Transcript AutoCAD Architecture 2008: Part I: Getting Started

Biological Beginnings
Chapter 4
Child Development and Education, Fourth Edition
© 2010 Pearson Education, Inc.
All rights reserved.
Chapter Outline



Genetic foundations
Prenatal development
Birth of the baby
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
2
Genetic Foundations

Genes are contained on chromosomes
Chromosomes are made up of DNA

Most genes are universal



Some genes are diverse


basic human abilities: language, walking, running,
social communication
height, weight, activity levels, eagerness to learn,
emotionality, etc.
Genetic expression affected by time, environment
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
3
Formation of Reproductive Cells

Gametes: sperm (m) and ovum (f)


contain 23 chromosomes
form through meiosis




germ cells pair up
chromosomes replicate
crossing-over occurs
chromosomes separate and cell divides
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
4
Conception

Sperm fertilizes ovum


zygote has 23 + 23 chromosomes
gender determined on 23rd pair


XX; XY
Cells continue to divide


2 separate cell clusters: monozygotic twins
2 ova + 2 sperm: dizygotic twins
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
5
Genetic Transmission

Gene pairs include two alleles
 provide instructions for physical
characteristics
 dominant and recessive genes
 codominant genes
 most characteristics: polygenic
inheritance
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
6
Problems in Genetic Instruction

Chromosomal abnormalities




Single-gene defects


extra chromosome (e.g., Down syndrome)
missing or wrongly formed chromosome
1 in 150 births
inherited from one or both parents
Other problems


defective gene (e.g., Fragile X syndrome)
problem with multiple genes (e.g., Spina bifida)
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
7
Genetic Awakening


Occurs at different times in the lifespan
Some characteristics are canalized



Others more influenced by environment


canalization – tight genetic control
basic motor skills: crawling, sitting, walking
not canalized: reading, writing, math, social skills
Some characteristics awaken during sensitive
periods

perception, language, close bond to caregiver
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
8
Blending Heredity & Environment

Passive gene-environment relation



Active gene-environment relation



parents’ genetic tendencies influence child’s
environment
parents’ choice
child’s genetic characteristics influences his/her
environment
child’s choice
Evocative gene-environment relation


child’s genetic characteristics elicit responses from
environment
someone’s response to the child; not the child’s choice
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
9
Acknowledging Nature & Nurture
in Children’s Lives





Value individual differences
Remember that environment & genetics
influence every aspect of development
Intervene when children struggle
Be mindful of your reactions to children’s
challenging temperaments
Encourage children to make growth-promoting
choices
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
10
Prenatal Development

3 Phases of Prenatal Growth

zygote


embryo


conception – 2 weeks post
2 weeks – 8 weeks
fetus

8 weeks – birth
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
11
Development of Zygote

Begins at conception







ovum prevents additional sperm from entering
chromosomes combine to form zygote
Mitosis occurs
Attaches to uterine wall (~ 16 cells)
Separates into embryo & placenta
Releases hormones telling body to cease
menstruation
Cells begin to specialize

nervous system, brain
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
12
Development of Embryo

Life support sytem formed





placenta grows larger, stronger, and more refined
umbilical cord develops
provides food, liquid, oxygen; removes waste
secretes hormones to sustain embryonic growth
Basic body structures develop


from top to bottom (head first, feet last)
from inside to outside



torso before limbs; internal organs
arms & legs before hands & feet
fingers and toes recognizable at 8 weeks
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
13
Development of Fetus

Third month





Fourth month




head is large but growing slowly
eyes move into place; increasingly human-looking
genitalia form
reflex and muscular movement (although not felt)
rapid growth in length (height)
slow weight increase
hair growth on head and eyebrows
Fifth month



rapid growth in length (height) continues
fine hair growth covers body
movement felt by mother
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
14
Development of Fetus

Sixth month (avg. weight 1 lb. 13 oz.)



