The diagram of placenta shows that it is made up of fetal and maternal components. The placenta diagram with labels shows the umbilical arteries and veins for gas and nutrition exchange in the umbilical cord, which joins the fetus to the placenta. The placenta diagram in class 10 and class 12 textbooks shows its structure and is also asked in examinations.
The labeled diagram of the placenta is given below:
Placenta Diagram With Labels
Table of Content
What is Placenta?
The placenta, is a temporary organ that forms during pregnancy. Placenta diagram shows how it acts as a connection between the growing fetus and the mother. Placenta helps in the fetus’s immunological defence, hormone synthesis, waste removal, and nutrition and gas exchange. Maternal and fetal tissues combine to produce the placenta, which is joined to the uterine wall and connects to the fetus by the umbilical cord. It is essential for maintaining the fetus’s growth and development throughout pregnancy.
Structure of Placenta
The labelled diagram of placenta shows the following structure:
- Maternal Side: The uterine lining, called the decidua basalis, attaches to the placenta and enables maternal-fetal exchange via spiral arteries.
- Maternal Decidua: The placenta’s basal plate forms from altered endometrial tissue, helping in placental adhesion.
- Fetal Side: Chorionic villi, projecting from the fetal chorion, compose the placenta’s fetal side, facilitating gas and nutrient exchange between fetal and maternal circulations.
- Fetal Chorionic Plate: Formed by chorionic villi, the fetal chorionic plate comprises decidua embedded within the villi.
- Villous Tree: The branching chorionic villi structure includes terminal, intermediate, and stem villi encircling fetal blood arteries.
- Intervillous Space: This space, filled with maternal blood, allows for mother-fetal communication via chorionic villi.
- Umbilical Cord: Comprising two umbilical arteries and one vein, it transports fetal blood to and from the placenta for nutrient and gas exchange.
- Amniotic Cavity: Surrounding the fetal side, the amniotic cavity contains amniotic fluid, protecting and cushioning the fetus.
- Placental Lobules: These functional units, divided by septa, contain clusters of chorionic villi for maternal-fetal communication.
- Maternal Circulation: Maternal blood enters the placenta via spiral arteries, filtering waste and supplying oxygen and nutrients before leaving through veins.
- Fetal Circulation: Fetal blood travels to the placenta through umbilical arteries. It exchanges nutrients and gases in placental lobules, and returns to the fetus via the umbilical vein.
Types of Placenta
Placenta comes in different types depending on how they attach to the uterine wall. The main types include:
- Diffuse Placenta: In this type, the chorionic villi are spread out uniformly over the entire surface of the chorionic sac.
- Cotyledonary Placenta: This type features several discrete, button-like areas of attachment known as cotyledons on the maternal side and corresponding caruncles on the fetal side.
- Zonary Placenta: Found in carnivores like dogs and cats, this type forms a belt-like band around the fetal membranes.
- Discoid Placenta: Seen in humans and primates, it is disc-shaped and attaches directly to the uterine wall at a single point.
Placenta Diagram and Function
Placenta diagram and function serve as fundamental topics in biology studies. The diagram of placenta shows its detailed structure which makes studying the functions easier. Some of the functions of placenta are given below:
- Nutrient and Oxygen Supply: The placenta supplies nutrients including glucose, amino acids, fatty acids and oxygen to the foetus, functioning as a conduit between the mother’s bloodstream and the growing baby.
- Waste Elimination: The placenta removes waste products generated by the fetus, including urea, and transports them back into the mother’s bloodstream for excretion.
- Hormone Production: Hormones necessary for sustaining pregnancy and promoting fetal growth are produced by the placenta.
- Immune Protection: The placenta transfers nutrients and waste between mother and fetus. It also protects the developing embryo by blocking harmful substances present in mother’s womb like infections and toxins from reaching it.
- Endocrine Function: The placenta produces hormones and contributes to the endocrine system. It secretes hormones like relaxin and estrogen, which maintains and helps in the process of pregnancy and child birth.
Also Read: Difference Between Estrogen And Progesterone
Conclusion – Diagram of Placenta
The placenta is a temporary organ which is formed during pregnancy. Histologically, it is made up of the fetal chorionic plate with chorionic villi, the maternal decidua that forms the basal plate, and the intervillous gap that allows for exchange. The diagram of placenta shows its detailed structure which helps gain an insight into its anatomy and functions. Placenta diagram NCERT provides a detailed illustration of the organ’s anatomy and function.
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FAQs on Placenta Diagram
What is the Structure of Placenta?
A mature placenta weighs 500-600 grams, divided into 15-28 cotyledons. Each cotyledon has stem villi branching into 3-5 intermediate villi, which further divide into 10-12 terminal villi for maternal-fetal exchange.
What are the 4 Types of Placenta?
Posterior placenta: The placenta grows on the back wall of your uterus. Anterior placenta: The placenta grows on the front wall of your uterus closest to your abdomen. Fundal placenta: The placenta grows at the top of your uterus. Lateral placenta: The placenta grows on the right or left wall of your uterus.
What is a Placenta?
The placenta is a temporary organ formed during pregnancy, connecting the fetus to the uterine wall, facilitating nutrient and gas exchange between the mother and the developing baby
What is Placenta Function?
The placenta functions as a conduit for nutrient and gas exchange between the mother and developing fetus, while also providing hormonal support and immune protection.
Where is Placenta Located?
The placenta is located within the uterus, attached to the uterine wall, usually near the top or sides of the uterus.
How is Placenta Formed?
The placenta is formed through the fusion of maternal and fetal tissues during early pregnancy, originating from the trophoblast cells of the developing embryo and the uterine lining.
Where can I Find the Diagram of Placenta Class 10?
You can find the labelled diagram at the top of this article.
What is the Functional Part of the Placenta?
The functional part of the placenta is the chorionic villi, which exchange nutrients and oxygen between the mother and the fetus.
What is the Storage Function of the Placenta?
The placenta stores glycogen, iron, and calcium, essential for fetal development and growth.