PROFESSORS P.M. MOTTA & S. MAKABE / SCIENCE PHOTO LIBRARY PROFESSORS P.M. MOTTA & S. MAKABE / SCIENCE PHOTO LIBRARY
Ovarian follicle. Coloured scanning electron micrograph of the interior of an ovarian follicle, showing the developing ovum before ovulation. This follicle is from a 43 year old woman. The ovum is surrounded by a protein layer known as the zona pellucida (yellow). This layer is secreted by the surrounding corona radiata (pink), a denser area of the granulosa cells which make up most of the follicle's lining. The follicle's inner cavity is filled with fluid containing proteins, sugars and hormones. Follicles mature in 10-14 days before bursting, releasing the ovum into a fallopian tube. Magnification: x200 at 6x7cm size.
Model release not required. Property release not required.