2 - Aldridge - Pectoral Region / Axilla

Question 1

Mammary Gland

Answer 1

Modified sweat gland that secretes Milk

Ducts/secretory units well developed in post-puberty females; males contain structures but not well developed

Question 2

Retromammary Space

Answer 2

Potential space between gland and deep fascia of pectoralis major; allows for some movement of breast

Question 3

Suspensory Ligaments (of Cooper)

Answer 3

Fibrous bands that attach the breast to the overlying skin

Act as walls which divide breast into fat-filled lobes (contain milk glands)

Carcinoma creates tension in these, causing pitting of the skin

Question 4

Axillary Tail (of Spence)

Answer 4

Small part of the fland that extends superio-laterally into the armpit (axilla)

Question 5

Lobes (of Breast)

Answer 5

Divide breast into 15-20 compartments, each separated by suspensory ligaments

Contains fat, glandular tissue, and lactiferous ducts

Question 6

Nipples

Answer 6

Surrounded by areola, lactiferous duct from each lobe empties at the nipple

Question 7

Arterial supply for breast?

Answer 7

Perforating Branches and Anterior Intercostal Branches of Internal Thoracic Artery

Lateral Thoracic and Thoracoacromial branches of Axillary Artery

Question 8

Lymphatic Drainage (of breast)

Answer 8

Lateral quadrants of breast:

Drain into anterior (or pectoral) group

75% to anterior group

- - - -

Medial quadrants of breast:

Drain into parasternal nodes located along internal thoracis vessels of the chest wall or drain to the opposite breast

25% to parasternal nodes

- - -

Lower quadrant of breast:

Can drain inferiorly into abdominal nodes

Question 9

Serratus Anterior Innervation

Clinical presentation of disruption?

Answer 9

Long Thoracic Nerve (C5, C6, C7)

S.A.L.T.

Serratus Anterior Long Thoracic

- - -

Winged scapula (pushing)

Question 10

Fascia of Pectoral Region

Answer 10

Invests the four pectoral muscles

1. Pectoral Fascia - covers pectoralis major
2. Clavipectoral Fascia - encloses pectoral minor and subclavius and attaches to clavicle, protects underlying neurovascular structures that supply upper limb

Question 11

What structures pierce the clavipectoral fascia?

Answer 11

1. Cephalic Vein
2. Thoracoacromial Artery
3. Lateral Pectoral Nerve
4. Medial Pectoral Nerve (on its own)

Question 12

Clavipectoral/Deltopectoral Triangle

Borders?

Contents?

Answer 12

Borders:

a. Superior - Clavicle
b. Lateral - Deltoid
c. Medial - Pectoralis Major
- - -

Contents:

a. Cephalic Vein (superficial)
b. Tip of Coracoid Process (deep, can palpate)

Question 13

Axilla

Answer 13

Pyramidal shaped area between arm and upper thorax

Passageway for the neurovascular supply to the upper limb

Question 14

Borders of Axilla:

Anterior Wall

Posterior Wall

Medial Wall

Lateral Wall

Floor

Answer 14

Anterior Wall - Pectoralis Major/Minor

Posterior Wall - Scapula, Subcapularis, Latissimus Dorsi, Teres Major

Medial Wall - Upper 4 ribs, intercostal muscles between ribs, serratus anterior

Lateral Wall - Intertubercular Groove of Humerus

Floor - Fascia and dome of skin, supported by suspensory ligament of axilla from clavipectoral fascia

Question 15

Only major structure that passes directly through medial wall, and into axilla?

Answer 15

Intercostobrachial nerve

= lateral cutaneous branch of the second intercostal nerve

Part of T2 dermatome

Question 16

Six Parts of Axillary Artery

Answer 16

S T L S A P

Part 1:

(S) - Superior Thoracic Artery

Part 2:

(T) - Thoracoacromial Artery

(L) - Lateral Thoracic Artery

Part 3:

(S) - Subscapular Artery

(A) - Anterior Circumflex Humeral Artery

(P) - Posterior Circumflex Artery

Question 17

What is the origin of the Axillary artery? What vessel does it originate from?

When does it become the brachial artery?

Answer 17

Originates from the subclavian artery in the neck

Becomes the axillary artery at the lateral margin of the 1st rib and passes through the axilla

Becomes brachial artery at the inferior margin of the teres major muscle

Question 18

Axillary Vein

Answer 18

Runs medial to the Axillary Artery

Question 19

Posterior Circumflex Artery

Answer 19

Runs posteriorly with the axillary nerve through the quadrangular space, winds posteriorly around surgical nexk of humerus

Question 20

Axillary Lymph Nodes

Answer 20

Receive lymph from the upper limb and breast, drain into subclavian lymph trunks which drain into:

Right - Right Lymphatic Duct

Left - Thoracic Duct