Module 3.2a Physical Development Across the Lifespan: Prenatal Development, Infancy, and Childhood

Developmental psychology

The branch of psychology that studies physical, cognitive, and social change throughout the human lifespan.

Zygote

A fertilized egg; the cell formed by the union of a sperm and an egg.

Cell division

The process by which cells duplicate and multiply, creating identical cells during early prenatal development.

Differentiation

The process by which cells begin to specialize in structure and function during prenatal development.

Germinal stage

The first stage of prenatal development, lasting about 10-14 days after conception, ending when the zygote attaches to the uterine wall.

Embryo

The developing human organism from about 2 weeks after fertilization through the 8th week.

Placenta

The life-link organ formed from outer embryonic cells that transfers nutrients and oxygen from mother to embryo while removing waste.

Fetus

The developing human organism from 9 weeks after conception to birth.

Teratogens

Agents such as viruses, drugs, or chemicals that can cross the placental barrier and harm an embryo or fetus.

Congenital

Present at birth, as in congenital disabilities.

Fetal alcohol spectrum disorder (FASD)

A range of physical, behavioral, and cognitive effects that can occur in individuals whose mothers drank alcohol during pregnancy.

Fetal alcohol syndrome (FAS)

The most severe form of FASD, marked by lifelong physical and mental abnormalities.

Epigenetic effects

Changes in gene expression that occur without changes to the underlying DNA sequence, such as when substances like alcohol leave chemical marks on DNA that switch genes abnormally on or off.

Prenatal learning

The capacity of fetuses to learn and remember, demonstrated through responses to sounds and other stimuli before birth.

Environmental factors

External conditions that can affect prenatal development, including sounds, maternal nutrition, stress, and exposure to teratogens.