Lactation describes the secretion of milk from the mammary glands and the time period of the breastfeeding mother to feed her child. This process can occur in all female mammals post-pregnancy, although it precedes mammals. In humans the breastfeeding process is also called breastfeeding or breastfeeding . Newborns often produce milk from their own breast tissue, known everyday as witch milk.
In most species, milk comes out of the nipple; However, monotremes, mammals lay their eggs, have no nipples and release milk through the ducts in the abdomen. Only one mammal species, the Dayak fruit bats, is a normal male dairy production.
Galactopoiesis is the maintenance of milk production. This stage requires prolactin. Oxytocin is very important for the let-down reflex in response to breastfeeding. Galactorrhoea is the production of milk unrelated to nursing. May occur in men and women of many mammalian species as a result of hormonal imbalances such as hyperprolactinaemia.
Video Lactation
Destination
The main function of lactation is to provide nutrition and immune protection to the young after birth. In almost all mammals, lactation induces periods of infertility (in humans, amenorrhea lactation), which serves to provide optimal birth spacing for the survival of offspring.
Maps Lactation
Man
Hormonal effects
From the eighteenth week of pregnancy (the second and third trimesters), the female body produces hormones that stimulate the growth of the milk ducting system in the breast:
- Progesterone affects the growth of alveoli and lobe size; High levels of progesterone inhibit lactation before birth. Progesterone levels decline after birth; this leads to excessive milk production.
- Estrogen stimulates the ducting system to grow and differentiate. Like progesterone, high estrogen levels also inhibit lactation. Estrogen levels also decrease during childbirth and remain low during the first few months of breastfeeding. Breastfeeding mothers should avoid the estrogen-based contraceptive method, as the spike in estrogen levels can reduce the mother's milk supply.
- Prolactin contributes to increased growth and differentiation of alveoli, and also affects the differentiation of ductal structures. High levels of prolactin during pregnancy and lactation also increase insulin resistance, increase growth factor level (IGF-1) and modify lipid metabolism in preparation for breastfeeding. During breastfeeding, prolactin is a major factor that maintains tight intersections of the ductal epithelium and regulates the production of breastmilk via an osmotic balance.
- human placental lactogen (HPL) - from the second month of pregnancy, the placenta releases large amounts of HPL. This hormone is closely related to prolactin and appears to play a role in the growth of breast, nipple, and areola before birth. Follicle stimulating hormone (FSH), luteinizing hormone (LH), and human chorionic gonadotropin (hCG), through control of estrogen and progesterone production, and also, by extension, prolactin and production of growth hormone, are essential.
- Growth hormone (GH) is structurally very similar to prolactin and independently contributes to its galactopoiesis.
- Adrenocorticotropic hormone (ACTH) and glucocorticoids such as cortisol have important lactation-inducing functions in some animal species, including humans. Glucocorticoids play a complex regulatory role in the maintenance of tight intersections.
- Thyroid-stimulating hormone (TSH) and thyrotropin-releasing hormone (TRH) is a very important galactopoietic hormone whose levels increase naturally during pregnancy.
- Oxytocin contracts the smooth muscle of the uterus during and after birth, and during orgasm (s). After birth, oxytocin binds the smooth muscle layer of cells like the band that surrounds the alveoli to squeeze the newly-produced milk into the duct system. Oxytocin is required for a milk exclusion expenditure, or let-down, in response to suckling, occurring.
It is also possible to induce lactation without pregnancy. The protocol for inducing lactation is called the Goldfarb protocol. Using birth control pills to mimic pregnancy hormone levels, then stop birth control, followed by the use of dual electric breast pumps for 15 minutes of sessions at regular intervals of 2-3 hours (total of 100 minutes per day) _ help induce milk. production.
Secret differentiation
During the latter part of the pregnancy, the female breast enters the Differentiation Secret stage. This is when the breast makes colostrum (see below), thick fluid, sometimes yellowish. At this stage, high levels of progesterone inhibit most milk production. It is not a medical problem if a pregnant woman secretes colostrum before the birth of her baby, nor is it an indication of future milk production.
Secretarial activation
At birth, prolactin levels remain high, while placental delivery causes a sudden decrease in progesterone, estrogen, and HPL levels. This sudden withdrawal of progesterone in the presence of high levels of prolactin stimulates excessive milk production from Secret Activation .
