Upper Limb Chapter 2: Pectoral Region

Question 1

What are supraclavicular nerves?

Answer 1

(C3,4) Branches from the cervical plexus in the neck. They are divided into medial lateral, and intermediate supraclavicular nerves.

Question 2

What do the supraclavicular nerves supply?

Answer 2

They supply the skin covering the area between the clavicle and the 2nd rib including the skin covering upper 1/2 of the deltoid muscle.

Question 3

The lateral supraclavicular nerve supplying?

Answer 3

(C4) supplies the skin and the upper part of the shoulder region.

Question 4

Anterior and lateral cutaneous branches of the intercoastal nerves supply?

Answer 4

(T2- T6) supply the skin covering the area below the 2nd rib.

Question 5

Pectoral region include:

Answer 5

Upper part of the front of the chest wall down to the 6th rib:
Skin, superficial fascia (contains mammary glands) , deep (pectoral) fascia, and muscles.

Question 6

What does the pectoral fascia cover?

Answer 6

It is the deep fascia of the pectoral region that covers the pectoralis major muscle beneath the breast.

Question 7

What are the extensions of the pectoral fascia?

Answer 7

1. Axillary fascia which forms the floor of the Axilla.
2. Clavipectoral Fascia.

Question 8

Where is the site of the clavipectoral fascia?

Answer 8

Strong fibrous sheet of deep fascia that covers the interval between the subclavius muscle above to the pectoralis minor below. It covers the Axillary vessels and veins.

Question 9

Clavi-pectoral fascia attachments

Answer 9

Above, it splits to enclose the subclavius muscle and becomes attached to the margins of the groove of the subclavius on the lower surface of the clavicle.
Medially, thickened and attaches to the first and second costal cartilages.
Laterally, extends to the coracoid process where is blends with the coracoclavicular ligament.
Below, splits to enclose pectoral is minor.

Question 10

When the fascia continuous downwards, what is it called?

Answer 10

Suspensory ligament of the Axilla to join the Axillary fascia in the floor of Axilla.

Question 11

What is the fascia from the clavicle to the floor of Axilla called?

Answer 11

Axillary septum.

Question 12

What are the structures piercing in through the clavi-pectoral region?

Answer 12

1. Cephalic vein.
2. Lateral pectoral nerve
3. Acromio-thoracic artery.
4. Lymph vessels from the infra-clavicular lymph nodes (outside the Axilla) draining into the apical group of Axillary lymph nodes.

Question 13

What is a Pectoralis Major Muscle?

Answer 13

Superficial muscle of the pectoral region, which extends laterally to form the anterior wall of the Axilla.

Question 14

What is the pectoralis major Origin?

Answer 14

It arises by 2 heads:
Clavicular head: anterior surface of the medial 1/2 of the clavicle.
Sternocoastal head: larger.
- Anterior surface of the sternum.
- Front of the upper 6 coastal cartilages.
- Aponeurosis of external abdominal oblique muscle.

Question 15

Pectoralis major insertion

Answer 15

Bilaminar tendon into the lateral lip of the intertubercular biciptal groove.

Question 16

Pectorals major nerve supply

Answer 16

Medial and lateral pectoral nerves.

Question 17

Pectoral major actions

Answer 17

As a whole: the muscle adducts and medially rotates the arm.
Clavicular head: flexes the arm.
Sternocoastal head: extends. Helps in swimming, rowing, and climbing.

Question 18

Pectoralis minor

Answer 18

Deep to the middle part of the Pectoralis major.

Question 19

Pectoralis minor origin

Answer 19

Outer surface of the 3rd, 4th, and 5th ribs near their costal cartilages.

Question 20

Pectoralis minor insertion

Answer 20

Medial border and upper surface of the coracoid process.

Question 21

Pectoralis minor nerve supply

Answer 21

Medial pectoral nerve

Question 22

Pectoralis minor action

Answer 22

Protraction of the shoulder girdle, depression of the shoulder girdle, and with fixed scapula, it can raise the ribs in forced inspiration.

Question 23

Subclavius

Answer 23

Slender muscle present just below the clavicle.

Question 24

Subclavius origin

Answer 24

Upper surface of the 1st coastal-chondral junction.

Question 25

Subclavius insertion

Answer 25

Into a groove on the lower surface of the middle third of the clavicle.

Question 26

Subclavius nerve supply

Answer 26

Nerve to subclavius (C5).

Question 27

Subclavius action

Answer 27

Steadies the clavicle thus preventing excessive movement of the shoulder girdle.