Breast Histology and Anatomy Flashcards
what makes up the secretory tissue of the breast
lobes- divided into lobules by dense connective tissue
15-25 lobules - each has a tubulo-acinae gland which drains via a series of ducts to the nipple
what surrounds the secretory tissues of the breast
dense connective tissue
this is surrounded by adipose tissue
what is the lactiferous sinus
expansion of the lactiferous duct before it reaches the nipple
what are the suspensory ligaments of the breast
connective tissue that extends from dermis of skin to deep fascia overlying the muscle of ant chest wall
support the breast tissue
what is the basic functional secretory unit of the breast
the terminal duct lobular unit
what does the terminal ductules lead to in a non lactating breast
intralobular collecting duct which leads into the lacteiferous duct for that lobe
what does the lacteriferous duct lead to
the nipple
what proliferates in a lactating breast
terminal duct lobular unit
what structures are associated with lobule
Both extralobular and intralobular ducts
Rudimentary secretory acini
Dense fibrocollagenous connective tissue surrounding the lobule
Looser connective tissue surrounding the acini within the lobule (this allows rapid expansion in pregnancy)
Adipose tissue between lobules
what cells line the acini
secretory epithelial cells
vary from cuboidal to columnar
what are the myoepithelial cells of the breast
surround the secretory cells that line the acini
are contractile epithelial cells (are surrounded by basil lamina) that work to push material our o the duct system
what is an acnini
termonal ductal lobular unit
what does loos connective tissue in the mammary gland allow
proliferation
what lines lactiferous ducts
epithelium that varies from thin stratified squamous (as reaches surface of nipple) to stratified cuboidal (deeper)
what is the histology of the nipple
surface is highly pigmented, keratinized squamous epithelium
core is dense irregular connective tissue mixed with smooth muscle bundles
will contain several latiferous ducts
sebaceous glands open directly onto skin as have no hair (holocrine excretion- cell explodes)
what happens to the breast during menstruation
in luteal phase epithelual cells increase in height- enlarging lumina of the ducts
small amounts of secretions appear in the ducts
what happens to the breast in pregnancy
1st trim- elongation and branching of smaller ducts, proliferation of epithelial cells of glands and of myoepithelium
2nd trim- glandular tissue continues to develop: differentiation of secretory alveoli, plasma cell and lymphocyte infiltrate nearby connective tissue
3rd trim- secretory alvioli mature, development of extensive rough endoplasmic reticulum
also reduction in connective and adipose tissue
what are alveoli
acini
what are the effects of oestrogen and progesterone on the breast
stimulate proliferation of secretory tissue and fibro fatty tissue becomes sparse
what is the composition of human milk
88% water
1.5% protein (lactalbumin and casein)
7% carbohydrate (mainly lactose)
3.5% lipid
small quantities of ions, vitamins and IgA antibodies
how is the lipid component of breast milk secreted
apocrine secretion= Lipid droplets are secreted surrounded by membrane and carrying a small amount of cytoplasm with it
how are the proteins in milk made
made in rER
packaged in golgi apparatus
how are the proteins in milk secreted
merocrine secretion (exocytosis) secreted via vesicles which merge with the apical membrane to release only their contents into the duct system only proteins are secretion, no membrane or cytoplasms alongside
what happens to the breast following menopause
secretory cells of TDLU degenerate leaving only ducts
reduced fibroblasts, collagen and elastic fibres in connective tissue
can males get breast cancer
yes have rudimentary element of duct system so have small amounts of epithelium
what is breast cancer in situ
still within duct (ductal is a common form of breast cancer)
