PSYCH100 Exam 4

germinal stage

• (0-2 weeks after conception)

  • Fertilization: sperm + egg → zygote

  • Zygote travels to the uterus

  • Implantation: zygote attaches to the uterine wall

embryotic stage

• (3-8 weeks)

  • Embryo: a developing organism inside the amniotic sac

  • The placenta exchanges nutrients and waste between the mother and the embryo

  • Major organs begin to develop

  • Neural tube forms → develops into the nervous system

fetal stage

• (9 weeks → birth)

  • By about 12 weeks, all major organ systems are formed

  • Around 24 weeks of pregnancy, the fetus approaches the age of viability (can potentially survive outside the womb) with medical help

Premature infants have a higher risk of health and developmental problems

spina bifida

a birth defect in which the spine and spinal cord don’t develop properly during early pregnancy

teratogen

any agent that can harm the zygote, embryo, or fetus

sudden infant death syndrome (SIDS)

the sudden and unexplained death of infants that usually occurs when they are asleep in their cribs

fetal alcohol syndrome (FAS)

caused by maternal use of alcohol during pregnancy and is a leading cause of intellectual disability (low IQ)

reflex

an unlearned, automatic response to a stimulus, has important survival value