Breast histology* Flashcards
how many lobes is the secretary breast tissue made of
15-25
what each lobe consist of
compound tubulo acinar gland which drains via a series of ducts leading to the nipple
what is adjacent to the secretory lobules and what is it surrounded by
dense fibrous tissue surrounded by adipose tissue
what are suspensor ligaments of cooper
increased condensations of fibrocollagenous tissue that extend to the dermis of the skin and support the breast
where do the lactiferous ducts start and end
branch from each lobule and end at the end of the nipple
what do terminal ducts lead into and then what and then
interlobular collecting duct and then extra lobular collecting duct which then leads to lactiferous duct. this then leads to the nipple and passes through a sinus
what is the lactiferous sinus
the duct expands for a short distance and then gets smaller again - allows a reserver for milk to build up for breastfeeding
what is the lining of larger ducts
columnar epithelium
what is the lining of secretary acini
cuboidal or low columnar epithelium
what are both larger ducts and secretary acini surrounded by
myoepithelial cells - contractile epithelial cells
what do breast glands look similar to
sweat glands
what is the nipple covered by
high pigmented keratinized stratified squamous epithelium
what is the core of the nipple
dense irregular connective tissue mixed with bundles of smooth muscle
why is smooth muscle in the core of the nipple
for nipple erection
what can be seen in a transverse section through the nipple (2)
lactiferous sinuses
sebaceus glands which produce oil to help with the protection of the nipples during breastfeeding
what happens to the lining of the lactiferous duct as it reaches the surface
changes from being one cell thick to stratified columnar epithelium to stratified squamous epithelium
what happens to the epithelial cells during the luteal phase
increase in height
lamina of ducts becomes enlarged and small secretions appear in ducts
changed in the mamary glands during the first trimester
elongation and branching of the smaller ducts and proliferation of the epithelial cells of the glands and the myoepithelial cells
what changes occur in the second trimester to the mammary gland
tissue continues to develop with differentiation of secretory alveoli
plasma cells and lymphocytes infiltrate the nearby connective tissue
what changes occur in the third trimester in the mammary gland
alveoli continue to mature with development of extensive rER
what are changes to the mammary gland accompanied
reduction in the amount of connective tissue and adipose tissue present
what happens during pregnancy in terms of hormone production
oestrogen and progesterone stimulate proliferation of secretory tissue and fibre fatty tissue becomes sparse
composition of human milk
88% water
1.5% protein (daily lactalbumin and casein)
7% carbohydrate (daily lactose)
3.5% lipid
small amounts of ions, vitamins and IgA antibodies
how does apocrine secretion take place
lipid droplets bud off from mammary acini and end up as almost vesicles with surrounding membrane
how does merocrine secretion take place
proteins in milk are made rER packaged by golgi and secreted as vesicles which merge with apical membrane to release their content into the duct system
what happens to the secretory cells of the TDLU following menopause and what happens to the connective tissue
secretory cells degenerate leaving one ducts
connective tissue - fewer fibroblasts and reduced collagen and elastic fibres
