Breast anatomy and physiology

Question 1

Which hormone stimulates the lactiferous duct system to grow at puberty?

Answer 1

Oestrogen

Question 2

Which hormone stimulates the mammary gland to produce milk?

Answer 2

Prolactin

Question 3

Which hormone stimulates the myoepithelisal cell lining the milk ducts to contract?

Answer 3

Oxytocin

Question 4

How many lobules does each mammary gland consist of?

Answer 4

15-20

Question 5

What ribs does the breast overlie?

Answer 5

2-6

Question 6

What is the blood supply of the medial breast?

Answer 6

Branches of the internal thoracic and anterior intercostal arteries

Question 7

What is the lymph drainage of the medial breast?

Answer 7

Drains into the internal thoracic nodes

Question 8

Where is the retromammary space?

Answer 8

Between the fascia and the breast

Question 9

How is the breast attached to the skin?

Answer 9

Suspensory ligaments

Question 10

Where does most lymph from the breast drain?

Answer 10

Up to 75% of lymph drains to the ipsilateral axillary lymph nodes and then to the supraclavicular nodes

Question 11

What are the levels of axillary lymph nodes?

Answer 11

Level I – inferior and lateral to pectoralis minor

Level II – deep to pectoralis minor

Level III – superior and medial to pectoralis minor