Transcript Chapter 10 - Gordon State College

LIFESPAN
PHYSICAL DEVELOPMENT
FELDMAN:
MODULE 3-1
NORMAL GROWTH
 Growth occurs in a cephalocaudal (head to tail) pattern
The head takes up one-fourth of total body length at
birth, but only one-fifth at age 2.
 Growth occurs in a proximodistal (near to far) pattern.
The head, chest and trunk precede the limbs and
extremities.
BODY GROWTH IN INFANCY
Average North American newborn weight 7 ½ pounds and is
20 inches long.
Birth weight triples in one year and quadruples by the end
of two years.
By the second year, the child is at 1/5 of its adult weight
(30 lbs.) and ½ its adult height (30 + inches).
Muscle tissue increases very slowly.
FACTS ABOUT PHYSICAL GROWTH
EARLY CHILDHOOD
2-3 inches per year
5 pounds per year
Baby fat declines
Posture and balance
improve due to lower
center of gravity.
MIDDLE CHILDHOOD
2-3 inches per year
5 pounds per year
Bones harden (skeletal age),
lengthen and broaden
ligaments are not yet firmly
attached.
Improved strength and muscle tone.
Primary teeth are replaced with
permanent teeth
BODY GROWTH AND GENDER
Girls are shorter and lighter and have a higher
ratio of body fat to muscle than boys.
Children differ in the rate of physical growth.
Skeletal age is the best way to estimate the child’s
physical maturity.
African Americans mature faster than Caucasians
and girls mature faster than boys.
MOTOR DEVELOPMENT
.Gross motor development involves large muscle groups and activities that
generally have to do with locomotion
Fine motor development involves smaller muscle groups and activities such as
reaching and grasping
PERSPECTIVES ON MOTOR
DEVELOPMENT
Nature-focused view:
 Developmental maturation
Nurture-focused view:
 Dynamic systems theory: the child develops new motor skills by adapting and
adding to old ones to meet his/her goals
DYNAMIC SYSTEMS THEORY OF
MOTOR DEVELOPMENT
Mastery of motor skills involves acquiring increasingly complex systems of
action.
Each new skill is a joint product of:
 1) Central nervous system development
 2) movement capacities of the body
 3) goals of the child
 4) environmental supports for the skill
NEWBORN REFLEXES
blinking
grasping
rooting
sucking
Babinski
Moro
stepping
swimming
GROSS MOTOR
DEVELOPMENT
Gross motor development follows a generally
universal sequence.
Cephalocaudal and proximodistal trends are evident.
There is no fixed maturational timetable.
AGE NORMS (IN MONTHS) FOR GROSS
MOTOR SKILLS*
CULTURAL VARIATIONS IN
MOTOR DEVELOPMENT
Iranian orphans are not encouraged to
move
Indians in Southern Mexico are discouraged
from walking
Kipsigi parents in Kenya encourage motor
skills and children walk early
GROSS MOTOR - PRESCHOOL
Age 3 – hop, jump, run for the fun of it
Ages 4 and 5 – more adventurous, climb
USING COMMON SENSE
For adequate motor development, preschoolers
need places and opportunities to play
There is no evidence that formal lessons facilitate
development
Pushing the child may undermine self confidence
GROSS MOTOR – SCHOOL CHILDREN
Skipping rope, swimming, bike-riding, skating
10-11 year olds can learn from sports
Gain greater control over muscles
Boys outperform girls
Need opportunities for physical play
ORGANIZED SPORTS IN CHILDHOOD POSITIVES
 Opportunities for exercise
 Learning to compete
 Opportunities for peer, friendship relationships
 Reduces tendency for obesity
ORGANIZED SPORTS IN CHILDHOOD NEGATIVES
Negatives
Too much pressure to perform
 Physical injuries
 Distraction from academic work
 Unrealistic expectations as an athlete
 Wrong values
 Possible exploitation
GROSS MOTOR - ADULTHOOD
Gross motor skills improve in adolescence
They peak in the 20’s
They decline through the remainder of adulthood
FINE MOTOR SKILLS
INFANCY - SEQUENCE OF REACHING BEHAVIOR
Newborns pre-reach (drops out about 7 weeks)
Voluntary reaching appears at about 3 months
By 4-6 months an infant can grasp an object in
a darkened room.
