Human Embryology and Development

Flashcards covering key terms and concepts about human embryology and development.

Fertilization

The process in which a sperm cell fuses with an oocyte to form a zygote.

Polyspermy

A condition in which more than one sperm fertilizes an oocyte, which is prevented by the hardening of the zona pellucida.

Blastocyst

A structure formed in the early development of mammals consisting of an inner cell mass that will develop into the embryo and an outer trophoblast that will form the placenta.

HCG (Human Chorionic Gonadotropin)

A hormone secreted by the trophoblast of the blastocyst that stimulates the growth of the corpus luteum and helps maintain pregnancy.

Amniotic Fluid

The fluid surrounding the embryo that provides cushioning and protection during development.

In Vitro Fertilization

A reproductive technology involving the fertilization of an egg outside the body followed by implantation of the resulting embryo in the uterus.

Implantation

The process by which the blastocyst adheres to the endometrium of the uterus and establishes a connection for nutrient exchange.

Corpus Luteum

A hormone-secreting structure that develops from the ovary after ovulation and produces progesterone and estrogen to support pregnancy.

Pre-embryonic Development

The early stages of embryo development including zygote, cleavage, morula, and blastocyst stages before implantation.

Trophoblast

The outer layer of cells of the blastocyst that eventually forms the placenta and secretes hormones necessary for pregnancy.