Fetus with Viscera and Placenta

Quick Answer: The fetus with viscera and placenta is a model of a fetus with its internal organs (viscera) exposed, joined by the umbilical cord to a placenta. It is used in nursing, midwifery and medical teaching to show fetal anatomy and, above all, how fetal circulation differs from circulation after birth.

Fetal Circulation, Organ by Organ

The value of showing the viscera is that the fetal shunts can be traced. Oxygen-rich blood leaves the placenta in the single umbilical vein and reaches the liver, where much of it bypasses the liver tissue through the ductus venosus into the inferior vena cava. In the heart, blood passes from the right atrium to the left through the foramen ovale, and much of the blood pumped into the pulmonary trunk crosses to the aorta through the ductus arteriosus, because the fluid-filled lungs need little flow. Two umbilical arteries return blood to the placenta.

At birth these shunts close. The first breaths expand the lungs and lower resistance in the pulmonary vessels, pressure in the left atrium rises and pushes the flap of the foramen ovale shut, and the ductus arteriosus constricts over the following hours to days. The ductus venosus and the umbilical vessels later become ligaments. A model showing the heart, liver, lungs and cord together is a clear way to teach this change.

Viscera models also show fetal proportions: the liver is very large and fills much of the abdomen, and the head is big relative to the body. The gestational age represented, the scale and whether organs can be removed are not stated in the title; the related human placenta model shows the placental surfaces in more detail.

Care & Handling

• Support both the fetus and the placenta when lifting the model so the cord connection is not strained.
• Clean the exposed organs with a soft dry brush; damp cloths can lift paint from fine vessel detail.
• Store it flat in its box with any removable organs replaced.

Specifications

Applications

• Teaching fetal circulation and the changes at birth in midwifery and neonatal nursing
• Explaining congenital heart conditions linked to the shunts, such as patent ductus arteriosus
• Anatomy and embryology lectures on fetal organ proportions
• Antenatal education on how the baby is nourished before birth

Why Choose LabEquip

Midwifery schools and neonatal nursing programmes buy this kind of model because fetal circulation is difficult to grasp from a flat diagram alone. The model is part of LabEquip’s biology lab products; questions about the gestational age shown can go through the contact page.

Frequently Asked Questions

What are the three shunts in fetal circulation?

The ductus venosus, which carries blood from the umbilical vein past the liver tissue; the foramen ovale, an opening between the right and left atria; and the ductus arteriosus, which links the pulmonary trunk to the aorta. Together they divert blood away from the liver and the unused lungs.

Why does the umbilical vein carry oxygen-rich blood?

Vessels are named by the direction of flow, not by oxygen content. The umbilical vein carries blood towards the fetus, and that blood has just collected oxygen and nutrients in the placenta. The two umbilical arteries carry blood away from the fetus back to the placenta.

What happens to the foramen ovale after birth?

Once the baby breathes, pressure in the left atrium rises above that in the right and presses the flap closed. It usually seals permanently over the following months, leaving a shallow dip called the fossa ovalis. In some adults it never fully seals, which is called a patent foramen ovale.

What is a patent ductus arteriosus?

It is a ductus arteriosus that stays open after birth. It is more common in premature babies and lets blood flow from the aorta back into the lung circulation. Small ones may close on their own; larger ones may need medicine or a procedure.

Why is the fetal liver so large?

For much of pregnancy the liver is a major site of blood cell formation, and it is the first organ to receive oxygen-rich blood from the umbilical vein. It therefore makes up a much larger share of the body than in an adult, as the model shows.

Who uses a fetus with placenta model?

Midwifery and nursing schools, neonatal units that train staff and medical colleges teaching embryology and physiology. Biology teachers at advanced secondary level also use it for reproduction and circulation topics.

Last Updated: September 2026