What are the stages of follicle maturation in the ovary?
Preantral follicular development can be divided into three stages: activation of primordial follicles, the primary to secondary follicle transition, and the development of secondary follicles to the periantral stage.
What causes ovarian follicle maturation?
At sexual maturity, two hormones, produced by the pituitary gland: follicle stimulating hormone (FSH) and lutenising hormone (LH) cause these primordial follicles to develop. In each ovarian cycle, about 20 primordial follicles are activated to begin maturation.
What is ovarian follicular maturation?
Follicular maturation and development is a complex process of interrelated intra- and extraovarian events that ultimately lead to ovulation of a mature oocyte and transformation of the ruptured follicle into a corpus luteum.
What stimulates maturation of ovarian follicles?
Follicle-Stimulating Hormone As its name implies, FSH stimulates the maturation of ovarian follicles. Administration of FSH to humans and animals induces “superovulation”, or development of more than the usual number of mature follicles and hence, an increased number of mature gametes.
What is mature follicle?
A follicle is a small sac of fluid in the ovaries that contains a developing egg. Each month, one follicle is selected and goes on to maturity. When this follicle has matured and grown to the right size the follicle ruptures and releases the egg, which is now ready to be fertilised.
How a follicle matures in the female reproductive system?
As the follicular phase progresses, one follicle in one ovary becomes dominant and continues to mature. This dominant follicle suppresses all of the other follicles in the group. As a result, they stop growing and die. The dominant follicle continues to produce estrogen.
What changes occur in the follicle as a result of maturation?
The follicles undergo a growth phase and their diameter increases. This growth is strictly parallel in term of duration to that of the oocyte. Appears at puberty, so the follicle increases in size and the oocyte is surrounded by a regular layer of follicle cells.
Where does follicle maturation occur?
The hypothalamus secretes GnRH in a pulsatile fashion, which triggers FSH and LH release from the anterior pituitary. These, in turn, act on the granulosa and theca cells in the ovary to stimulate follicle maturation and trigger ovulation.
How follicles evolve in the ovaries before ovulation?
But before that occurs, during your period, your ovaries are preparing the next egg for ovulation. Between five and six follicles will start to grow in your ovary. The hormone FSH—follicle stimulating hormone—is produced and released by the pituitary gland. It’s this hormone that triggers the follicles to mature.
When does the ovarian follicle reach its mature stage?
An ovarian follicle progresses through several distinct phases before it releases its ovum. During the first five months of development, a finite number of primordial follicles form in the fetal ovary. The late primary follicle stage is reached when the follicular cells proliferate into a stratified epithelium known as the zona granulosa.
Where are the primordial follicles located in the ovary?
An ovarian follicle progresses through several distinct phases before it releases its ovum. During the first five months of development, a finite number of primordial follicles form in the fetal ovary. These follicles consist of oocytes surrounded by a single layer of squamous follicular cells.
When do ovarian follicles disintegrate during fertility treatment?
The follicles that do not release a mature egg disintegrate, a process known as atresia that can happen at any stage of follicular development. About 99% of ovarian follicles will disintegrate and never become mature enough to release an egg. 1 Follicle growth and development are tracked during fertility treatments.
Are there any options for in vitro follicle maturation?
Ovarian tissue cryopreservation and in vitro follicle maturation are currently areas of high research interest, as they may be the only option for some patients with cancer to preserve their fertility.