When the breast is stimulated, the level of prolactin in the blood rises, reaches its peak about 45 minutes, and returns to the previous breastfeeding state about three hours later. The release of prolactin triggers cells in the alveoli to make milk. Prolactin also transfers to breast milk. Several studies have shown that prolactin in milk is greater when milk production is higher, and lower when breasts are fuller, and the highest rates tend to occur between 2 am and 6 am.
Other hormones - especially insulin, thyroxine, and cortisol - are also involved, but their role is not well understood. Although biochemical markers indicate that Secret Activation begins about 30-40 hours after birth, the mother usually does not begin to feel increased breast fullness (milk sensation "comes in the breast") to 50-73 hours (2-3 days) after birth.
Colostrum is the first milk given breast milk. It contains higher levels of white blood cells and antibodies than boiled milk, and is especially high in immunoglobulin A (IgA), which lines the immature baby's lining of the intestine, and helps prevent pathogens from invading the baby system. Secretory IgA also helps prevent food allergies. During the first two weeks after birth, the production of colostrum is slowly giving way to mature breast milk.
Autocrine control - Galactapoiesis
The hormonal endocrine control system encourages the production of breast milk during pregnancy and the first few days after birth. As milk supplies are more stable, the autocrine (or local) control system begins.
During this stage, the more milk is removed from the breast, the more breast milk will produce. Research also shows that drying the breasts more fully also increases the rate of milk production. So the milk supply is greatly influenced by how often the baby suckles and how well he is able to transfer breast milk from the breast. Low inventories can often be tracked to:
- not feeding or pumping often enough
- Infant's inability to remove milk effectively caused by, among others:
- jaw or deficit mouth structure
- bad sticky techniques
- rare maternal endocrine disorders
- hypoplastic breast tissue
- Inadequate calorie intake or maternal malnutrition
Reflection of milk ejection
This is the mechanism by which milk is transported from the breast alveoli to the nipple. Breastfeeding by infants stimulates the paraventricular nucleus and supraoptic nuclei in the hypothalamus, which signals the posterior pituitary gland to produce oxytocin. Oxytocin stimulates the contraction of myoepithelial cells surrounding the alveoli, which already have milk. The increased pressure causes milk to flow through the duct system and is released through the nipple. This response can be conditioned such as the baby's cry.
The expulsion of milk begins in the breast of the mother with the action of suckling by the baby. The reflection of milk expenditure (also called let-down reflexes) is not always consistent, especially at first. After a woman is conditioned to breastfeed, the let-down can be triggered by various stimuli, including the baby's voice. Even thinking about breastfeeding can stimulate this reflex, causing unwanted leaks, or both breasts can secrete breast milk when the baby is breastfeeding from one breast. However, these and other problems often persist after two weeks of breast-feeding. Stress or anxiety can cause difficulties with breastfeeding. The release of the oxytocin hormone leads to milk ejection or let-down reflex . Oxytocin stimulates the muscles around the breast to squeeze the milk. Breastfeeding mothers describe the sensations differently. Some feel a little tingling, others feel enormous pressure or little pain/discomfort, and others do not feel anything different.
Poor milk expenditure reflexes can be caused by sore or cracked nipples, separation of the baby, history of breast surgery, or tissue damage from previous breast trauma. If a mother has difficulty breastfeeding, various methods to help reflex breastfeeding expenditure may be helpful. This includes feeding in a familiar and convenient location, massage your breast or back, or warm your breasts with a cloth or shower.
Mechanism of milk exclusion refresh
This is the mechanism by which milk is transported from the breast alveoli to the nipple. Sucked by baby innervates slowly adapt and quickly adapt the dense mechanoreceptors around the areolar region. The electrical impulse follows the spinotalamic tract, which begins with the innervation of the fourth intercostal nerve. The electrical impulse then rises to posterolateral channels for one or two vertebral and synaptic levels with second-order neurons, called tract cells, posterior to the dorsal horn. The tractate cells then undergo decusation via white anterior commissures to the anterolateral angles and ascend to the supraoptic nuclei and the paraventricular nucleus in the hypothalamus, where they synapse with a third-order oxytocinergic neuron. The remainder of these neurons lies in the hypothalamus, but the axons and axon terminals are located in the infundibulum and pars nervosa of the posterior pituitary, respectively. Oxytocin is produced in soma neurons in the supraoptic and paraventricular nuclei, and is then transported via the infundibulum via the hypothalamus-neurohypophyseal channel with the aid of carrier protein, neurophysin I, to the posterior pars nerve nerve, and then stored in the Herring's body, where they are stored until the synapse between neurons second and third order.
