2.4 Cont - The Breast

Question 1

How many lobes does the breast have?

Answer 1

15-25

Consists of many alveoli drained by a single lactiferous duct; these ducts converge at the nipple like spokes of a wheel

Question 2

The breast extends vertically from where to where?

Answer 2

2nd to 6th rib

Question 3

The breast extends horizontally from where to where?

Answer 3

Lateral border of the sternum to the mid-axillary line

Question 4

The deep surface of the breast is related to which muscles?

Answer 4

Pectoralis major (2/3 of breast)
Serratus anterior (1/3 of breast)
(also external oblique and rectus abdominis)

Question 5

Branches of which 2 arteries supply the breasts?

Answer 5

Subclavian

Axillary

Question 6

What branches of the subclavian supply the breast?

Answer 6

Medial mammary branches of perforating branches and anterior intercostal branches of the internal thoracic

Question 7

What branches of the axillary supply the breast?

Answer 7

Mammary branches of internal throacic and thoraco-acromial arteries

Question 8

What are the 3 main groups of lymph nodes draining breast tissue?

Answer 8

Axillary (skin/lateral quadrants)
Parasternal (medial quadrants)
Supraclavicular

Question 9

Which group of lymph nodes first receives lymph from the lateral part (quadrant) of the breast tissue?

Answer 9

Pectoral nodes

Question 10

How is it possible for breast cancer to spread from one breast to the other?

Answer 10

Lymph from medial side of one breast can drain to the opposite side

Question 11

What is the difference between an active breast, an inactive breast and a lactating breast in histology?

Answer 11

Inactive - thick stroma and few glands

Active/pregnant/lactating - lots of glands and diminished stroma