Arm muscles

Question 1

CORACOBRACHIALIS

• Origin
• Insertion

Answer 1

Origin:

• Coracoid process

Insertion:

• Medial humerus

Question 2

Corachobrachialis

• ​Actions
• Innervation

Answer 2

Action

• Arm flexion/adduction

Innervation:

• Musculocut. n (C5-7)

Question 3

Biceps Brachii

• Origin
• Insertion

Answer 3

Origin:

• Short head: coracoid process
• Long head: supraglenoid tubercle

Insertion:

• Radial tuberosity (stronger one)
• Bicipital aponeurosis (weaker one)

Question 4

Biceps Brachii

• ​Actions
• Innervation

Answer 4

Action:

• Arm flexion
• Forearm supination

Innervation:

• Musculocut. n.

Question 5

Brachialis

• Origin
• Insertion

Answer 5

Origin:

• Distal anterior humerus

Insertion:

• Ulnar tuberosity
• Ulnar coronoid process

Question 6

Brachialis

• ​Actions
• Innervation

Answer 6

Action

• Flexion of elbow joint

Innervation

• Musculocut. n.

Question 7

Triceps Brachii

• Origin
• Insertion

Answer 7

Origin:

• Long head: infraglenoid tubercle
• Medial head: posterior humerus and medial IM septum; distal to spiral groove
• Lateral head: beneath greater tubercle; lateral and proximal to spiral groove

Insertion:

• Flat common end tendon at olecranon process (all three heads)

Question 8

Triceps Brachii

• ​Actions
• Innervation

Answer 8

Action

• Extension of elbow joint
• Long head: At shoulder, involved in extension/adduction of arm

Innervation:

• Radial n. (C5-C8)

Question 9

Aconeus

• Origin
• Insertion

Answer 9

Origin:

• Pos. lateral epicondyle
• Lateral collateral lig.

Insertion:

• Proximal ¼ of pos. ulnar
• (near tri. Medial head)

Question 10

Aconeus

• ​Actions
• Innervation

Answer 10

​Actions:

• Assist triceps in extension
• Abduct/rotate ulna during forearm pronation

Innervation:

• Radial n.