After an electrical impulse, oxytocin is released into the bloodstream. Through the bloodstream, oxytocin enters the myoepithelial cells, which lie between the extracellular matrix and the lumen epithelial cells that also form the alveoli in the breast tissue. When oxytocin binds to the myoepithelial cells, the cells contract. Increased intra-aveolar pressure pressure forcing into the lactiferous sinus, into the lactiferous ducts (a study found that lactiferous sinuses may be absent, if this is true then the milk only enters the lactiferous duct), and then the nipple exits.
Afterpains
Oxytocin surges also cause the uterus to contract. During breastfeeding, the mother may feel this contraction as afterpains . This can vary from cramps such as periods to strong contractions such as labor and can be more severe with the second and subsequent babies.
Tanpa kehamilan, laktasi yang diinduksi, relaktasi
In humans, lactation and induced relactation have been observed frequently in some cultures, and are shown with varying efficacy in adopting mothers. It seems plausible that the possibility of lactation in women (or women of other species) who are not biological mothers does provide an evolutionary advantage, especially in groups with high maternal mortality and strict social ties. This phenomenon has also been observed in most primates, in some lemurs, and in the dwarf fly.
Lactation can be induced in humans by a combination of physical and psychological stimulation, with drugs, or by a combination of such methods. Some couples may stimulate lactation outside of pregnancy for sexual purposes.
A rare male lactation account (different from galactorrhea) is present in medical literature and historical anthropology, although this phenomenon has not been confirmed by the newer literature.
Evolution
Charles Darwin realized that the mammary glands appear to have developed specifically from the skin glands, and hypothesized that they evolved from the glands in the parent pockets of fish, where they would provide food for eggs. The last aspect of the hypothesis has not been confirmed; However, recently the same mechanism has been postulated for early synapsids. Discard fish ( Symphysodon aequifasciata ) is known for (biparentally) feeding their children with epidermal mucus secretions. A closer examination revealed that, as with mammals, the secretion of nutritious fluid of discus fish can be controlled by prolactin.
Like all lactate mammals, lactation must evolve before the last ancestor of all mammals, which places it to a minimum in the Middle Trias or End when monotremes deviate from there. O. T. Oftedal argues that therapsids evolved proto-lacteal fluids to keep eggs moist, an adaptation necessary because diapsid parchment peeled is more susceptible to evaporation and dehydration than mineralized eggs produced by some sauropsids. This protolacteal fluid becomes complex, nutrient-rich milk which then allows the decrease in egg size by reducing dependence on large egg yolks in eggs. [20] The evolution of lactation is also believed to have resulted in more complex teeth seen in mammals, since lactation will allow prolonged jaw development before tooth eruption.
During the initial evolution of lactation, milk secretion is carried through the pilosebaceous glands in the breast patch, analogous to the areola, and the hair in this patch transports nutritious fluids to the eggs as seen on marsupials. Lately the development of the nipple makes mammalian hair becomes obsolete. [2]
Another well-known example of the young nutritious with gland secretions is the milk of the columbiform bird plant. As with mammals and fish disks, this also seems to be directed by prolactin. Other birds such as flamingos and penguins use similar eating techniques.
Lactation is also a hallmark of adenotrophic viviparity - a breeding mechanism developed by some insects, especially tsetse flies. The tse-tse single egg develops into the larvae in the uterus where it is fed by a milk substance secreted by the milk glands in the uterus. The causative species of Diploptera punctata are also known to feed their children with milk secretions.
See also
- Lactation room
- Galactogogue
- The milk line
- Shrimp
- Breastfeeding
- Lactation failure
- Lactation suppression
- Erotic lactation
- The hypothalamic-pituitary-prolactin axis
- Roman charity
References
External links
- How do mammals lose their egg yolks - Do mammals develop nutritional milk before or after they leave yolky eggs? ( New Scientist , March 18, 2008)
Source of the article : Wikipedia
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