How does sperm enter the fallopian tube?

Sperm is the reproductive cell in a man's body. When sperm meets the egg, a fertilized egg may be formed, which can lead to pregnancy in women. Although most adults in life understand this principle, they still lack understanding of some specific situations. For example, few people know how sperm enters the female fallopian tube. So how does sperm enter the fallopian tube?

How does sperm enter the vagina?

During sexual intercourse between two sexes, after the semen is ejaculated into the vagina, most of it accumulates in the posterior fornix of the vagina, and the cervical opening is immersed in this pool of semen. Under normal circumstances, sperm can enter the cervical canal after a few minutes. The normal vaginal environment is acidic, which has important physiological significance for the self-cleaning function of the vagina, but is not conducive to the activity and survival of sperm.

How does sperm pass through the cervix?

Whether sperm can pass through the cervix is ​​closely related to the biochemical properties of cervical mucus. The secretion of cervical mucus is directly affected by the levels of estrogen and progesterone secreted by the ovaries. Before ovulation, the mature follicles secrete a large amount of estrogen, which makes the cervical mucus thinner, clear and transparent like egg white, and the amount also increases. It contains nutrients such as sugar, vitamins and salts, which provide energy for sperm activity. The cervix acts as a screening mechanism for sperm; only sperm with normal morphology and high motility can pass through the cervix smoothly. Furthermore, there is a substance in the seminal plasma that inhibits sperm activation and attaches to the sperm head. When the sperm passes through the cervical mucus, these substances can be removed and the sperm can gain the ability to fertilize. This process is called capacitation.

How does sperm move in the uterine cavity?

After the sperm passes through the cervix and enters the uterine cavity, it continues to swim upward with the help of the uterine cavity fluid and generally does not stay in the uterus. The sperm passes through the uterine horns and reaches the isthmus of the fallopian tube. Of course, sperm can pass through both fallopian tubes, unless there is obstruction in the fallopian tubes and it cannot pass through.

How does sperm pass through the fallopian tube?

Sperm moves in the fallopian tube mainly through the brief segmental contraction of the fallopian tube muscle wall, which causes the sperm and tubal fluid to flow to the ampulla of the fallopian tube. The fallopian tube epithelial cells have countless cilia, which swing from the fimbria toward the uterine cavity. After the egg escapes from the ruptured mature follicle, it is captured by the fimbria of the fallopian tube. The egg itself has no ability to move. Its movement depends on the contraction of the smooth muscle of the fallopian tube and the cilia movement of the epithelium, and it moves passively toward the uterine cavity.

Here, the fertilized egg combines with the sperm swimming upstream and is fertilized. The fertilized egg passively moves into the uterine cavity and implants in the endometrium, and a new life begins.