Breast histology

Question 1

What kind of gland is the breast

Answer 1

subcutaneous

Question 2

is the breast part of the body wall

Answer 2

no, it sits anterior to it as well as deep fascia and muscles

Question 3

How many lobes make up the secretory tissue of the breast

Answer 3

15-25 lobes

Question 4

what does each lobe consist of

Answer 4

a compound tubulo-acinar gland which drains via ducts leading towards the nipple

Question 5

what are lactiferous ducts and where do they open up to

Answer 5

secretory ducts of the lobe, leading to the nipple

Question 6

what are lobules

Answer 6

tubuloalveolar glands

Question 7

what are lobes

Answer 7

segments of the breast

Question 8

which fibrous bands separate the secretory lobes of the breast
Where are they most pronounced

Answer 8

suspensory ligaments of the breast (of Cooper)

upper breast

Question 9

what are lactiferous sinuses

Answer 9

dilatation in the lactiferous duct near the nipple

Question 10

what does the TDLU stand for

Answer 10

terminal duct lobular unit

Question 11

what is the TDLU

Answer 11

basic functional secretory unit of the breast

aka lobule

Question 12

what kind of connective tissue is found outside the lobule

Answer 12

dense CT

Question 13

what kind of connective tissue is found inside the lobule

Answer 13

loose CT surrounds the acini within the lobule

Question 14

what kind of tissue is found between the lobules

Answer 14

adipose tissue

Question 15

what type of cells are lobules composed of

Answer 15

epithelial cells

Question 16

what kind of secretory epithelial cells line the acini within lobules

Answer 16

cuboidal/columnar

Question 17

what does MEp stand for

Answer 17

myoepithelial cells

Question 18

what are MEp (myoepithelial cells)

Answer 18

contractile epithelial cells that surround secretory cells

they are half way between smooth muscle and epithelial cells

Question 19

function of MEp

Answer 19

to push material out of ductal system by contraction

Question 20

what epithelium lines larger ducts eg lactiferous ducts

Answer 20

stratified squamous more superficially

stratified cuboidal deeper

Question 21

which epithelium covers the nipple

Answer 21

thin pigmented keratinised stratified squamous epithelium

Question 22

is there smooth muscle present in the nipple

Answer 22

yes alongside dense irregular CT

Question 23

what is different about sebaceous glands in the nipple in comparison to the rest of the skin

Answer 23

sebaceous glands in the nipple open up directly on to the surface
in the rest of the skin, they open onto hair follicles first

Question 24

what happens to epithelial cells during the luteal phase

Answer 24

increase in height
lumen becomes enlarged
secretions appear in the duct

Question 25

what happens to cells of the breast during pregnancy

Answer 25

1st trimester - branching of smaller ducts + proliferation of epithelium and MEp
2nd - glandular tissue develops
3rd - secretory alveoli mature

Question 26

which hormones stimulate proliferation of secretory tissue in pregnancy

Answer 26

oestrogen

progesterone

Question 27

what is the composition of human milk

Answer 27

water 88%
protein 1.5%
carbohydrate 7%
lipid 3.5% 
ions, vitamins, IgA

Question 28

which proteins are found in human milk

Answer 28

lactalbumin

casein

Question 29

what are the 3 methods of secretion

which is the most common

Answer 29

Holocrine
Apocrine
Merocrine - most common

Question 30

what is holocrine secretion and where is it seen

Answer 30

contents accumulate in the cell which then bursts open to release material and entire contents of the cell
seen at the nipple

Question 31

what is apocrine secretion

Answer 31

globules of fat free in the cytoplasm are released with a small amount of cytoplasm and membrane surrounding it

Question 32

what is merocrine secretion

Answer 32

material is packaged up into vacuole which merges with the apical cell membrane and opens up
nothing else is released except for the material

Question 33

what happens to secretory cells of TDLU after menopause

Answer 33

they degenerate, leaving only ducts

Question 34

how does the breast differ in males from females

Answer 34

males have a rudimentary duct system but no lobules as they do not need to secrete milk