Structure Mammary gland
the basic components of mature mammary gland alveoli (hollow cavities, few millimeters large) lined milk-secreting cuboidal cells , surrounded myoepithelial cells. these alveoli join form groups known lobules. each lobule has lactiferous duct drains openings in nipple. myoepithelial cells contract under stimulation of oxytocin, excreting milk secreted alveolar units lobule lumen toward nipple. infant begins suck, oxytocin-mediated let down reflex ensues , mother s milk secreted — not sucked gland — baby s mouth.
all milk-secreting tissue leading single lactiferous duct called simple mammary gland ; in complex mammary gland simple mammary glands serve 1 nipple. humans have 2 complex mammary glands, 1 in each breast, , each complex mammary gland consists of 10–20 simple glands. presence of more 2 nipples known polythelia , presence of more 2 complex mammary glands polymastia.
maintaining correct polarized morphology of lactiferous duct tree requires essential component – mammary epithelial cells extracellular matrix (ecm) which, adipocytes, fibroblast, inflammatory cells, , others, constitute mammary stroma. mammary epithelial ecm contains myoepithelial basement membrane , connective tissue. not support mammary basic structure, serve communicating bridge between mammary epithelia , local , global environment throughout organ s development.
histology
light micrograph of human proliferating mammary gland during estrous cycle. sprouting gland tissue can seen in upper left field (haematoxylin eosin staining)
a mammary gland specific type of apocrine gland specialized manufacture of colostrum when giving birth. mammary glands can identified apocrine because exhibit striking decapitation secretion. many sources assert mammary glands modified sweat glands. authors dispute , argue instead sebaceous glands.
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