Seventh month (avg. weight 2 lb. 14 oz.)



skin red, wrinkled; body lean; fingernails evident
development of respiratory & central nervous system
eyes open; eyelashes and toenails form
body fills out
Eighth month (avg. weight 4 lb. 10 oz.)


skin becomes pink, smooth; fat grows beneath skin
testes descend (in males)
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
15
Development of Fetus

Brain development

preparation for reflexes


sucking, swallowing, looking away from light
activates circuits for sensing stimulation


can hear/remember music
can taste/recognize flavors
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
16
Preparing for Pregnancy





Starts before conception
Watch diet, take approved vitamin
supplements
Exercise
Avoid alcohol and drugs (includes OTC
meds)
See genetic counselor
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
17
Avoiding Teratogens

Potentially harmful substances





prescription or non-prescription drugs
infectious agents, e.g., rubella, syphilis, HIV
environmental chemicals, e.g., lead
maternal stress
Effects depend on amount, timing, genetic
makeup of mother & child


embryonic: development of body
fetal: development of brain
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
18
Medical Procedures


Ultrasonography
CVS (Chorionic Villus Sampling)




10-12 weeks
high-risk pregnancies
identifies chromosomal abnormalities, X-linked
disorders, some blood diseases
Amniocentesis


13-18 weeks
identifies neural tube defects & chromosomal
abnormalities
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
19
Supporting Parents, Protecting Babies










Encourage women to evaluate health before pregnancy
Remind sexually active individuals to take care
Encourage pregnant women to seek medical care
Use well-researched strategies to reach women at risk
for late or no prenatal care
Advise pregnant women from low-income backgrounds
about nutritional resources
Urge pregnant women to avoid teratogens
Encourage them to relax and speak their minds
Ask fathers about their experiences and feelings
Advise parents about care for children exposed to
teratogens
Intervene when mothers continue substance abuse
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
20
Birth of the Baby: Preparation



Childbirth classes
Select location and participants
Determine method of controlling pain
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
21
The Birth Process



Triggered by mother’s hormonal changes &
maturation of fetus
Braxton Hicks contractions begin
Fetus settles in head-downward position


Caesarean delivery if breech or sideways
Just before labor:


baby descends into pelvis
mother may experience




rush of energy
weight loss (1 to 4 pounds)
vaginal secretions
difficulty sleeping
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
22
Stages of Labor

First stage




Second stage



cervix dilated (10 cm)
baby proceeds down birth canal
Third stage


regular contractions
widening of cervix
pelvis and back pain
afterbirth expelled by uterus (placenta & fetal membranes)
Fourth stage

mother’s body readjusts
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
23
Medical Interventions


Induced labor using Pitocin
Analgesics




Anesthetics
Opioids/narcotics
Caesarean delivery


epidural analgesia (spinal injection)
in U.S., currently 30%
Medical personnel do their best to accommodate
women’s cultural practices
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
24
Babies at Risk

Born early (“premature”)



before the end of week 37
risk of breathing problems, anemia, brain
hemorrhages, feeding problems, instability in
temperature
Born small for date


possible neurological deficiencies, structural problems
with body parts, difficulty with breathing & vision
often due to exposure to teratogens or chromosomal
abnormalities
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
25
Guidelines for Care










Reduce infant’s exposure to light and noise.
Regulate amount of handling of infant by medical
staff.
Position baby to increase circulation.
Encourage parents to participate in care.
Inform parents about infant’s needs.
Arrange activities such as diapering & changing
clothes to minimize interruptions to sleep and rest.
Encourage parents to cuddle and carry infant.
Swaddle baby, with hands placed near the mouth.
Massage baby.
Educate parents about caring for the child as he or
she grows.
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
26
Enhancing Parents’ Sensitivity








Reassure new mothers that they will find necessary
energy and insight.
Share what you know about infants’ sensory & perceptual
abilities.
Point out physiological states.
Encourage families to watch infants’ responses to stimuli.
Ask families about the stimulation that infants find
soothing.
Model sensitive interactions with infants.
Show parents how to care for the baby.
Offer early and continued support to parents of fragile
infants.
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod
© 2010 Pearson Education, Inc.
All Rights Reserved.
27
Take-Home Messages



All children are born with
genetic instructions that
are mostly similar.
Unique gene differences
also predispose children
to look & act in different
ways.
Genetics and
environment affect
children’s abilities &
achievements.
Child Development and Education, Fourth Edition
Teresa M. McDevitt and Jeanne Ellis Ormrod



Prenatal growth consists
of three periods: zygote,
embryo, & fetus.
Avoiding teratogens,
seeking medical care,
reducing stress, nutrition,
and exercise are
important.
Family & professionals
are critical in guiding new
parents.
© 2010 Pearson Education, Inc.
All Rights Reserved.
28