Graafian follicle being a complex structure in mammals produces a hormone called estrogen, which one of the following structures produce estrogen?
Tertiary follicle grows further into the Graafian follicle with a large follicular cavity or antrum that is filled by a liquid called liquor folliculi.
The granulosa cells of the growing follicle produce estradiol in the follicular phase of the ovarian cycle and secrete estrogens in response to FSH.
Theca externa is the outermost layer of the folliculi which is the derivation of connective tissue that contributes structural support to the growing follicle.
Zona pellucida is the thick transparent layer that surrounds an ovum before implantation (zygote gets attached to the uterine wall). Zona pellucida triggers the sperm head to release acrosome.
Corona radiata is the innermost layer of the ovary which is present next to zona pellucida that supplies important proteins to the cell.