iPhone Embryo

Sample embryology images from different times in development.

(for image details see the linked website)

Week 1

The human zygote, the first cell formed following fertilization. In the middle, the 2 pronuclei (one maternal and paternal) containing the parents genetic material. These will fuse to form the new genetic mix of the child.

Zygote image | More Images

Embryo Website | Week 1 Notes

Week 2

The blastocyst, the cell mass formed by cell divisions in the first two weeks following fertilization. This image, at the end of the first week, shows the blastocyst (right) "hatching" out of the surrounding protective shell, the zona pellucida (left).

A summary of the first 2 weeks of human development. The image shows from ovulation to fertilization and through to implantation during the second week.

First 2 weeks image | More Images

Embryo Website | Week 2 Notes icon

After implantation the developing cells release a hormone to support the pregnancy. Pregnancy tests detect this hormone in the mother's urine.

Pregnancy Test image | More Images

Embryo Website | Week 2 Notes

Week 3

The embryo in the third week is initially a flat disc of cells. This embryo is 15 - 17 days old and 0.4 mm in diameter, the head will develop at the top and the placenta at the bottom.

Week 3 image | More Images

Embryo Website | Week 3 Notes | Stage 7 Embryo

Week 4

This embryo in the fourth week (about 21 days) is now folded and 2 mm in length. The head will develop at the top and the placenta at the bottom. The bulge visible on the left is the early heart, the first organ to form. The valley or groove in the middle will form the early spinal cord and brain.

Week 4 image | More Images

Embryo Website |

Stage 10 Embryo | Embryo Stages System Notes |

There are More Sample Images.

Embryology website sample movies (for movie sources and descriptions see website).

Stages

The first 8 weeks of human embryonic development.

Week 1

Follicle

The events of follicle development and ovulation.

Ovulation

The process of ovulation from the ovary.

Fertilization

The events of egg fertilization.

IVF

Egg fertilization in the petri dish.

Early Division

The first cell divisions of the 2 cell embryo.

Week 1

Overview of first week of human development.

Week 2

Implantation

The process of conceptus implantation.

Week 2

Overview of week 2 of human development.

Week 3

Mesoderm

Mesoderm spreading in the trilaminar embryo.

Neural Plate

Growth of the neural plate (blue).

Neural Tube

Development of the neural tube.

Amniotic Cavity

Growth of the amniotic cavity (blue).

More Movies

Embryo Website

UNSW Embryo

Search UNSW Embryology site

PubMed

PubMed research publication database

OMIM

Online Mendelian Inheritence in Man (OMIM) catalog of human genes and genetic disorders

Bookshelf

PubMed collection of biomedical books

Entrez

Entrez cross search all biomedical databases

UNSW Embryology

Link to UNSW Embryology website search page

Dr Mark Hill is a senior lecturer in the School of Medical Sciences, The University of New South Wales, Sydney Australia.

Email the Author

I have been an educator to both Medical and Science students in Embryology and Cell Biology at the University level for the last 13 years. I am interested in how new technologies can be used to best present, and help aid the understanding of, complex developmental processes.

My laboratory research interests are looking at the relationship between cell shape and function, in particular in neurological development and disease.