Arm and Elbow muscles

Question 1

coracobrachialis

Answer 1

anterior compartment

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

anterior compartment

origin:
- anterior distal half of the humerus

insertion:
- tuberosity of ulna

innervation:
- musculocutaneous nerve (C5-C7)

action:
- flexion of the arm

Question 3

biceps brachii

Answer 3

anterior compartment

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

posterior compartment

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