histology of the breast

Question 1

what type of gland is the breast?

Answer 1

subcutaenous gland

Question 2

secretory tissue of the breast is made up of how many lobes?

Answer 2

15-25 lobes
- each consisting of a compound tubulo-acinar gland which drains via a series of ducts leading to the nipple

Question 3

what is found adjacent to secretory lobules?

Answer 3

• dense fibrous tissue - which in turn is surrounded by adipose tissue

Question 4

Question 5

what are suspensory ligaments?

Answer 5

• extend from dermis of skin to deep fascia overlying muscle of ant chest wall
• function: to support to breast tissue

Question 6

what is the basic functional secretory unit of the breast called?

Answer 6

• terminal duct lobular unit
• in non-lactating breast, terminal ductules -> an intralobular collecting duct -> lactiferous duct for that lobe -> nipple (lactiferous sinus)

Question 7

what is contained within structure of the lobule?

Answer 7

• extralobular and intralobular ducts
• rudimentary secretory acini
• dense fibrocollagenous CT surrounding lobule
• looser connective tissue surrounding acini (allows rapid expansion in pregnancy)
• adipose tissue between lobules

Question 8

within the lobule the secretory epithelial cells that line the acini are what kind of cells?

Answer 8

• cuboidal
• columnar

Question 9

secretory cells of acinus are surrounded by what kind of cells?

Answer 9

• myoepithelial cells (MEp)
  function: contractile epithelial cells and are surrounded by basal lamina

Question 10

larger ducts e.g. lactiferous duct are lined by what kind of epithelium?

Answer 10

• stratified squamous to stratified cuboidal cells

Question 11

nipple is covered by a thin layer of pigmented …. ….. …. epithelium?

Answer 11

• keratinized, stratified, squamous epithelium

Question 12

what structure can be found within the nipple?

Answer 12

• lactiferous ducts
  : serve one lobe of the breast

Question 13

what change occurs to epithelial cells during the luteal phase?

Answer 13

• cells inc in height

Question 14

what changes occur to ducts during the luteal phase?

Answer 14

• lumina of the ducts enlarges
• small amounts of secretions appear in the ducts

Question 15

1st trimester of pregnancy what changes occur to ducts, glands?

Answer 15

• elongation and branching of smaller ducts
• proliferation of epithelial cells of glands
• proliferation of myoepithelial cells

Question 16

2nd trimester what changes occur to glandular tissue?

Answer 16

continues to develop w differentiation of secretory alveoli
plasma cells and lymphocytes infiltrate nearby connective tissue

Question 17

3rd trimester what occurs to glandular tissue of breast?

Answer 17

• seretory alveoli continue to mature
• development of extensive rER

Question 18

during pregnancy there is a reduction in the amount of connective tissue and adipose tissue true or false?

Answer 18

true

Question 19

what 2 hormones stimulate proliferation of secretory tissue during pregnancy?

Answer 19

• oestrogen and progesterone

Question 20

milk is made up of predominantly what substance?

Answer 20

• 88% water

Question 21

what antibodies are found in human milk?

Answer 21

• IgA antibodies

Question 22

what is apocrine secretion?

Answer 22

• when lipid droplets are secreted surrounded by membrane and carrying small amount of cytoplasm with it

Question 23

what is merocrine secretion?

Answer 23

• exocytosis
• process by which protein packaged in golgia apparatus is secreted via vesicles and merges with apical membrane to release only their contents into the duct system

Question 24

proteins in milk are made where?

Answer 24

rER

Question 25

following menopause what happens to secretory cells of the TDLU?

Answer 25

• they degenerate leaving only ducts
• fewer fibroblasts
• reduced collagen and elastic fibres

Question 26

what is the blood supply to the breast tissue?

Answer 26

• lateral mammary branches from lateral thoracic a
• medial mammary branches from internal thoracic a

Question 27

what veeins are involved in the venous drainage of breast?

Answer 27

• medial and lateral mammary veins

Question 28

what vessels are involved in the venous drainage of the breast?

Answer 28

• medial and lateral mammary veins

Question 29

where does the majority of lymph drain from the breast to?

Answer 29

• axillary lymph nodes 75%
  -> remainder to parasternal nodes
  -> some may also drain to abdominal nodes