Mammary_histophys Flashcards
mammary gland hist
branching duct system of glandular epithelium
gland is compound tubulo-alveolar gland ( glandular elements, ductal elements, subcut CT stroma
hist features of nipple and arola
SS-keratinized, no follicles, tall dermal papillae
numerous melanocytes that give dark pigment (esp during pregnancy)
underlying dense irregular CT with abundant elastic fibers
sebaceous glands
***meissner and pacinian corpuscles
lactiferous ducts
formed by individual ductule (which arise from a single alveolus)
form lactiferous sinus at the nipple duct
** may be stratified cuboidal epithelium with layer of myoepithelial ducts
lactiferous alveoli
functional unit of mammary gland is lobule
simple columnar epi with rough ER, golgi, secretion granules (esp in lactating gland)
alveoli cluster around an alvolar ductule =lobule
lobule
functional unit of the mammary gland
formed up clusters of alveoli surrounded by an alvolar ductule
stroma of mammary gland
stroma varies from dense irregular to loose irregular interlobular CT
loose facilitates growth and expansion of alveolus
interlobular CT
dense, separates lobes and lobules
structural support for breast
intralobular CT
loose, surrounds and separates alveoli, allows for expansion during lactation
innervation to mammary gland
superficial ( areola and nipple): rich sensory neurons
myoepithelial cells are not innervated, activated by oxytocin***
fetal and neonate mammogenesis
initial appearance at 6th week of gestation: mammary ridges from ectoderm
primitive duct system (15-2- ducts in both males and tissues0
pubertal mammogenesis
further growth and branching of ductal system
E2ā> elaborates duct system
Pā>alveoli develop
increased adiposity and CT proliferation
same effects seen during menstrual cycle
breast cancer: premenopausal
treatment is inhibition of selective estrogen receptor modulator
antagonizes E2 on the breast, agonizes at bone and uterus
lactogenic hormones
Prl
hPL
mammogenic hormones
Prl and estrogens
oxytocin
galactokinetic (milk ejection)
promotes contraction of myoepithelial cells resulting in milk ejection
increased synthesis and release via positive feedback caused by suckling, nursing, and audiovisual stimuli
4 stages of lactation
1) milk synth: Prl and hPL in preg
2) lactogenesis: from alveolar cells into lumen after birth
3) galactopoiesis: maintenance of lactation (Prl)
4) milk ejection: oxy
milk ejection
alveolar milk accumulates within the sinuses or ampullae
negative emotions can inhibit oxytocin and suppress milk ejection
milk ejeciton loop
1) suckling stimulus
2) inhibition of DA by PIF from hypothalamus
increases prl secretion
3) stimulates hypothalamic oxy production and release from post pit
4) inhibition of hypothalamic production of GnRH (dec LH, FSH, and ovarian cycle)
colostrum
thin yellowish milk stuff that is secreted in the first few days of parturition. High concentration of Igs (IgA)
human mild
emlsion of fats in an aw Na containing sugar, proteins, and ions
lots more fat than cows milk with less protein
