Fertilisation. Animation showing a sperm (spermatozoon) penetrating a human egg (round). Women usually release one egg (ovum) per month, whereas men release millions of sperm in each ejaculation. Only one of these sperm can penetrate the egg's thick outer layer (zona pellucida) and fertilise it. As the sperm fuses with the egg it activates the release of calcium ions from the endoplasmic reticulum in the egg's cytoplasm. Here, this release is visualised by the change of colour over the egg's surface. This calcium ion wave modifies the egg surface so that if forms a barrier to other sperm. | |
Licence : | Droits gérés |
Crédit : | Science Photo Library / Biocosmos / Francis Leroy & Valentin Legrand |
Model Release : | Non requis |
Durée : | 14 Secondes |
Aspect ratio : | 16/9 |
Restrictions : | - |