Breast

Question 1

Define the borders of the breast

Answer 1

Lies in the superficial fascia of the anterior chest wall
Extends transversely from the lateral border of the sternum to the midaxillary line
Vetically from the 2nd intercostal to the 6th

Two thirds of the bed of the rbeast are formed by the pec fascia overlying the pec major the other third by the fascia covering serratus anterior

Between the breast and the pectoral fascia is a loose connective tissue plane or potential space the retromammary space (bursa).

Axillary tail. A small part of the mammary gland may extend alon the inferolateral border of the pec major towards the axillary fossa forming an axillary tail. May penetrate the deep fascia to lie adjacent to axillary lymph nodes.

Connected the dermis by suspensory ligaments (of cooper)

Question 2

Describe the structure of the breast

Answer 2

The lactiferous ducts give rise to buds that form 15-20 lobules of glandular tissue which constitute the parenchyma of the mammary gland
Each lobule is drained by a lactiferous duct usually opening independently on the nipple.
Deep to the aeorla each duct has a dilated portion(lacterifous sinus which a small droplet of milk accumulates.

Numerous sebacous glands which secrete protective oily substance for the beast feeding mother

Modified sweat glands and do not have a special capsule or sheath

Question 3

Describe the vasculature of the breast

Answer 3

Derives from

• Medial mammary branches of perforating branches and anterior interostal branches of the internal thoracic artery
• Lateral and thoracoacromial arteries branches of the axillary artery
• posterior intercostal arteries branches of the thoracic aorta `

Question 4

Describe the lymphatic drainage of the breast

Answer 4

Lymph passes from the nipple areola and lobules of the gland to the subareolar lymphatic plexus

From this plexus >75% of lymph especially from the lateral breast quadrants drains to the axillary lymph nodes. Initally to the pectoral and anterior lymph nodes. Some lymph may drain to other axillary nodes or even to interpectoral, deltopectoral or supracalvicular nodes.

The remaining lymph particularly from the medial breast quadrants drain to the parasternal lymph nodes or to the opposite breast.

Inferior quadrants may pass deeply to abdominal lymph nodes

Lymph from the skin of the beast except the nipple and areola drains into the ipsilateral axillary, inferior deep cervical and infraclavicular lymph nodes

Lymph from the axillary nodes then drains into the clavicular lymph nodes and form them into the subclavian lymphatic trunk