2 Extrinsic Muscles of Back

Question 1

Extrinsic Muscles of Back

→ Identify 1 - 2

Answer 1

1. Rhomboid major muscle
2. Rhomboid minor muscle

Question 2

Extrinsic Muscles of Back

→ Identify 1 - 2

→ O & I?

Answer 2

1. Rhomboid major muscle
2. Rhomboid minor muscle

Origin:

• The rhomboid minor muscle arises from the ligamentum nuchae and the spinous processes of the C7 and T1 vertebrae.
• The rhomboid major muscle arises from the supraspinous ligaments and the spinous processes of the T2-T5 vertebrae.

Insertion: attach to the medial border of the scapula from about the level of the spine to the inferior angle.

Question 3

Extrinsic Muscles of Back

→ Identify 1 - 2

→ ACTION?

Answer 3

1. Rhomboid major muscle
2. Rhomboid minor muscle

Action:

• retract the scapula and rotate it to depress the glenoid cavity.
• fix the scapula to the thoracic wall.
• assist in forcibly lowering the raised upper limb.

Question 4

Extrinsic Muscles of Back

→ Identify 1 - 2. Innervation

Answer 4

1. Rhomboid major muscle
2. Rhomboid minor muscle

Innervation: Dorsal scapular nerve (C4 and C5).

Question 5

Extrinsic Muscles of Back

The rhomboid minor and rhomboid major muscles are superficial or deep back muscles.

Answer 5

The rhomboid minor and rhomboid major muscles are superficial back muscles.

Question 6

Extrinsic Muscles of Back

Most superficial back muscles have attachments to (1)____ and are involved with movements of (2)____

Answer 6

1. the scapula
2. the upper limb.

Question 7

Extrinsic Muscles of Back

→ Identify 3 - 4

Answer 7

3. Accessory nerve (CN XI) (innervates trapezius muscle)
4. Trapezius muscle (reflected)

Question 8

Extrinsic Muscles of Back

→ Identify 6

Answer 8

6 Latissimus dorsi muscle