Search results
Results from the WOW.Com Content Network
An antral or secondary follicle, also known as Graafian follicle and tertiary follicle, is an ovarian follicle during a certain latter stage of folliculogenesis. Definitions differ in where the shift into an antral follicle occurs in the staging of folliculogenesis, with some stating that it occurs when entering the secondary stage, [ 1 ] and ...
An ovarian follicle is a roughly spheroid cellular aggregation set found in the ovaries. It secretes hormones that influence stages of the menstrual cycle . At the time of puberty , women have approximately 200,000 to 300,000 follicles, [ 1 ] [ 2 ] each with the potential to release an egg cell (ovum) at ovulation for fertilization . [ 3 ]
In addition, follicles that have formed an antrum are called antral follicles or Graafian follicles. Definitions differ in where this shift occurs in the staging given above, with some stating that it occurs when entering the secondary stage, [ 2 ] and others stating that it occurs when entering the tertiary stage.
Section of vesicular ovarian follicle of a cat. X 50. Membrana granulosa labeled at upper left. In the development of the urinary and reproductive organs, the oogonia become invaginated in the gonadal ridge. The embryological origin of granulosa cells remains controversial.
The follicular antrum is the portion of an ovarian follicle filled with follicular fluid. Appearance of the follicular antrum during follicular maturation is the first sign that a follicle has reached the next stage of maturation. It has changed from a primary follicle to a secondary follicle.
The rise in FSH levels recruits five to seven tertiary-stage ovarian follicles (this stage follicle is also known as a Graafian follicle or antral follicle) for entry into the menstrual cycle. These follicles, that have been growing for the better part of a year in a process known as folliculogenesis, compete with each other for dominance. [5]
The theca folliculi comprise a layer of the ovarian follicles. They appear as the follicles become secondary follicles. The theca are divided into two layers, the theca interna and the theca externa. [1] Theca cells are a group of endocrine cells in the ovary made up of connective tissue surrounding the follicle.
As the follicle matures, the area between the follicle and the ovarian surface begins to thin and weaken under the influence of the luteinizing hormone and local cytokines. At ovulation the stigma ruptures and the secondary oocyte is released along with surrounding granulosa cells, from the region of the cumulus oophorus, and follicular fluid.