Corona radiata (embryology)
|Corona radiata (embryology)|
|Human ovum examined fresh in the liquor folliculi. The zona pellucida is seen as a thick clear girdle surrounded by the cells of the corona radiata. |
The egg itself shows a central granular deutoplasmic area and a peripheral clear layer, and encloses the germinal vesicle, in which is seen the germinal spot.
|Histology of the preovulatory follicle|
|Gray's||subject #3 39|
The corona radiata surround an ovum or unfertilized egg cell, and consist of two or three strata (layers) of follicular cells. They are attached to the outer protective layer of the ovum, the zona pellucida, and their main purpose in many animals is to supply vital proteins to the cell. They appear at ovulation, but may disappear eventually after fertilization.