* '''Involution''': termination of milk secretion and mammary gland regression.
* '''Involution''': termination of milk secretion and mammary gland regression.
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[[Category:Lactation]]
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==Involution==
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* As the requirement for milk by the neonate decreases, suckling is less frequent.
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* Consequently, there is a buildup of pressure in the mammary gland causing secretory cells to become increasingly less functional - '''pressure atrophy'''.
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* Secretory cells then remain non-functional until a subsequent pregnancy, at which time prolactin, glucocorticoids and placental lactogen restimulate alveolar milk synthesis.
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* During involution, immune cells such as lymphocytes and macrophages invade the mammary tissue. These produce immunoglobulins in the subsequent lactation.
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* Involution is critical to allow the replacement of senescent secretory cells which are lost by apoptosis.
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* In rodents, '''defoliation''' occurs. Secretory epithelial cells are sloughed from the basement membrane at involution. Thus, more extensive regeneration is required at the onset of the subsequent lactation.
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==Associated Pathology==
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* Information on '''Hypocalcaemia 'Milk Fever'''' can be found [[General Pathology - Vascular Fluid Balance - Pathology#Calcium|here]]
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* Information on '''Mammary Neoplasia''' can be found [[Neoplasia - Pathology#Examples of Tumour Types|here]]
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* Information on '''Mastitis''' can be found [[Healing and Repair - Pathology#Female|here]]