Human Placenta

Quick Answer: The human placenta model is an anatomical model of the placenta, the organ that links mother and fetus during pregnancy, usually shown with the umbilical cord attached. This placenta model is used in midwifery, nursing and biology teaching to show the maternal and fetal surfaces, the cord vessels and how the placenta exchanges substances.

Two Surfaces with Different Jobs

A full-term placenta is a disc about 20 cm across, and a teaching model typically shows both of its faces. The fetal surface is smooth and shiny, covered by the amnion, with the umbilical cord usually inserted near the centre and large vessels spreading from it. The maternal surface, which was attached to the uterine wall, is rough and dark red, divided by grooves into lobes called cotyledons. Inside, maternal blood fills the spaces around the villi while fetal blood stays within them, so the two circulations are close but separate.

Midwives inspect every placenta after birth, and the model is used to teach that check. The maternal surface is examined for missing cotyledons or ragged areas suggesting a piece has stayed in the uterus, which can cause bleeding or infection. The membranes are checked for completeness, and the cord for its insertion point and its three vessels. A single umbilical artery is noted because it is sometimes linked with other anomalies in the baby.

The placenta also acts as a hormone gland, producing human chorionic gonadotrophin, the hormone that pregnancy tests detect, along with progesterone and oestrogens that maintain the pregnancy. Whether this model is life size, shows a section through the villi or is mounted is not stated in the title. The fetus with viscera and placenta shows the placenta connected to the fetus.

Applications

• Teaching placental inspection after birth in midwifery training
• Biology lessons on exchange between maternal and fetal blood
• Explaining placental conditions such as placenta praevia and abruption
• Antenatal education on how the baby is nourished

Specifications

Care & Handling

• Store the human placenta model flat with the cord coiled loosely beside it rather than wrapped tight, so the cord does not kink or crack.
• Wipe with a soft damp cloth and dry; avoid scrubbing the textured maternal surface.
• Keep it out of sunlight to preserve the colour contrast between the two surfaces.

Why Choose LabEquip

Midwifery schools and nursing colleges use this model so students learn placental inspection before they see a real placenta on the delivery ward. LabEquip lists this model in its biology lab products; for questions about scale, use the contact page.

Frequently Asked Questions

What are cotyledons?

They are the lobes visible on the maternal surface of the placenta, separated by shallow grooves. Each contains branching villi bathed in maternal blood. After birth a midwife checks that all cotyledons are present, since a missing one may have stayed in the uterus.

How many vessels are in the umbilical cord?

Normally three: two arteries carrying blood from the fetus to the placenta and one vein carrying oxygen-rich blood back to the fetus. They are cushioned by a jelly-like tissue called Wharton’s jelly.

Do the mother’s and baby’s blood mix in the placenta?

Normally not. Maternal blood fills the spaces around the villi and fetal blood flows inside them, separated by a thin barrier. Oxygen, nutrients, antibodies and waste cross this barrier, but the two bloods stay in separate circulations.

What is placenta praevia?

It is a placenta that lies low in the uterus and partly or completely covers the cervix. It can cause painless bleeding in later pregnancy and may mean the baby has to be born by caesarean section.

What is placental abruption?

It is when the placenta separates from the uterine wall before the baby is born. It usually causes pain and bleeding and can be dangerous for mother and baby, so it needs urgent medical care.

Which hormones does the placenta make?

Mainly human chorionic gonadotrophin (hCG) in early pregnancy, which pregnancy tests detect, and progesterone and oestrogens, which maintain the uterine lining and prepare the breasts. It also makes human placental lactogen, which alters the mother’s metabolism.

Last Updated: September 2026