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Guilherme Mazui

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What is the Difference Between Chorion and Placenta?

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The chorion and placenta are both fetal membranes that play crucial roles in the development and support of the embryo during pregnancy. However, they have distinct structures and functions:

  • Chorion:
  • The chorion is the outermost membrane around the embryo in mammals, birds, and reptiles.
  • In mammals (except marsupials), the chorion develops a rich supply of blood vessels and forms an intimate association with the endometrium of the female's uterus.
  • The chorion and endometrium together form the placenta, which is the embryo's principal organ of respiration, nutrition, and excretion.
  • The chorion frondosum is the tissue surrounding the developing embryo and is eventually becomes the placental site.
  • Placenta:
  • The placenta is the embryo's principal organ of respiration, nutrition, and excretion, formed from the chorion and endometrium.
  • The placental membrane separates maternal blood from fetal blood, allowing for the exchange of nutrients and waste products.
  • Mammalian placentas are classified into two types according to the fetal membrane, including yolk sac placenta (choriovitelline placenta) and chorioallantoic placenta.
  • The chorioallantoic placenta is formed from the endometrium of the dam and the trophectoderm of the embryo, showing a variety of shapes between different animal species.

In summary, the chorion is a fetal membrane that forms an intimate association with the endometrium to create the placenta, which is the embryo's principal organ of respiration, nutrition, and excretion. The placenta is responsible for separating maternal and fetal blood, allowing for the exchange of nutrients and waste products.

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  • What is the Difference Between Chorion and Placenta?
  • Comparative Table: Chorion vs Placenta

    • Comparative Table: Chorion vs Placenta

    The chorion and placenta are two important parts of the fetal development that play crucial roles during pregnancy. Here is a table outlining the differences between them:

    Feature Chorion Placenta
    Definition The chorion is the fetal part of the placenta. The placenta is a discoid, oval-shaped organ that acts as a metabolic and endocrine organ located between the developing embryo and the endometrium.
    Composition The chorion is composed of four layers: cellular layer (fibroblast), reticular layer, basement membrane, and trophoblast. The placenta is derived from extra-embryonic tissues that develop rapidly and dynamically in the early stages of pregnancy.
    Formation Chorionic villi develop from the blastocyst during implantation. The placenta is formed during the development of the embryo.
    Function The chorion is part of the placenta, which is essential for establishing a pregnancy, allowing maternal physiological adaptation, embryonic immunological acceptance, support, and nutrition. The placenta provides the only fetomaternal connection and is essential for establishing a pregnancy, allowing maternal physiological adaptation, embryonic immunological acceptance, support, and nutrition.
    Hormones The placenta secretes important hormones such as hCG, hPL, estradiol, estriol, progesterone, alkaline phosphatase, diamine oxidase, and cysteine aminopeptidase. The placenta secretes important hormones such as hCG, hPL, estradiol, estriol, progesterone, alkaline phosphatase, diamine oxidase, and cysteine aminopeptidase.

    In summary, the chorion is the fetal part of the placenta, while the placenta is a larger organ that plays a vital role in fetal development and pregnancy. Both the chorion and placenta are essential for establishing and maintaining a healthy pregnancy.

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    Guilherme Mazui

    Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.