Presentation on theme: "Human Development Prenatal, Infancy, & Early Childhood."— Presentation transcript:
Human Development Prenatal, Infancy, & Early Childhood
Prenatal Period Stage 1: Germinal (conception- 2wk) Ovum + Sperm = fertilized egg called a zygote (46 chromosomes, 23 from each parent) Zygote starts as a single cell & begins to divide 2wk it attaches to the wall of the uterus & placenta forms (this is the beginning of the next stage) Many zygotes rejected at this point (1 in 5 pregnancies end with woman not aware she was pregnant)
Genetic Abnormalities Turner syndrome: XO Sperm contributes nothing and baby develops female but can’t reproduce because don’t have reproductive organs Usually short
Genetic Abnormalities XXY Klinefelter’s syndrome Live as men, looks and raised male but small penis and testes. Low androgen secretion and possible female breast development A feminizing male
XXX Sperm contributes too much Looks female Tend to be normal female. Don’t even know they have it.
Stage 2: Embryonic (2-8 wk) Zygote is now called an embryo- begin to differentiate between bone, muscle & organs Very fragile since basic organs are begin formed (heart, spine, brain, genitalia) Teratogens- toxic agents that cross the placenta Major birth defects can occur & most miscarriages occur in this stage
Prenatal Hormone Abnormalities Andrenogenital Syndrome (AGS) Too much androgen is released to the fetus. Not a problem if you’re a male but females are masculine. Genitalia will masculinize and more like a tomboy. Androgen Insensitivity syndrome (AIS) Baby doesn’t detect androgen. Boys don’t masculinize they develop female (XY) No internal sex organs They are XY females. At puberty they grow breasts but do not menstruate.
Stage 3: Fetal (2 mo- birth) Embryo now called a fetus Vital organs develop & physical characteristics distinctly human Capable of physical movement Respiratory & digestive system matures wk fetus may reach age of viability- can survive in the event of premature birth wk survival rate 85%
Birth Premature- the more premature and underweight the baby is the greater chance of physical & mental impairment Power of Touch- premature babies gently massaged 3x a day show significant weight gain, more rapidly maturing nervous system, & higher activity Anoxia- loss of oxygen to nerve cells can lead to motor paralysis (cerebral palsy)
Some Influences on Prenatal Dev. 1. Severe Maternal Malnutrition Increase risk of birth complications & neurological defects Often confounded with poverty, drug use, & limited access to health care 2. All Recreational Drugs (E.I- cocaine, narcotics) Born addicted Increase risk of early death due to prematurity Birth defects- particularly respiratory problems
Some Influences on Prenatal Dev. 3. Alcohol- Fetal Alcohol Syndrome Correlation btw amount of alcohol consumed & damage to offspring Microcephaly (small head), heart defects, hyperactivity, delayed mental & motor skills, leading cause of mental retardation Increase incidence of depression, suicide, & criminal behavior in adulthood 4. Smoking Increase risk of miscarriage, prematurity & sudden infant death syndrome (SIDS) Slower cognitive development, ADD
Cross-Cultural Comparison of Infant Mortality Infant mortality is the death rate per 1,000 births during 1 st year of life US ranks only 21 st in the prevention of infant mortality Why?
Infant Mortality Rates
Reflexes at Birth Rooting- turn head toward anything that touches cheek Sucking- suck on anything that enters mouth Swallowing- swallow liquids w/o choking Grasping- wrap their fist around anything that enters their hand Stepping- make stepping motion if held just above the ground
Sensory Dev Vision 1-3 mo distinguish mom’s face with that of a stranger Imitates facial expressions of an adult 3-4 years have visual abilities equal to an adult Hearing 1 mo keen hearing & can discriminate between small sound variations such as bah & pah 6 mo have developed ability to make all sounds necessary to learn language mo first words Smell & Taste 1 day old can tell difference between citrus & floral odor 6 wk can smell difference between their mom & a stranger Innate taste preference for sweet things
Maturation- developmental changes that are biologically programmed rather than learned Walking- all humans learn it but sometimes when we learn it depends on culture Head size decreases in proportion to body size as one gets older In first 3 mo babies’ body weight & brain size doubles Developmental Norms- average age at which children perform various tasks
Gross Motor Skills (larger muscles of the body) 5.5 mo- sitting up alone 10 mo- crawling 1 yr- walk alone 1.5 yr- up and down stairs
Fine Motor Skills (smaller muscles of the body) 2 yr- clumsy at picking up objects, can hold cup with one hand, start to use spoon 3 yr- use scissor & button clothes 4 yr- change clothes by themselves, eat with utensils 5 yr- begin to write
Drawing- type of fine motor skill Serves purpose of sensory exploration & to express emotion Pre-representational- scribbles, focus is on activity itself Representational- drawing means something to the child, 4 yr old can draw stick figures