How do follicles form, develop and degenerate?

Follicles are enclosures containing eggs on the inside, each month the woman usually has an ovulation period but before the ovulation, the follicles will undergo a period of enlarged growth, thin cystic corcles and then disappear so that the inner egg is released.

Follicles are enclosures containing eggs on the inside. During the fetal period, by the week of 18-22, the ovaries in girls produced about 7 million primary egg cells. However, at the birth of the ovarian shell area of girls there are only 1 million -2 million primary egg cells left, all of which are in the pre-stage of reducing feces I. Each primary egg cell is surrounded by a layer of sscaly apothmous cell, which forms primitive cysts.

By puberty, the ovaries have less than 300,000 primary egg cells, and begin to function on a monthly cycle. In each cycle, only one follicle matures and sheds, therefore the entire period of reproduction activity in females uses only a maximum of about 400 follicles. During menopause, the ovaries have only approximately 1,000 primary egg cells left.

After puberty, primitive follicles begin to undergo a series of important changes, both in hissular structure and in the function of hormone secretion. The m maturity process of an follicle lasts about more than 120 days. This is the time of development from a primitive cyst that in turn goes through stages: the primary cyst, the second cyst, the cyst with cavities, and finally becomes a pre-ovulation cyst. This phenomenon occurs on the head pillow constantly, that is, at any time in the ovaries there are cysts that are at different stages of development.

The beginning of the m mature cycle of follicles is the recruitment of a primitive group of cysts. About 10 days before the end of the medification cycle, most of the initially recruited cysts have entered the degenerative process. The few remaining cysts that are at the stage of the second cyst will enter the menstrual cycle, and compete with each other until only one follicle survives. This cyst develops into a pre-ovulation cyst or superior cyst, which then breaks off and releases the second egg cell into the proboscis, the rest of the cyst then distinguishes it from the crown.

Unlike long-term spermation in men, the medation of the follicles in females ends when ovarian reserve is depleted, the remaining number of cysts is insufficient to respond to endo noisy signals from the ant long-term sedate gland, signaling the on-the-beginning of menopause.

The follicles in a female have 2 different fates: most of the follicles will degenerate during recruitment; a small number of cysts will mature, undergo ovulation, and enter the menstrual cycle every month.

Degeneration is a frequent process in the ovaries, in which the inmed adult cysts will be digested under the controlled action of subsymable and endometropic substances. Programmable death of granular cells is considered the fundamental mechanism in cystic degeneration, involving the functioning of 5 different signaling systems, including: TNF (tumor necrosis factor alpha), Fas ligand, TRAIL (TNF-related apoptosis-inducing ligand), APO-3 ligand ligand, PFG-5 ligand. In contrast, the hormone FSH from the sysague plays a role in inhibiting this phenomenon.

Thus, the planned death during the recruitment of follicles periodically at the age of reproduction has helped explain why each ovary possesses up to 300,000 primitive follicles at the time after puberty, but when menopause, the ovarian reserve is only approximately 1,000 follicles left.