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Definition of Placenta
1. Concept of Placenta
The placenta is that body that acts as intermediary between the mother and the fetus while lasts the process of gestation. It is present in almost all mammals, and in humans (pregnant women) dealing especially with the main needs of the fetus while it is in the belly, breathing, nutrition and excretion.The composition of the placenta is the result of the same cells that come from the sperm and egg that originated the fetus and has two components, a fetal portion or smooth Chorion and a maternal or decidua corionic portion. Meanwhile, the function of these two components is put into relationship of blood equal to the corresponding to the mother and the fetus.
Human placenta will begin to form in the second week after fertilization, while both, it will acquire its form and final structure, round disc-shaped, approximately when the mother enter in the third month of pregnancy, though, is viable that the same suffer some minor until the end of the pregnancy.
The baby is attached to the placenta through the umbilical cord, which is a vascular tube with waste and deoxygenated blood from the baby until the placenta to have Exchange becomes effective with the mother and then take back to the baby with oxygen and nutrients. The Exchange is quite selective since only cease through well-defined substances unless the baby's blood to mix with the mother's.
One of its main functions, as we said, is the uninterruptible power supply of the fetus throughout pregnancy, the baby will draw blood from the mother all those elements that are required for their development (oxygen, proteins, glucose, fats, among others). It will also deal with the Elimination of all those elements that are not necessary for the baby; as the organs of this are still very immature placenta will deal with mediating in this evacuation so they arrive to the mother and she be expelled. And the placenta also holds the function of producing those hormones that are essential to ensure the development of the fetus, such is the case of human chorionic gonadotropin.
On the other hand, the placenta acts as Shield impenetrable when it comes to defending the fetus of aggressive for their correct growth substances such as: parasites, viruses and bacteria.
It should be noted, that it is quite common that some women with placental dysfunction as a result of suffering from conditions such as diabetes mellitus, chronic hypertension, preeclampsia, chronic kidney disease, among others, therefore, must be monitored closely by their doctors to prevent such issue to put at risk the life of the baby.
2. Definition of Placenta
Placenta - latin cake flat referring to their appearance in humans - is an ephemeral organ present in placental mammals and that closely related to the baby with her mother, breathing, nutrition and excretion of the fetus during its development needs. The placenta develops from the same cells from the sperm and egg that gave the fetus development and has two components, a fetal portion, the thick Chorion and a maternal or decidua basal portion.The human placenta is of type hemocorial (or discoid), which means that the fetal tissue penetrates the endometrium to the point of being in contact with the maternal blood. This type of placenta all primates and rodents have it. However, among the mammals there are other types of placenta: Besides, the old concept of the placenta barrier of harmful substances has been widely surpassed by the idea that she is a sieve that allows the transport of substances both profitable, as the undesirable for the fetus.The placental membrane which separates the maternal and fetal circulation is made up of four layers; After 20 weeks, it reduces to three. (Moore and Persaud, 1993)
• Endoteliocorial: in which the Chorion penetrates in the endometrium, arriving to play mother vessels. It is characteristic of carnivores, as in cat, dog or Wolf.
• Sindesmocorial: in it the uterine mucosa epithelium remains intact, but the trophoblast comes into contact with the uterine tissue allowing the passage of nutrients. It exists in ruminants like sheep.
• Epiteliocorial: the Chorion touches lightly the maternal endometrium, but does not penetrate it, as it is the case in the sow.
The placenta type and thickness of the membrane or placental barrier are closely related to the passage of substances from the mother to the fetus, thus, there is a clear relationship, inversely proportional to the thickness of the placenta, in the transplacental passage of certain substances. This has been demonstrated, for example, studying the passage of sodium through the different types of placenta, and observed that the order in the variation of this ion (major minor) would be: hemocorial, endoteliocorial placenta, placenta sindesmocorial placenta epiteliocorial placenta. It should be noted, that in the studied ion (sodium), trade intensity increases almost regular throughout pregnancy, up to a maximum, shortly before giving birth. The final descent in these exchanges is attributed in the placenta hemocorial a deposit of fibrin on the surface in which the changes are made.
3 Meaning of Placenta
The placenta is the organ that emerges in the umbilical cord and allows the intermediation between the mother and her baby or breeding as the pregnancy develops. Thanks to the placenta, which attaches to the uterus, baby can be nurtured, breathe and expel waste.There are different types of placenta depending on the species. In the case of humans, the placenta qualifies as hemocorial since the fetus tissue becomes to establish contact with the blood of the mother.
As the pregnancy progresses, the placenta loses thickness so the exchanges are more intense. Once the birth occurs, this body must not comply with any other function, so the mother out. Some animals, and even human beings according to the culture, can eat the placenta removed once from the maternal body.
The intake of the placenta called placentophagy. There are physical reasons which justify such conduct: its components, can facilitate the secretion of breast milk and reduce the stress that is caused by childbirth, for example. A few years ago there was a stir when actor Tom Cruise said that the placenta from the mother of his daughter Suri, eat although he later denied it.
Referred to as placenta previa, on the other hand, a problem that can arise in pregnancy when this body adheres to the lower region of the uterus, what you can do to lock out is the cervix. Placenta previa, therefore, prevents the fetus out of the uterus by birth canal.
