Embryo Model

Quick Answer: The embryo model is an enlarged three-dimensional model of an early embryo, normally a human embryo in the weeks when its organs first form. Biology, nursing and medical students use an embryo model to identify features such as the pharyngeal arches, limb buds, somites and the bulge of the developing heart.

The Embryonic Period in Three Dimensions

The weeks from about the third to the eighth after fertilisation are the period of organ formation, when almost every body system begins. The embryo is then only millimetres long and curled into a C shape, so an enlarged model is the practical way to see its surface. Along the back runs a row of paired blocks called somites, which will form the vertebrae, back muscles and deeper layer of the skin of the back. Beneath the head sit the pharyngeal arches, ridges that give rise to the jaws, middle ear bones and structures of the face and neck.

The heart forms early and begins to beat around 22 days after fertilisation, so on most embryo models it appears as a large bulge below the head. Arm buds appear as small paddles near the end of the fourth week and leg buds a few days later, while the eyes and ear pits become visible on the head. Tracing these features on a model links the textbook timeline to a shape.

The title does not state which age the model represents, whether it is one model or several, or its scale. For a sequence of stages, the human embryo development set shows development over time.

Specifications

Applications

• Embryology lectures and practicals in medical, nursing and biology courses
• Explaining the origin of conditions that arise in the embryonic period, such as neural tube defects
• Linking the pharyngeal arches to the adult face and neck in anatomy teaching
• Senior secondary and college biology lessons on human development

Care & Handling

• Handle the embryo model by its base; the curled body and limb buds are thin in places.
• Dust it with a soft brush, especially along the row of somites where grooves collect dirt.
• Store it out of direct sun so the colour coding of the tissues stays clear.

Why Choose LabEquip

Embryology is hard to teach from flat diagrams because the embryo folds in three dimensions, which is why medical and nursing colleges buy models like this. The model sits in LabEquip’s biology lab products; ask about its stage through the contact page.

Frequently Asked Questions

What is the difference between an embryo and a fetus?

In humans the developing baby is called an embryo from fertilisation to the end of the eighth week, by which time the main organs have formed. From the ninth week until birth it is called a fetus, and development is mainly growth and maturation.

What are somites?

They are paired blocks of tissue that form in a row on either side of the neural tube. Each later gives rise to part of a vertebra, muscles of the back and body wall and the deeper skin layer of the back. Counting somites is used to stage young embryos.

What are pharyngeal arches?

They are a series of ridges on the side of the embryo’s future neck. Each contains cartilage, muscle, a nerve and an artery, and together they form the jaws, the middle ear bones, parts of the face and neck structures such as the larynx.

When does the embryonic heart start beating?

At about 22 days after fertilisation, near the start of the fourth week. Blood begins to circulate soon afterwards, making the heart one of the first organs to work.

Why is the embryonic period important in pregnancy care?

While organs are forming, the embryo is most sensitive to harmful exposures such as some medicines, alcohol and infections. This is also why folic acid is advised before conception and in early pregnancy, to lower the risk of neural tube defects.

What is the neural tube?

It is the tube that forms along the embryo’s back when the neural plate folds and closes during the fourth week. It becomes the brain and spinal cord. If it does not close fully, defects such as spina bifida result.

Last Updated: September 2026