Breast anatomy and histology Flashcards
Describe the basic structure of non-lactating breast
Made up of 15-25 lobes, each consisting of a compound tubulo-acinar gland which drains via a series of ducts leading to the nipple
What is adjacent to the secretory tissue?
Dense fibrous tissue surrounded by adipose tissue
Describe the duct system
Terminal ductules lead into an intralobular duct which leads into the lactiferous duct for that lobe.
The lactiferous ducts leads to the nipple, passing through an expanded duct region near the nipple termed the lactiferous sinus
Where is the epithelium columnar?
In the larger ducts
Where is the epithelium cuboidal or low columnar?
In secretory acini
What are the nipples covered by?
highly pigmented kerotinized stratified squamous epithelium
What makes up the core of the nipple?
Dense, irregular connective tissue mixed with bundles of smooth muscle
what happens to the duct as it approaches the surface?
It becomes lined by stratified squamous epithelium, deeper, it is lined by stratified cuboidal epithelium
What is present at the deepest layer?
One cell thick lining
What happens to the breast during the menstrual cycle? (non pregnant)
During luteal phase: epithelial cells increase in height, the lumina of the ducts becomes enlarged and small amounts of secretions appear in the ducts
What happens in pregnancy to the breast in the first trimester?
1st trimester: elongation and branching of the smaller ducts, combined with proliferation of the epithelial cells of the glands and the myoepithelial cells.
What happens to the breast in the second trimester?
In 2nd trimester, glandular tissue continues to develop with differentiation of secretory alveoli. Also plasma cells and lymohocytes infiltrate the nearby connective tissue
What happens i the third trimester to the breast?
Secretory alveoli continue to mature, with developmental of extensive rER
What other changes occur in the breast during pregnancy?
Reduction in amount of connective and adipose tissue
What stimulates proliferation of secretory tissue and causes fibro-fatty tiisue becomes sparse
Oestrogen and progesterone
