12. Muscles of Arm: Anterior View

Question 1

Identify 1 - 2

Answer 1

1. Biceps brachii muscle
2. Deltoid muscle (reflected)

Question 2

Identify 3- 5

Answer 2

3. Subscapularis muscle
4. Teres major muscle
5. Latissimus dorsi muscle

Question 3

Identify 6 - 7

Answer 3

6. Bicipital aponeurosis
7. Biceps brachii tendon

Question 4

Identify 1. O & I

Answer 4

1. Biceps brachii muscle
   * *Origin (proximal):** The short head of the biceps brachii muscle arises from the apex of the coracoid process of the scapula. The long head of the biceps brachii muscle arises from the supraglenoid tubercle of the scapula.

Insertion (distal): Both muscle bellies form a tendon that is inserted into the radial tuberosity.

Question 5

1. Biceps brachii muscle
   * *Origin (proximal):** The short head of the biceps brachii muscle arises from the apex of (1)____ The long head of the biceps brachii muscle arises from (2)____

Insertion (distal): Both muscle bellies form a tendon that is inserted into the radial tuberosity.

Answer 5

1. the coracoid process of the scapula.
2. The supraglenoid tubercle of the scapula.

Question 6

1. Biceps brachii muscle

Insertion (distal):

Both muscle bellies of the biceps brachii muscle join to form a flattened tendon that is inserted into (1)_____.

Opposite the elbow, the tendon gives off THE (2)____ THAT descends medially to fuse with the (3)___

Answer 6

1. the radial tuberosity
2. bicipital aponeurosis
3. deep fascia of the forearm.

Question 7

Identify 1. Action

Answer 7

1. Biceps brachii muscle

Action:

• With the forearm partially flexed, the biceps brachii is a powerful supinator of the forearm.
• flexor of the supinated forearm.
• Weak flexor of the arm at the shoulder.

Question 8

Identify 1. Innervation

Answer 8

1. Biceps brachii muscle

Innervation: Musculocutaneous nerve (C5 and C6).

Question 9

the biceps is a (1)___ muscle that has 2 heads. Its insertion by the (2)____ allows it to flex the (3)___.

Answer 9

1. fusiform
2. bicipital aponeurosis
3. elbow

Question 10

Which artery supplies blood to Biceps brachii muscle?

Answer 10

1. the brachial artery

Question 11

Identify 1 → 5

Answer 11

1. Coracobrachialis muscle
2. Subscapularis muscle
3. Musculocutaneous nerve
4. Teres major muscle
5. Latissimus dorsi muscle

Question 12

Identify 1. O & I

Answer 12

1. Coracobrachialis muscle

Origin - Coracoid process of the scapula

Insertion - Anteromedial surface of the humerual shaft

Question 13

Identify 1. Action

Answer 13

1. Coracobrachialis muscle

Action: Flexes and adducts the arm at the shoulder.

Question 14

Identify 1. Innervation

Answer 14

1. Coracobrachialis muscle

Innervation: Musculocutaneous nerve (C6 and C7).

Question 15

The coracobrachialis is the ___ (biggest/smallest) of the 3 anterior compartment muscles of the arm.

Answer 15

1. smallest

Question 16

___ supplies the coracobrachialis with blood.

Answer 16

The brachial artery

Question 17

As the musculocutaneous nerve leaves the (1)___, it usually dives into the proximal portion of (2)___.

Answer 17

1. brachial plexus
2. the coracobrachialis muscle

(S_ince the musculocutaneous nerve runs through the coracobrachialis muscle, it is vulnerable to_ nerve compression within the muscle, and this can lead to weakness of elbow flexion (loss of some brachialis and biceps function) and hypesthesia of the lateral forearm.)

Question 18

Identify

Answer 18

1. Brachialis muscle
2. Coracoid process
3. Acromion
4. Biceps brachii tendons (cut) (Long and Short heads)
5. Lateral antebrachial cutaneous nerve

Question 19

Identify 1. O & I

Answer 19

1. Brachialis muscle

Origin (proximal): Brachialis muscle arises from the distal half of the anterior humerus.

Insertion (distal): Inserts into the tuberosity and the anterior surface of the coronoid process of the ulna.

Question 20

Identify 1. Action

Answer 20

1. Brachialis muscle

Action: The brachialis is a powerful flexor of the forearm at the elbow.

Question 21

Identify 1. Innervation

Answer 21

1. Brachialis muscle

• Musculocutaneous nerve (C5 and C6).
• Also, the radial nerve sends a minor branch to the brachialis (C7).

(l: Damage to the musculocutaneous nerve proximal to the brachialis (compression injury as it passes through the coracobrachialis muscle) can lead to weakness in the brachialis and biceps brachii muscles, thus affecting elbow flexion.)

Question 22

Because the brachialis is covered superficially by the (1)____, it is often not appreciated as the most important and powerful flexor of the forearm at the elbow.

Although the muscle can participate in quick flexion, its isometric contraction maintains the (2)___ position, especially when a weight is applied to the forearm.

Answer 22

1. biceps
2. flexed

Question 23

__ supplies the brachialis with blood.

Answer 23

1. Brachialis muscle

Muscular branches of brachial artery