Upper Limb Chapter 3: Muscles Of The Back

Question 1

What are muscles of the back?

Answer 1

Muscles of the upper limb situated in the back and connect the upper limb to the vertebral column.

Question 2

What are the muscles of the back supplied with?

Answer 2

Anterior primary rami of the spinal nerves.

Question 3

What are the two layers of the muscles of the back?

Answer 3

Superficial layer:
1. Trapezius
2. Lattismus Dorsi
Deep layer:
1. Levantine scapulae
2. Rhomboideus major
3. Rhomboideus minor

Question 4

Trapezius

Answer 4

A large triangular muscle covering the upper half of the back. The two muscles of both sides form together the outline of a trapezium.

Question 5

Trapezius origins

Answer 5

1. Back of the skull
2. Back of the neck
3. Back of the thorax

Question 6

Back of the skull trapezius

Answer 6

External occipital protuberance and the medial third of the nuchal line.

Question 7

Back of the neck

Answer 7

Ligmentum nuchae and the spine of the 7th cervical vertebra.

Question 8

Back of the thorax

Answer 8

Spines of all thoracic vertebrae and their supraspinous ligaments.

Question 9

Lattismus dorsi

Answer 9

A triangular flat muscle covering the lower half of the back down to the iliac crest. It has a wide origin and a narrow tendon of insertion.

Question 10

Lattismus dorsi origin

Answer 10

It arises by:
1. Posterior third of the outer lip of the Iliad crest.
2. Spines of the lower 6 thoracic vertebrae, undercover of the trapezius.
3. Thoracic lumbar fascia.
4. Outer surface of the lower 4 ribs.
5. Few fibers from the dorsal aspect of the inferior angle of the scapula.

Question 11

Lattismus dorsi insertion.

Answer 11

Floor of the bicipital groove.

Question 12

Lattismus dorsi nerve supply

Answer 12

Thoraco-dorsal or Lattismus dorsi nerve

Question 13

Action of Lattismus dorsi

Answer 13

1. Extension, medial rotation, and adduction of the arm. (Rowing and swimming).
2. Acting with Sternocoastal part of the Pectoralis major, it pulls the trunk upwards as in climbing (acting from insertion).
3. Through its attachment to the ribs, it assists in violent expiration as in coughing.

Question 14

Triple relation with teres major

Answer 14

The upper border of the muscle crosses the inferior angle of the scapula and has triple relation to the teres major as follows:
First it lies behind the teres major, then it curves below the teres major.
At it’s insertion, it comes in front of the teres major.
- the Lattismus dorsi at its insertion usually fuses with the teres major to form the posterior Axillary fold.

Question 15

Posterior Axillary fold

Answer 15

Lattismus dorsi at its insertion usually fuses with the teres major to form the posterior Axillary fold.

Question 16

Triangle of auscultation

Answer 16

Located medially to the lower part of the scapula.

Question 17

Triangle of auscultation boundaries

Answer 17

Above: lateral border of trapezius.
Below: upper border of Lattismus dorsi.
Laterally: lower part of the medial border of the scapula.

Question 18

Triangle of auscultation floor

Answer 18

Rhomboideus major.
Sixth and seventh ribs and the space in between.

Question 19

Lumbar triangle

Answer 19

Situated just above the iliac crest and might be the site of the hernia (lumber hernia).

Question 20

Lumber triangle boundries

Answer 20

Below: iliac crest
Medially: lateral border of external abdominal oblique muscle.
Laterally: vertical posterior border of external oblique abdominal muscle.

Question 21

Lumber triangle floor.

Answer 21

Formed of internal abdominal oblique and transversus absominis muscles.

Question 22

Lavatory scapulae origin

Answer 22

It arises by 4 slips from the transverse processes of the upper 4 cervical vertebrae.

Question 23

Rhomboideus minor origin

Answer 23

From the lower part of the ligmentum nuchae, the spines of the 7th cervical to the 1st thoracic vertebrae.

Question 24

Rhomboideus major origin

Answer 24

From the spines 2nd, 3th, 4th, and 5th thoracic vertebra and their supraspinous ligaments.

Question 25

Levator scapulae insertion

Answer 25

Dorsal surface of the medial border of the scapula above the root of the spine.

Question 26

Rhomboideus minor insertion

Answer 26

Dorsal surface of the medial border of the scapula opposite to the root of the spine.

Question 27

Rhomboideus major insertion

Answer 27

Dorsal surface of the medial border of the scapula from the root of the spine to the inferior angle.

Question 28

Levator scapulae nerve supply

Answer 28

Nerve to Rhomboids (dorsal scapular nerve C5)

Question 29

Rhomboideus minor nerve supply

Answer 29

Nerve to Rhomboid (dorsal scapular nerve C5)

Question 30

Rhomboideus major nerve supply

Answer 30

Nerve to Rhomboid (dorsal scapular nerve C5)

Question 31

Levator scapulae action

Answer 31

• Elevates shoulder girdle (with trapezius).
• Rotates the scapula so that the gel oil cavity looks downwards.
• Retracts the scapula.

Question 32

Rhomboideus minor action

Answer 32

• Rotates the scapula so that the glenoid cavity look downwards (with Levator scapulae).
• Retracts the scapula ( with middle fibers of trapezius).

Question 33

Rhomboideus major actions

Answer 33

• Rotates the scapula so that the glenoid cavity look downwards (with Levator scapulae).
• Retracts the scapula ( with middle fibers of trapezius).