Lesson 2: Early Physical Development

teratogens

agents that can damage an embryo or fetus

teratogens can include…

viruses, alcohol, nicotine, cocaine, and caffeine

fetal alcohol spectrum disorder (FASD)

disorder characterized by physical and cognitive function deficits in children caused by heavy alcohol consumption by the pregnant parent

in severe cases of FASD, symptoms can include…

a small, out-of-proportion head and distinct facial features

maturation

biological growth processes that enable orderly changes in behavior; relatively uninfluenced by experience

habituation

decreasing responsiveness with repeated stimulation

as infants gain familiarity with repeated exposure to a stimulus…

their interest wanes and they look away sooner

gross motor skills

skills involving large muscles and whole-body movement

infantile amnesia

inability to recall memories from one’s infancy

fine motor skills

skills involving the small muscles of the body

critical period

limited developmental window in which the brain is exceptionally receptive to specific environmental stimuli for developing key functions

embryo

developing human organism between 2 and 8 weeks after conception; formed by the inner cells

placenta

organ that transfers nutrients and oxygen from mother to embryo and screens out many harmful substances; formed by the outer cells of the zygote

fetus

human organism lasting from the 9th week after conception to birth

FASD occurs because…

drugs have epigenetic effects, leaving chemical marks on DNA that switch genes abnormally on or off

from ages 3 to 6, the most rapid brain growth occurs in…

the frontal lobes

the last cortical areas to develop are…

the association areas

reflexes that help infants stay close to their caregivers include the…

grasping reflex and startle reflex

zygotic stage (germinal stage)

prenatal stage that begins at conception, lasts 2-3 weeks, and involves the zygote undergoing cell division, travelling down the fallopian tube to the uterus, and implanting itself into the uterine lining

embryonic stage

prenatal stage that begins 2-3 weeks after conception, lasts until 6-8 weeks after conception, and involves the embryo beginning to develop rudimentary limbs and major organs

fetal stage

prenatal stage that begins 8-10 weeks after conception, lasts until birth, and involves the fetus’s body and organs continuing to mature and grow and the fetus showing signs of hearing and vision