Muscles of the Posterior Arm

Question 1

Triceps Brachii (long head)

Answer 1

origin: infraglenoid tubercle
insertion: olecranon of the ulna
innervation: radial N. (C5-T1)
action: extension at the elbow joint, extension at the shoulder

Question 2

Triceps Brachii (lateral head)

Answer 2

origin: posterior humerus lateral and superior to the radial groove
insertion: olecranon of the ulna
innervation: radial N. (C5-T1)
action: extension at the elbow joint

Question 3

Triceps Brachii (medial head)

Answer 3

origin: posterior humerus medial and inferior to the radial groove
insertion: olecranon of the ulna
innervation: radial N. (C5-T1)
action: extension at the elbow joint