What is the term for the process in which a blastocyst attaches to the wall of the uterus?

The process in which a blastocyst attaches to the wall of the uterus is called implantation. This is a critical step in human development following fertilization. After the sperm and egg fuse to form a zygote, the zygote undergoes several divisions and develops into a blastocyst as it travels down the fallopian tube to the uterus. Once it reaches the uterine cavity, the blastocyst must adhere to the uterine lining to establish a connection with the mother's blood supply, allowing for nutrient and oxygen exchange, which is essential for the continued development of the embryo.

In the reproductive process, fertilization, both external and internal, refers to the union of sperm and egg prior to this stage. External fertilization typically occurs in aquatic environments where eggs and sperm are released into the water, while internal fertilization involves sperm being introduced into the reproductive tract of the female. These processes precede implantation and are separate from the subsequent attachment of the blastocyst. Therefore, the correct term for when the blastocyst connects to the uterine wall is indeed implantation.