Is it better for the follicle to be on the left or the right?

Nowadays, many women need to undergo a systematic examination during pregnancy. This systematic examination not only tests the health of their endocrine, hormones, progesterone and follicles. Too many or too few follicles are not good, and may cause some complications. Some people are more concerned about whether the follicles are better on the right or left. Let's take a look at what kind of follicles are the dominant follicles.

Dominant follicle

The primordial follicle is composed of a large primary oocyte and a single layer of flat follicle cells surrounding it. There are about 1 million primordial follicles in the ovarian cortex of newborns, but most of them cannot reach the mature stage. They atrophy and degenerate one after another to form atretic follicles. The development of primordial follicles into growing follicles does not require hormonal regulation.

What are the criteria for a dominant follicle? The primary oocyte of a growing follicle is enlarged, and significant RNA and protein synthesis occurs within the cell. After the follicle cells become cubic or columnar, they rapidly proliferate into multiple layers.

A thick membrane is formed between the oocyte and the follicle cells, called the zona pellucida, which is a gelatinous glycoprotein complex. Under the electron microscope, the microvilli on the surface of the oocyte and the protrusions of the follicular cells can be seen extending into the zona pellucida, which is beneficial for the follicular cells to transport nutrients to the oocyte.

The zona pellucida plays an important role in identifying sperm species and preventing polyspermy. The follicular cells continue to proliferate, and the small cavities between the follicular cells gradually fuse into a larger follicular cavity, which is filled with follicular fluid containing hyaluronic acid, estrogen and nutrients.

The criteria for the dominant follicle: As the follicular fluid continues to increase and the follicular cavity continues to expand, the oocyte and some of the surrounding follicular cells are squeezed to one side of the follicle and protrude into the follicular cavity, which is called the cumulus ovum. The remaining follicle cells that make up the egg wall are densely arranged into several layers, called the granulosa layer.

A layer of columnar follicle cells close to the zona pellucida, arranged radially, is called the corona radiata. The connective tissue around the follicle forms two layers of follicle membranes. The inner layer has more cells and is rich in capillaries. The inner layer cells and follicular cells work together to secrete estrogen; the outer layer has more fibers. Starting from puberty, several to dozens of follicles grow and develop in each cycle, but only one follicle matures, occasionally two, and the rest are atretic.

ovulation

The enlarged follicle is close to the ovarian cortex, and there is only a layer of epithelial cells separating the follicular wall and the abdominal cavity. The pressure inside the follicular wall does not increase, but the blood supply increases. The follicular wall becomes edematous and thinner. Fibrinolysozyme activates collagenase, and prostaglandins act on the basement membrane of the follicular wall to digest the protein in the follicular wall and contract the surrounding smooth muscles. The epithelial cells undergo necrosis, releasing hydrolases and proteases. The ovulation pore is formed, the follicle ruptures, and the contents are discharged. The oocyte is connected to the cumulus cells and granulosa cells by a small bundle. After the bundle breaks, the cumulus-ovarian complex is discharged.

About 14 days after ovulation, the periodic bleeding accompanied by the shedding of the endometrium is menstruation.