Muscles of the arm

Question 1

What are the muscles of the anterior compartment of the arm (BBC)?

Answer 1

Biceps brachii
Brachialis
Coracobrachialis

Question 2

Biceps Brachii

Answer 2

O: Supraglenoid tubercle of the scapula (long head); coracoid process of the scapula (short head)

I: Radial tuberosity and into deep fascia of the forearm (via bicipital aponeurosis)

I: Musculocutaneous nerve

A: Supination of the forearm (at radioulnar joints) and flexion of the arm (at elbow and shoulder joints)

Question 3

What is the bicipital aponeurosis?

Answer 3

Thick fascial band that originates close to the musculotendinous junction of the biceps
-forms the roof of the cubital fossa

Question 4

Coracobrachialis

Answer 4

O: Coracoid process of the scapula

I: Medial side of the humeral shaft

I: Musculocutaneous nerve

A: Flexion of the arm and weak abductor

Question 5

Brachialis

Answer 5

O: Anterior surface of the distal half of the humeral shaft

I: Coronoid process of the ulna and the ulnar tuberosity

I: Musculocutaneous nerve

A: Flexion of the forearm (at the elbow)

(forms the floor of the cubital fossa)

Question 6

What forms the posterior compartment of the arm?

Answer 6

Triceps brachii

Question 7

Triceps Brachii

Answer 7

O: Infraglenoid tubercle of the scapula (long head); Humerus shaft SUPERIOR to radial groove (lateral head); Humerus shaft INFERIOR to radial groove (medial head)

I: Olecranon of the ulna (heads converge to one tendon)

I: Radial nerve

A: Extension of the forearm (at the elbow)