Breast Histology Flashcards
Each breast lobe consists of a compound tubulo-acinar gland. Approx. how many lobes are there per breast?
15-25 lobes
What interlobular tissues surround the secretory lobules of the breast?
dense fibrocollagenous connective tissue which is then surrounded by adipose tissue between lobes
What are the suspensory ligaments & what do they connect?
fibrous connective tissue bands that extend from the dermis of the skin to the deep fascia over the anterior chest wall muscles
What is the basic functional secretory unit of the breast?
Terminal Duct Lobular Unit (TDLU)
In non-lactating breast, terminal ductules lead where?
into interlobular collecting duct which leads into the lactiferous duct for that lobe which leads to the nipple
What is the lactiferous sinus?
an expanded part of the lactiferous duct near the nipple that acts as resevoir for milk, duct narrows again to exit areola
Which is the fibrocollagenous tissue looser around the acini AKA terminal ductules?
to allow rapid expansion in pregnancy
Contractile epithelial cells surround the secretory cells of the acinus, what are they called?
myoepithelial cells (MEp)
What type of secretory epithelial cells that line the acini?
cuboidal and columnar cells
What type of epithelial cells line the lactiferous duct?
varies, further to nipple is stratified squamous and deeper is stratified cuboidal , may be only 1 cell thick in deep part
How do MEp cells appear on histology sections?
pink lines around the cells
What cells line the outer nipple surface?
thin, highly pigmented keratinised stratified squamous epithelium
What tissue makes up the core of nipples that the lactiferous ducts pass through?
fibrocollagenous tissue mixed with smooth muscle bundles
What glands are found in the skin surface of nipple?
sebaceous glands
What 3 changes occur to mammary gland during the luteal phase of menstrual cycle?
epithelial cells increase in height,
lamina of ducts enlarge,
small amounts of secretions appear in ducts
What 2 changes occur to the mammary glands in first trimester of pregnancy?
elongation & branching of small ducts,
proliferation of epithelial and myoepithelial cells of glands
What 2 changes occur to the mammary glands in second trimester of pregnancy?
glandular tissue develops with differentiation of secretory alveoli,
plasma cells and lymphocytes infiltrate the connective tissue around glands
What change occurs to the mammary glands in third trimester of pregnancy?
secretory alveoli mature with development of extensive rER
What change occurs to breasts during all three trimesters of pregnancy?
Reduction of connective and adipose tissue
What hormones stimulate proliferation of secretory tissue and reduction in fibro-fatty tissue in pregnancy?
Oestrogen and progesterone
Compositions of human milks are approx. 88% ? 7% ? 3.5% ? 1.5% ? small quantities of ?,? and ?
88% water, 7% carbohydrate, 3.5% lipid, 1.5% protein, small quantities of ions, vitamins and IgA
How are lipid droplets secreted from terminal ductules?
Apocrine secretion = surrounded by membrane with small amount of cytoplasm
How are proteins secreted from terminal ductules?
Merocrine secretion = via vesicles which merge with apical membrane to release contents into ducts system
Where are proteins for breast milk are made & packaged?
made in rER and packaged in Golgi apparatus
