Fetal Development Quiz: Stages of Prenatal Development

Study Notes

Stages of Prenatal Development

Prenatal development consists of three stages: zygote, embryo, and fetus.
The zygote stage lasts from conception to implantation (10-14 days), during which the fertilized egg travels to the uterus.
The embryo stage spans from implantation through the 8th week, characterized by the formation of major organs from cell layers.
The fetus stage lasts 7 months, marked by rapid growth and refinement of organs.

Maternal Health Behavior

Healthy choices before pregnancy are crucial for fetal development, including proper nutrition, no alcohol consumption, and sufficient rest.
Risks early on can impact birth weight, cognitive development, and birth defects.

The Zygote

The zygote travels to the uterus and divides into a ball-like blastocyst.
Cell differentiation begins, with the inner cell layer forming the embryo and the outer layer forming protective tissues.

Support Systems

The amnion is a fluid-filled sac that cushions the fetus.
The yolk sac produces blood cells for the embryo.
The chorion becomes the placenta lining, gathering nutrients for the embryo.
The umbilical cord transports waste from the embryo and delivers oxygen and nutrients from the placenta.

The Embryo

Cells differentiate into ectoderm, mesoderm, and endoderm.
The neural tube forms the spine and brain, and the heart begins to beat.
Organs start forming during this stage.

Sexual Differentiation

Sexual differentiation begins in the 7th-8th week, with the presence of a Y chromosome triggering testes development in males.
In the absence of a Y chromosome, ovaries develop in females.

The Fetus

All major organs become functional during this stage.
Rapid refinement of systems occurs, and movement, senses, and behavior emerge.
The fetus begins to move (kicking, twisting) and sexual differentiation becomes visible on ultrasound by the 3rd month.
Complex mouth and throat movements emerge, and responses to sound and light are detected by 25 weeks.
Organs prepare for birth, and viability outside the womb is possible after 28 weeks.
Activity slows, and sleep increases near birth.

Sensory Development

Hearing and touch emerge first, followed by vision, which is the least developed sense at birth.
Premature fetuses provide insight into sensory development.

Neurobehavioral Development

Fetal health is assessed by monitoring motor activity, heart rate, behavioral state, and responsiveness.
This includes startles, stretching, and eye movement patterns.
Heart rate reduction indicates development, and the fetus responds more vigorously to stimulation from outside the uterus.
Behavioral states, including quiet sleep, active sleep, quiet awake, and active awake, emerge around 36 weeks.

Description

Test your knowledge on the stages of prenatal development, including Zygote, Embryo, and Fetus, as well as the importance of maternal health behavior during pregnancy. Learn about the timeline, major milestones, and risks associated with each stage.