Histology of the Breast

Question 1

what is the breast made up of

Answer 1

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

Adjacent to the secretory lobules is dense fibrous tissue, which is surrounded by adipose tissue

Question 2

what is the structure of the duct sytem

Answer 2

Terminal ductules&raquo_space; intralobular collecting duct&raquo_space; the lactiferous duct for that lobe&raquo_space; lactiferous sinus&raquo_space; nipple

Question 3

what is the histology in the larger ducts

Answer 3

lining epithelium is columnar

Question 4

what is the histology of the nipple

Answer 4

covered by highly pigmented keratinized stratified squamous epithelium

core of dense irregular connective tissue mixed with bundles of smooth muscle

Question 5

what are the changes in the breast seen during the luteal phase

Answer 5

epithelial cells increase in height

the lumina of the ducts becomes enlarged

small amounts of secretions appear in the ducts.

Question 6

what are the changes in the breast seen during pregnancy - first trimester

Answer 6

elongation and branching of the smaller ducts

proliferation of the epithelial cells of the glands and the myoepithelial cells.

Question 7

what are the changes in the breast seen during pregnancy - second trimester

Answer 7

glandular tissue continues to develop with differentiation of secretory alveoli

plasma cells and lymphocytes infiltrate the nearby connective tissue

Question 8

what are the changes in the breast seen during pregnancy - third trimester

Answer 8

secretory alveoli continue to mature

development of extensive rough ER

Question 9

what changes occur throughout breast changes in pregnancy

Answer 9

reduction in the amount of connective tissue and adipose tissue present

Question 10

what during pregnancy stimulates the proliferation of secretory tissue and reduction of fibro-fatty tissue

Answer 10

oestrogen and progesterone

Question 11

what is the composition of breast milk

Answer 11

88% water
1.5% protein (mainly lactalbumin and casein)
7% carbohydrate (mainly lactose)
3.5 lipid

Question 12

what importantly is passed through to the baby via breast milk

Answer 12

ions
vitamins
IgA antibodies

Question 13

where are the proteins in the milk made

Answer 13

rER of breast

Question 14

what is merocrine secretion

Answer 14

rER makes protein, packaged in the golgi apparatus and secreted via vesicles

merge with apical membrane and release their contents into the duct system

Question 15

what is apocrine secretion

Answer 15

lipid droplets bud off, surrounded by membrane and carrying a small amount of cytoplasm