Prenatal Development

Germinal Period

The first stage of prenatal development, lasting approximately 2 weeks, which includes fertilization, formation of the zygote, and implantation.

Embryonic Period

The second stage of prenatal development, occurring from implantation to the 8th week, during which the three germ layers (ectoderm, mesoderm, and endoderm) form and major organ systems develop.

Fetal Stage

The third and final stage of prenatal development, lasting from the 9th week until birth, characterized by rapid growth, organ maturation, and the development of sensory and behavioral capacities.

Amniotic Fluid

Fluid surrounding the developing fetus that regulates temperature and protects the baby from sudden movements.

Chorion

The outermost membrane surrounding the amnion, which forms finger-like villi that attach to the uterus and helps in the formation of the placenta.

Placenta

An organ that develops during pregnancy and acts as a bridge between the mother's and fetus's blood vessels, allowing the transfer of nutrients and waste.

Ectoderm

One of the three germ layers formed during the embryonic period, responsible for the development of the nervous system and skin.

Mesoderm

One of the three germ layers formed during the embryonic period, responsible for the development of the skeleton, muscles, and circulatory system.

Endoderm

One of the three germ layers formed during the embryonic period, responsible for the development of the digestive system, lungs, urinary tracts, and glands.

Vernix

A white, cheeselike substance that forms on the fetus during the second trimester, preventing chapping of the skin in the amniotic fluid.

Lanugo

Fine, downy hair that appears on the fetus during the second trimester, helping the vernix stick to the skin.

Teratogens

Environmental agents that can cause damage during the prenatal period, leading to birth defects or developmental abnormalities.

Fetal Alcohol Syndrome (FAS)

A condition caused by maternal alcohol consumption during pregnancy, characterized by slow physical growth, facial abnormalities, and brain injury.

Radiation

A teratogen that can lead to prematurity, physical abnormalities, and slow physical development in the fetus.