Now in our 13th year of bringing you beautiful imagery from biomedical science every day

Search the archive of over 4000 images

All about Eggs
08 April 2012

All about Eggs

While many of us tuck into our chocolate eggs today, there are simultaneously tens of thousands of women ovulating across the world. Human eggs are, unlike their male counterparts, rather large cells. Produced by fluid-filled sacs on the side of the ovary, they emerge surrounded by a jelly-like substance containing nutritive cells. So-called follicle cells (coloured pink in this electron micrograph) send out long projections that penetrate through the tough outer coating (the zona pellucida) into the egg itself (here coloured yellow) to nourish it through to maturity. As the egg progresses along the Fallopian tube after ovulation, the cloud of nutritive cells gradually falls away. The human egg can be magnified up to 500,000 times using a scanning electron microscope. In real life, it is roughly the size of a full stop.

Written by Brona McVittie

  • Yorgos Nikas
  • Originally published under Creative Commons (CC-BY-NC-ND); Courtesy of Wellcome Images

Search The Archive

Submit An Image

Follow on Tumblr

Follow on Instagram

What is BPoD?

BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

Read More

BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.