Sample embryology images from different times in development.
(for image details see the linked website)
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.
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.
After implantation the developing cells release a hormone to support the pregnancy. Pregnancy tests detect this hormone in the mother's urine.
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.
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.
There are More Sample Images.
Embryology website sample movies (for movie sources and descriptions see website).
The first 8 weeks of human embryonic development.
The events of follicle development and ovulation.
The process of ovulation from the ovary.
The events of egg fertilization.
Egg fertilization in the petri dish.
The first cell divisions of the 2 cell embryo.
Overview of first week of human development.
The process of conceptus implantation.
Overview of week 2 of human development.
Mesoderm spreading in the trilaminar embryo.
Growth of the neural plate (blue).
Development of the neural tube.
Growth of the amniotic cavity (blue).
The above weblog links to recent articles and news related to embryology.
Links to the UNSW Embryology website Glossary list (no current mobile version).Embryo Website
Search UNSW Embryology site
PubMed research publication database
Online Mendelian Inheritence in Man (OMIM) catalog of human genes and genetic disorders
PubMed collection of biomedical books
Entrez cross search all biomedical databases
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.
Links to online and PDF versions of embryology undergraduate lecture slides. Files may be up to 5 Mb in size and are 4 slides/page.
Tests carried out before birth
(invasive or non-invasive)
Tests carriend out after birth
(genetic and physiological)
A test of how a large catalogue of images can be organised to mobile browse.
Extensive Embryology education resource.
What's being published in embryology?
Links to undergraduate Embryology class notes.
Cell Biology education resource.
Cell Biology Laboratory homepage.
The following sites are under development for 2009.
Embryology undergraduate interactive education resource.
Cell Biology undergraduate interactive education resource.