Ovulation takes place in the tissues of the ovary
These images are the first time the event has been captured in clear detail
The egg is shown emerging from the follicle on the ovary
After release, the egg travels down the Fallopian tube where it can be fertilised
A human egg has been filmed in close-up emerging from the ovary for the first time, captured by chance during a routine operation.
Fertile women release one or more eggs every month, but until now, only animal ovulation has been recorded in detail.
Gynaecologist Dr Jacques Donnez spotted it in progress during a hysterectomy.
The pictures, published in New Scientist magazine, were described as "fascinating" by a UK fertility specialist.
Human eggs are produced by follicles, fluid-filled sacs on the side of the ovary, which, around the time of ovulation, produce a reddish protrusion seen in the pictures.
The egg comes from the end of this, surrounded by a jelly-like substance containing cells.
The egg itself is only the size of a full-stop, and the whole ovary, which contains many immature eggs, just a couple of inches long.
They belonged to a 45-year-old Belgian woman, and Dr Donnez, from the Catholic University of Louvain, told New Scientist that the pictures would help scientists understand the mechanisms involved.
He said that some theories had suggested an "explosive" release for the egg, but the ovulation he witnessed took 15 minutes to complete.
Professor Alan McNeilly, from the Medical Research Council's Human Reproduction Unit in Edinburgh, said that this fitted with his own research into the ovulation process.
He said: "It really is a fascinating insight into ovulation, and to see it in real life is an incredibly rare occurrence.
"It really is a pivotal moment in the whole process, the beginnings of life in a way."