 5

assists triceps in extending elbow joint; stabilizes elbow joint; abducts ulna during pronation
nerve supply - radial nerve
lateral epicondyle of the humerus -> lateral surface of olecranon and superior part of posterior surface of ulna