lactation (redirected from lactational)

lactation

Production of milk by female mammals after giving birth. The milk is discharged by the mammary glands in the breasts. Hormones triggered by delivery of the placenta and by nursing stimulate milk production. Colostrum (milk that the mother produces in the first few days after giving birth) has more proteins, minerals, and antibodies and fewer calories and fats than the mature milk that develops later. Mature milk supplies nutrients, hormones, and substances that provide the infant with immunity against infectious agents. Most physicians recommend that babies be fed mother's milk exclusively for the first six months and that nursing continue through the first year. As the child is weaned, lactation tapers off; while nursing continues, fertility is reduced. Problems with lactation may involve hormones, suckling pattern, physical difficulties, or emotional factors. Mothers taking certain drugs or with some diseases (e.g., AIDS) should not nurse, because of risks to the baby.

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lactation

1. the secretion of milk from the mammary glands after parturition

2. the period during which milk is secreted

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lactation [lak′tā·shən]

(physiology)

Secretion of milk by the mammary glands.

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Lactation

The function of the mammary gland providing milk nourishment to the newborn mammal. This process is under the control of the endocrine and nervous systems. It involves transformation of an inactive duct system to a lobuloalveolar glandular structure during pregnancy, cellular production of the components of milk (galacto-poiesis), secretion into the ducts, and ejection under the stimulus of milking or suckling.

Lactation makes demands on the maternal regulation of calcium metabolism. Resorption of bone increases in lactating rats and women, and there is a marked increase in the absorption of calcium from the intestine. The elevated need for calcium results in an increased role for parathyroid hormone, calcitonin, and vitamin D in the regulation of the absorption and utilization of calcium. In humans a concomitant phenomenon frequently associated with lactation is amenorrhea. Consequently in some societies prolonged nursing is used as a birth control technique. See Mammary gland, Milk