Placenta – wikipedia electricity 2pm live

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The placenta is a temporary organ that connects the developing fetus via the umbilical cord to the uterine wall to allow nutrient uptake, thermo-regulation, waste elimination, and gas exchange via the mother’s blood supply; to fight against internal infection; and to produce hormones which support pregnancy. Placentas are a defining characteristic of placental mammals, but are also found in marsupials and some non-mammals with varying levels of development. [1]

The placenta functions as a fetomaternal organ with two components: [2] the fetal placenta ( Chorion frondosum), which develops from the same blastocyst that forms the fetus, and the maternal placenta ( Decidua basalis), which develops from the maternal uterine e sampark electricity bill payment tissue. [3] It metabolizes a number of substances and can release metabolic products into maternal or fetal circulations. The placenta is expelled from the body upon birth of the fetus.

The word placenta comes from the Latin word for a type of cake, from Greek πλακόεντα/πλακοῦντα plakóenta/plakoúnta, accusative of πλακόεις/πλακούς plakóeis/plakoús, flat, slab-like, [4] [5] in reference to its round, flat appearance in humans. The classical plural is placentae, but the form placentas is common in modern English and probably has the wider currency at present.

Placental mammals, such as humans, have a chorioallantoic placenta that forms from the chorion and allantois. In humans, the placenta averages 22 cm (9 inch electricity for dummies amazon) in length and 2–2.5 cm (0.8–1 inch) in thickness, with the center being the thickest, and the edges being the thinnest. It typically weighs approximately 500 grams (just over 1 lb). It has a dark reddish-blue or crimson color. It connects to the fetus by an umbilical cord of approximately 55–60 cm (22–24 inch) in length, which contains two umbilical arteries and one umbilical vein. [6] The umbilical cord inserts into the chorionic plate (has an eccentric attachment). Vessels branch out over the surface of the placenta and further divide to form a network covered by a thin layer of cells. This results in the formation of villous tree structures. On the maternal side, these villous tree structures are grouped into lobules called cotyledons. In humans, the placenta usually has a disc shape, but size varies vastly between different mammalian species. [7]

The placenta occasionally takes a form in which it comprises several distinct parts connected by blood vessels. [8] The parts, called lobes, may number two, three, four, or more. Such placentas are described as bilobed/bilobular/bipartite, trilobed/trilobular/tripartite, and so on. If there is a clearly discernible main lobe and up electricity bill payment online auxiliary lobe, the latter is called a succenturiate placenta. Sometimes the blood vessels connecting the lobes get in the way of fetal presentation during labor, which is called vasa previa.

The placenta intermediates the transfer of nutrients between mother and fetus. The perfusion of the intervillous spaces of the placenta with maternal blood allows the transfer of nutrients and oxygen from the mother to the fetus and the transfer of waste products and carbon dioxide back from the fetus to the maternal blood. Nutrient transfer to the fetus can occur via both active and passive transport. [22] Placental nutrient metabolism was found to play a key role in limiting the transfer of some nutrients. [23] Adverse pregnancy situations, such as those involving maternal diabetes or obesity, can increase or decrease levels of nutrient transporters in the placenta potentially resulting in overgrowth or restricted growth of the fetus. [24] Excretion [ edit ]

IgG antibodies can pass through the electricity facts label human placenta, thereby providing protection to the fetus in utero. [25] This transfer of antibodies begins as early as the 20th week of gestational age, and certainly by the 24th week. [26] This passive immunity lingers for several months after birth, thus providing the newborn with a carbon copy of the mother’s long-term humoral immunity to see the infant through the crucial first months of extrauterine life. IgM, however, cannot cross the placenta, which is why some infections acquired during pregnancy can be hazardous for the fetus gas usa.

• The first hormone released by the placenta is called the human chorionic gonadotropin hormone. This is responsible for stopping the process at the end of menses when the Corpus luteum ceases activity and atrophies. If hCG did not interrupt this process, it would lead to spontaneous abortion of the fetus. The corpus luteum also produces and releases progesterone and estrogen, and hCG stimulates it to increase the amount that it releases. hCG is the indicator of pregnancy that pregnancy tests look for. These tests will work when menses has not occurred or after implantation has happened on days seven to ten. hCG may also have an anti-antibody effect, protecting it from being rejected by the mother’s body. hCG also assists the male fetus by stimulating the testes to produce testosterone, which is the hormone needed done with electricity tattoo book to allow the sex organs of the male to grow.

• Progesterone helps the embryo implant by assisting passage through the fallopian tubes. It also affects the fallopian tubes and the uterus by stimulating an increase in secretions necessary for fetal nutrition. Progesterone, like hCG, is necessary to prevent spontaneous abortion because it prevents contractions of the uterus, and is necessary for implantation.

• Estrogen is a crucial hormone in the process of proliferation. This involves the enlargement of the breasts and uterus, allowing for growth of the fetus and production of milk. Estrogen is also responsible for increased blood supply towards the end of pregnancy through vasodilation. The levels of estrogen during pregnancy can increase so that they are thirty times what a non-pregnant woman mid-cycles estrogen level would be.

• Human placental lactogen is a hormone used in pregnancy to develop fetal metabolism gas under a dollar and general growth and development. Human placental lactogen works with Growth hormone to stimulate Insulin-like growth factor production and regulating intermediary metabolism. In the fetus, hPL acts on lactogenic receptors to modulate embryonic development, metabolism and stimulate production of IGF, insulin, surfactant and adrenocortical hormones. hPL values increase with multiple pregnancies, intact molar pregnancy, diabetes and Rh incompatibility. They are decreased with toxemia, choriocarcinoma, and Placental insufficiency. [27] [28]

Some cultures bury the placenta for various reasons. The Māori of New Zealand traditionally bury the placenta from a newborn child to emphasize the relationship between humans and the earth. [34] Likewise, the Navajo bury the placenta and umbilical cord at a specially chosen site, [35] particularly if the baby dies during birth. [36] In Cambodia and Costa Rica, burial of the placenta is believed to protect and ensure the health of the baby and the mother. [37] If a mother dies in childbirth, the Aymara of Bolivia bury the placenta in a secret place so that the mother’s spirit will not return to claim her baby’s life. [38]

The placenta is believed by some communities to have power over the lives of the baby or its parents. The Kwakiutl of British Columbia bury girls’ placentas to give the girl skill in digging clams, and expose boys’ placentas to ravens to encourage future prophetic visions. In Turkey, the proper disposal of the placenta and umbilical cord is believed to promote devoutness in the child later in life. In Ukraine, Transylvania electricity voltage in usa, and Japan, interaction with a disposed placenta is thought to influence the parents’ future fertility.

Several cultures believe the placenta to be or have been alive, often a relative of the baby. Nepalese think of the placenta as a friend of the baby; Malaysian Orang Asli regard it as the baby’s older sibling. [37] Native Hawaiians believe that the placenta is a part of the baby, and traditionally plant it with a tree that can then grow alongside the child. [33] Various cultures in Indonesia, such as Javanese, believe that the placenta has a spirit and needs to be buried outside the family house.

In some cultures, the placenta is eaten, a practice known as placentophagy. In some eastern cultures, such as China, the dried placenta ( ziheche 紫 河 車, literally online electricity bill payment purple river cart) is thought to be a healthful restorative and is sometimes used in preparations of traditional Chinese medicine and various health products. [39] The practice of human placentophagy has become a more recent trend in western cultures and is not without controversy; its practice being considered cannibalism is debated.