Human Growth & Development - Extra-embryonic Tissues

Flashcards covering key terms and concepts related to human growth and development, particularly focusing on extra-embryonic tissues.

Trophoblast

The outer layer of cells in a blastocyst that provides nutrients to the developing embryo and forms part of the placenta.

Amniotic Cavity

The fluid-filled space that surrounds and protects the embryo.

Embryonic Disc

A structure formed from the inner cell mass of the blastocyst that will develop into the embryo.

Ectoderm

The outermost layer of the embryonic germ layers that will develop into skin, nervous system, and other structures.

Mesoderm

The middle layer of the embryonic germ layers that will develop into muscle, bone, and circulatory systems.

Endoderm

The innermost layer of the embryonic germ layers that forms the lining of the gut and other internal organs.

Allantois

An embryonic structure involved in waste storage and gas exchange, contributing to the formation of the umbilical cord.

Yolk Sac

An extraembryonic membrane that provides nutrients to the developing embryo and is involved in blood cell production.

Chorion

The outermost membrane surrounding the embryo, contributing to the formation of the placenta.

Chorionic Villi

Finger-like projections of the chorion that invade the uterine lining and facilitate maternal-fetal nutrient exchange.

Extraembryonic Coelom

A cavity that forms within the extraembryonic mesoderm, surrounding the yolk sac and amniotic cavity.

Syncytiotrophoblast

The outer layer of the trophoblast that erodes maternal tissues to enable implantation.

Hypoblast

The layer of cells derived from the inner cell mass that eventually contributes to the formation of the yolk sac.

Epiblast

The layer of cells derived from the inner cell mass that eventually contributes to the formation of the embryo.

Primary Yolk Sac

The first yolk sac formed during embryonic development that provides early nutrition.

Secondary Yolk Sac

The yolk sac that forms after the primary yolk sac and plays a role in nutrient transport and blood cell production.

Allantois

A structure in vertebrate embryos that is involved in waste storage and gas exchange.

Placenta

An organ that connects the developing fetus to the uterine wall, providing nutrients and oxygen and removing waste.

Extraembryonic Mesoderm

The connective tissue layer that develops between the trophoblast and yolk sac, supporting the embryo.

Uteroplacental Circulation

The blood supply system established between the mother and the developing embryo through the placenta.