{ The Beginning of Development Conception to infancy

  1 st Trimester   Most dramatic growth/responsive to touch   Significant vulnerability to external environmental influences (from teratogens)   Conception Germinal period/zygote (weeks 1-2) Embryonic period/embryo (weeks 2-8) Fetal period/fetus (weeks 9-38) Critical periods begin (week 9)   Cells differentiate – become specialized in structure and function Prenatal Development

Zygote Embryo Fetus

Prenatal Development TypeExamplesPossible Effects CNS DepressantsAlcohol, tranquilizers, barbiturates, opiates Fetal Alcohol Syndrome (#1 & most preventable cause of mental retardation), addiction of fetus to drugs, deformities to face & body CNS StimulantsNicotine, amphetamines, cocaine Low birth weight, hyperactivity, increased susceptibility to SIDS STD’sHIV, herpes, syphilis, gonorrhea Baby born infected, skin & eye problems, CNS damage, increased risk of miscarriage Infectious Diseases German measles (Rubella), flu, chicken pox, tuberculosis, syphilis Mental retardation, damage to sensory systems, physical deformities, schizophrenia, low birth weight, increased risk of miscarriage Environmental toxins/pollutants Mercury, lead, PCB’s, radiation Mental retardation KNOWN CLASSES OF TERATOGENS (2001) Other teratogens: radiation from x-rays, inadequate diet, mother’s age

  2 nd Trimester   Dramatic size increase   Brain cells complete development   Nerve connex continue at high rate til 6   Skeletal & muscular systems fully formed   Hair growth, mother feels movement, facial features, organs begin to function Prenatal Development

  3 rd Trimester   28 weeks = age of viability   May be capable of learning   Length & weight increase (“fattening up”)   Avg. healthy baby = 6.5 – 8.5 lbs   Cont’d maturing of nervous system for self-regulation of vital functions Prenatal Development

  Capable of responding to stimulation from all senses   Taste distinction – preference for sweets   Vision:   1 month: color perception   4 months: focus on near or far objects   4-5 months: recognition of 2-D & 3-D   7 months: respond to different facials   Recognize mother’s voice   Ability to seek nourishment Neonatal Period (birth to 1 month)

Reflexes Babinski Reflex Rooting Reflex Sucking Reflex

Major Trends in Physical Development (conception to middle childhood)   Cephalocaudal (“head to tail”)   Growth progresses from head   Both size & muscular/skeletal control   Proximodistal (“near to far”)   Growth progresses from midline (spine)   Limbs extend from center   Control of “distal” parts progresses after control of parts of body close to middle

  Physical growth is key during 1 st year   Limitations may have negative impact on cognitive development if undetected   E.g. hearing impairment can impact speech   In first year, children triple birth weight & double height Major Trends in Physical Development (conception to middle childhood)

Motor Development Milestones