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• Prenatal development

  Process of growth and maturation that occurs before birth, starting from conception and continuing until delivery
• Germinal Period

  1. Takes place in the first two weeks after conception

  2. Includes the creation of the zygote which transitions from a single-cell organism to a multicellular structure
• Blastocyst

  Inner layer of cells that develops during the germinal period, implants itself into the uterine lining, and later develops into the embryo
• Trophoblast

  Outer layer of cells that develops in the germinal period, provides nutrition and support for the embryo
• Embryonic Period

  1. Occurs two to eight weeks after conception

  2. The rate of cell differentiation intensifies, support systems for the cells form, and organs appear
• Organogenesis

  Process of organ formation, organs are especially vulnerable to environmental changes while they are being formed
• Embryonic Period

  1. The heart begins to beat, and the circulatory system starts to form

  2. Limb buds emerge and develop into arms and legs

  3. The embryo is highly susceptible to teratogens
• Placenta

  Temporary organ that develops during early pregnancy and serves as the interface between the maternal and fetal circulatory systems, facilitates the exchange of nutrients, oxygen, and waste products
• Umbilical cord

  Contains blood vessels that transport oxygenated blood and nutrients from the placenta to the embryo/fetus and carry deoxygenated blood and waste products away from the embryo/fetus for disposal by the maternal circulation
• Amniotic sac

  Fluid-filled membrane that surrounds and protects the developing embryo by cushioning against physical impacts, forms from the fusion of the amnion (inner membrane) and the chorion (outer membrane) and begins to fill with amniotic fluid
• Fetal Period

  1. Lasting about seven months, is the prenatal period between two months after conception and birth in typical pregnancies

  2. The embryo is now referred to as a fetus, and its major organs and systems continue to develop and mature

  3. The fetus is less susceptible to teratogens compared to the embryonic period, but environmental influences can still impact its development