neonate umbilical cord Chapter 3 Chapter 3 germinal stage placenta Chapter 3 Chapter 3 blastocyst embryonic stage Chapter 3 Chapter 3 embryonic disk cephalocaudal Chapter 3 Chapter 3 trophoblast proximodistal Chapter 3 Chapter 3 A tube that connects the fetus to the placenta. A newborn baby. Chapter 3 Chapter 3 An organ connected to the uterine wall and to the fetus by the umbilical cord. The placenta The period of development between conception serves as a filter between mother and fetus for and the implantation of the embryo. the exchange of nutrients and wastes. Chapter 3 Chapter 3 The stage of prenatal development that lasts A stage within the germinal period of prenatal from implantation through the eighth week of development in which the zygote has the form pregnancy; it is characterized by the of a sphere of cells surrounding a cavity of fluid. development of the major organ systems. Chapter 3 Chapter 3 The platelike inner part of the blastocyst that From head to tail. differentiates into the ectoderm, mesoderm, and endoderm of the embryo. Chapter 3 Chapter 3 The outer part of the blastocyst from which the From the inner part (or axis) of the body amniotic sac, placenta, and umbilical cord outward. develop. Chapter 3 Chapter 3 ectoderm amniotic sac Chapter 3 Chapter 3 neural tube amniotic fluid Chapter 3 Chapter 3 endoderm fetal stage Chapter 3 Chapter 3 mesoderm stillbirth Chapter 3 Chapter 3 androgens teratogens Chapter 3 Chapter 3 The outermost cell layer of the newly formed The sac containing the fetus. embryo from which the skin and nervous system develop. Chapter 3 Chapter 3 A structure that forms in the ectoderm during Fluid within the amniotic sac that suspends and the embryonic stage, from which the nervous protects the fetus. system develops. Chapter 3 Chapter 3 The stage of development that lasts from the beginning of the ninth week of pregnancy The inner layer of the embryo from which the through birth; it is characterized by gains in size lungs and digestive system develop. and weight and by maturation of the organ systems. Chapter 3 Chapter 3 The central layer of the embryo from which the The delivery of a dead fetus. bones and muscles develop. Chapter 3 Chapter 3 Environmental influences or agents that can Male sex hormones. damage the embryo or fetus. Chapter 3 Chapter 3 critical period toxemia Chapter 3 Chapter 3 syphilis premature Chapter 3 Chapter 3 congenital Rh incompatibility Chapter 3 Chapter 3 HIV/AIDS thalidomide Chapter 3 Chapter 3 rubella progestin Chapter 3 Chapter 3 A life-threatening disease that can afflict In this usage, a period during which an embryo pregnant women; it is characterized by high or fetus is particularly vulnerable to a certain blood pressure. teratogen. Chapter 3 Chapter 3 A sexually transmitted infection that, in Born before the full term of gestation. Also advanced stages, can attack major organ referred to as preterm. systems. Chapter 3 Chapter 3 A condition in which antibodies produced by Present at birth; resulting from the prenatal the mother are transmitted to the child, possibly environment. causing brain damage or death. Chapter 3 Chapter 3 HIV stands for human immunodeficiency virus, which cripples the body’s immune system. AIDS A sedative used in the 1960s that has been stands for acquired immunodeficiency syndrome, a linked to birth defects, especially deformed or condition in which the immune system is absent limbs. weakened and the body becomes vulnerable to a variety of fatal illnesses. Chapter 3 Chapter 3 A viral infection that can cause retardation and A hormone used to maintain pregnancy that heart disease in the embryo. Also called German can cause masculinization of the fetus. measles. Chapter 3 Chapter 3 DES Chapter 3 fetal alcohol syndrome (FAS) Chapter 3 Diethylstilbestrol, an estrogen that has been linked to cancer in the reproductive organs of children of women who used the hormone when pregnant. Chapter 3 A cluster of symptoms shown by children of women who drank heavily during pregnancy, including characteristic facial features and mental retardation. Chapter 3.