TYPES OF PLACENTA BASED ON THE SOURCE OF VASCULAR SUPPLY. • From the Vitelline circulation of the yolk sac or Allantoic circulation. provided by the allantois : 1.
Chorio-vitelline/ Yolk-sac placenta
– Highly vascular yolk sac fuses with.
What are different types of placenta?
Mammalian placentas are classified into two types according to the fetal membrane including to chorion,
yolk sac placenta (choriovitelline placenta) and chorioallantoic placenta
.
What is placenta different types of placenta?
| Type of Placenta Common Examples | Diffuse, epitheliochorial Horses and pigs | Cotyledonary, epitheliochorial Ruminants (cattle, sheep, goats, deer) | Zonary, endotheliochorial Carnivores (dog, cat, ferret) | Discoid, hemochorial Humans, apes, monkeys and rodents |
|---|
What is the type of placenta in human?
Structure. Placental mammals, such as humans, have
a chorioallantoic placenta
that forms from the chorion and allantois.
How many types of placenta are there during pregnancy?
There are
three types
of this condition. The type is determined by how deeply the placenta is attached to the uterus. Placenta accreta: The placenta firmly attaches to the wall of the uterus. It does not pass through the wall of the uterus or impact the muscles of the uterus.
What are the abnormalities of placenta?
These placental disorders are called
placenta previa, placenta accreta, placenta increta or placenta percreta
. Placental disorders are usually diagnosed by ultrasound in the second trimester (about 18 to 20 weeks into a pregnancy). Placenta previa occurs when the placenta covers some or all of the cervix.
What are the 3 layers of the placenta?
A) Human placenta layers:
amnion, chorion, and decidua
. Amniotic layer is composed of a single-celled epithelial layer and a deeper mesodermal layer. Chorionic layer is composed of a mesodermal layer and a trophoblast layer.
What is placenta and its function?
The placenta is an organ that develops in your uterus during pregnancy. This structure
provides oxygen and nutrients to your growing baby and removes waste products from your baby’s blood
. The placenta attaches to the wall of your uterus, and your baby’s umbilical cord arises from it.
What is a mature placenta?
The mature placenta is
disklike in shape, 3 cm thick, and about 20 cm in diameter
. A typical placenta weighs about 500 g. The fetal side of the placenta is shiny because of the apposed amniotic membrane. The maternal side of the placenta is dull and is subdivided into as many as 35 lobes.
What is the chorionic placenta?
The fetal part of the placenta is known as the chorion. The maternal component of the placenta is known as the
decidua basalis
. Oxygen and nutrients in the maternal blood in the intervillous spaces diffuse through the walls of the villi and enter the fetal capillaries.
How many cotyledons does a placenta have?
Maternal surface: dull greyish red in colour and is divided into
15-20 cotyledons
. Each cotyledon is formed of the branches of one main villus stem covered by decidua basalis.
Why human placenta is called as Allanto chorionic placenta?
(i) Definition: Placenta is defined as a temporary intimate mechanical and physiological connection between foetal and maternal tissues for the nutrition, respiration and excretion of the foetus. (ii) Structure:
Human placenta consist of chorion only
. Hence, it is called a chorionic placenta. Allantois remains small.
What happens if placenta is posterior?
If the placenta attaches to the back of the uterus
, it’s known as a posterior placenta. If it attaches to the front of the uterus, it’s called an anterior placenta. Both types are common.
Does posterior placenta mean boy or girl?
Posterior placenta linked to gender of fetus: There
is no scientific evidence
that proves that a posterior placenta means a boy or a girl. The same holds true for a fundal posterior placenta and an anterior placenta.
Which position of placenta is best for normal delivery?
The upper (or fundal) portion of the uterine back wall
is one of the best locations for the fetus to be in. It allows them to move into the anterior position just before birth. Furthermore, a posterior placenta does not affect or interfere with the growth and development of the fetus.
What is a Succenturiate placenta?
The succenturiate placenta is
a condition in which one or more accessory lobes develop in the membranes apart from the main placental body to which vessels of fetal origin usually connect them
. It is a smaller variant of a bilobed placenta.
