How is a zygote transported to the uterus?
The correct answer and explanation is:
The zygote is transported to the uterus through the fallopian tube, a process that typically takes about 3 to 4 days after fertilization.
After sperm fertilizes the egg in the ampulla of the fallopian tube, the zygote begins dividing. This division results in the formation of a ball of cells called a blastocyst. During this time, the cilia, tiny hair-like structures lining the fallopian tube, beat in a coordinated rhythm. The movement of these cilia, along with muscular contractions of the fallopian tube, helps to push the developing zygote toward the uterus.
The smooth muscles in the fallopian tube also contract, aiding the movement of the zygote. The zygote is not entirely passive in this journey. During its passage, it is nourished by the cells lining the fallopian tube, which secrete nutrients that support its growth. As the zygote travels, it transforms into a blastocyst, ready to implant into the uterine wall.
Once the blastocyst reaches the uterus, it encounters the endometrial lining, which has thickened in preparation for implantation. The blastocyst then attaches to the endometrial lining, starting the process of implantation. This is the beginning of pregnancy.
In summary, the zygote’s transport to the uterus is a highly coordinated process that involves ciliary movement, muscular contractions, and secretions from the fallopian tube. This ensures that the zygote is nurtured and protected until it reaches the uterus, where it can implant and continue developing.