Archive:Lactocyte: Difference between revisions
→Milk secretion and regulation: Replacing controversial claim and primary research paper with context and book reference |
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==Structure== | ==Structure== | ||
Mammary glands contain alveoli. Inside the alveoli of lactating females, a bulb-like lumen is lined by lactocyte cells, which secrete milk into the lumen, which is then squeezed out of the lobules, or groups of alveoli, into milk ducts as the infant suckling triggers muscle contractions.<ref>{{Cite web |title=NDC {{!}} Lactogenesis: secretory differentiation and activation of the human mammary gland |url=https://ndcinstitute.au/article/d9d9a92d-471b-4c1b-80de-bdc49cc3fc5f/lactogenesis-secretory-differentiation-and-activation-of-the-human-mammary-gland |access-date=2026-09-11 |website=ndcinstitute.au}}</ref> Nerve fibers near the areolar region respond to suckling and initiate a neuroendocrine reflex that initiates secretion of milk from lactocytes into the alveoli.<ref>{{Cite web |title=Lactation {{!}} Anatomy and Physiology II |url=https://courses.lumenlearning.com/suny-ap2/chapter/lactation/ |access-date=2026-09-11 |website=courses.lumenlearning.com}}</ref> | Mammary glands contain alveoli. Inside the alveoli of lactating females, a bulb-like lumen is lined by lactocyte cells, which secrete milk into the lumen, which is then squeezed out of the lobules, or groups of alveoli, into milk ducts as the infant suckling triggers muscle contractions.<ref name="ndcinstitute">{{Cite web |title=NDC {{!}} Lactogenesis: secretory differentiation and activation of the human mammary gland |url=https://ndcinstitute.au/article/d9d9a92d-471b-4c1b-80de-bdc49cc3fc5f/lactogenesis-secretory-differentiation-and-activation-of-the-human-mammary-gland |access-date=2026-09-11 |website=ndcinstitute.au}}</ref> Nerve fibers near the areolar region respond to suckling and initiate a neuroendocrine reflex that initiates secretion of milk from lactocytes into the alveoli.<ref>{{Cite web |title=Lactation {{!}} Anatomy and Physiology II |url=https://courses.lumenlearning.com/suny-ap2/chapter/lactation/ |access-date=2026-09-11 |website=courses.lumenlearning.com}}</ref> | ||
==Origin and stages== | ==Origin and stages== | ||
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Before pregnancy, the ductal tissue of the adult mammary gland is composed of epithelial cells of three broad types.<ref name=Gray2025/> The innermost layer consists of two types: the ''luminal hormone sensing'' (LHS) cells and the ''luminal adaptive secretory precursor'' (LASP) cells. This layer is then surround by a second layer composed of ''basal-myoepithelial'' (B-myo) cells.<ref name=Gray2025/> During pregnancy, the LHS cells receive signals from hormones (especially [[estrogen]], [[progesterone]], [[prolactin]], and [[human placental lactogen]]) and pass these signals onto nearby LASP cells, which subsequently differentiate into lactocytes.<ref name=Gray2025/> | Before pregnancy, the ductal tissue of the adult mammary gland is composed of epithelial cells of three broad types.<ref name=Gray2025/> The innermost layer consists of two types: the ''luminal hormone sensing'' (LHS) cells and the ''luminal adaptive secretory precursor'' (LASP) cells. This layer is then surround by a second layer composed of ''basal-myoepithelial'' (B-myo) cells.<ref name=Gray2025/> During pregnancy, the LHS cells receive signals from hormones (especially [[estrogen]], [[progesterone]], [[prolactin]], and [[human placental lactogen]]) and pass these signals onto nearby LASP cells, which subsequently differentiate into lactocytes.<ref name=Gray2025/> | ||
Following secretory differentiation, pregnancy hormones suppress the lactocytes, reducing their size and function. Upon delivery of the placenta, the resulting significant drop in progesterone allows prolactin to stimulate milk synthesis and secretion in the alveoli. Initially, there are large intercellular gaps between lactocytes, allowing high transfer of maternal plasma components to enter the milk, and colostrum - the initial, immature, and highly beneficial milk - is produced. As the intercellular gaps are bridged by an apical junctional complex and the number of lactocytes increase, they begin to produce "mature" [[breast milk]].<ref name=":1">{{Cite web |last=Physiology |first=Fetal and Neonatal |date=2024-03-22 |title=Drug Transfer During Breastfeeding |url=https://clinicalpub.com/drug-transfer-during-breastfeeding/ |access-date=2026-09-11 |website=Clinical Tree |language=en-US}}</ref><ref | Following secretory differentiation, pregnancy hormones suppress the lactocytes, reducing their size and function. Upon delivery of the placenta, the resulting significant drop in progesterone allows prolactin to stimulate milk synthesis and secretion in the alveoli. Initially, there are large intercellular gaps between lactocytes, allowing high transfer of maternal plasma components to enter the milk, and colostrum - the initial, immature, and highly beneficial milk - is produced. As the intercellular gaps are bridged by an apical junctional complex and the number of lactocytes increase, they begin to produce "mature" [[breast milk]].<ref name=":1">{{Cite web |last=Physiology |first=Fetal and Neonatal |date=2024-03-22 |title=Drug Transfer During Breastfeeding |url=https://clinicalpub.com/drug-transfer-during-breastfeeding/ |access-date=2026-09-11 |website=Clinical Tree |language=en-US}}</ref><ref name="ndcinstitute" /> | ||
==Milk secretion and regulation== | ==Milk secretion and regulation== | ||