By 7 months they can use one arm
SEQUENCE OF GRASPING BEHAVIOR
Newborn grasping reflex
palmar grasp – can be varied
4-5 months, transfer objects from hand to hand
1 year – pincer grasp
(Trying to push infants beyond their readiness
may backfire.)
FINE MOTOR SKILLS INFANCY
Reaching affects cognitive development
because it opens up new ways of exploring
the environment.
Infants use proprioceptive cues to reach as
early as 4 months
REACHING & GRASPING IN
INFANCY
Perceptual-motor coupling is used
sense of touch
sense of vision by 8 months
Experience plays a role in development
Pincer grasp goes with crawling & children pick up things
from floor.
FINE MOTOR – EARLY CHILDHOOD
Fine motor progress is apparent in
Children’s care of their own bodies
Drawing and painting
SELF-HELP SKILLS
2-3 years zips, puts on clothes
3-4 years button (large buttons)
5-6 years ties shoes
2-3 years
3-4 years
4-5 years
5-6 years
uses spoon
serves self food
uses fork
uses knife
DRAWING AND PAINTING
3-4 years
 copies vertical line/circle
 Draws a “tadpole” person
4-5 years
 Cuts with scissors
 Copies triangle, cross, some letters
5-6 years
 Draws person with 6 parts
 Copies some numbers, simple words
FINE MOTOR – MIDDLE
CHILDHOOD
Increased myelination of CNS
6-year-olds can hammer, paste, tie shoes, fasten clothes
7 years – use pencil & print smaller
8-10 years – write cursive & use hands independently
12 years – approach adult skill levels
Girls outperform boys
FINE MOTOR – OLDER ADULTHOOD
Slower motor behavior
Neural noise – irregular neural activity in the
CNS
Strategy – may have to slow to perform
accurately
Can learn new motor tasks, but more practice
required
INFLUENCES ON PHYSICAL GROWTH & HEALTH
Genetics
Infectious disease
Childhood injuries
Hormones
Emotional well-being
Nutrition
CHILDREN’S HEALTH - PREVENTION
Immunization
 Meningitis, measles, rubella, mumps, chicken pox, polio
Accidents
 Poisonings, falls, drowning, choking
Poverty
 Good medical care, nutrition, living conditions
INFLUENCES ON PHYSICAL GROWTH &
HEALTH - IMMUNIZATION
Immunization has caused a dramatic decline in
childhood diseases in the industrialized world
24% of American preschoolers lack essential
immunizations (40% in poverty)
Availability of care
Misconceptions (MMR & autism)
INFLUENCES ON PHYSICAL GROWTH & HEALTH
– PITUITARY GROWTH HORMONES
Growth hormone (GH) needed for development of all
body tissues except CNS & genitals
Thyroid-stimulating hormone (TSH) causes the
thyroid gland to release thyroxin, needed for
normal nerve cell development and for GH to have
a full impact on body size
INFLUENCES ON PHYSICAL GROWTH &
HEALTH – EMOTIONAL WELL BEING
Psychosocial dwarfism
 Caused by extreme emotional deprivation
 Appears between 2 & 15 years of age
 Can interfere with the production of GH
 Very short stature
 Immature skeletal age
 Severe adjustment problems
 Can be treated
THE GROWTH SPURT OF PUBERTY
Most rapid growth since infancy
Average of age 9 for girls; 11 for boys
Girls grow 3.5 inches/year; boys 4 inches
50% of body weight gained in adolescence
Also changes in leg length and facial structure
WHY DOES PUBERTY HAPPEN EARLIER THAN IT
USED TO?
Nutrition ? – Better than in earlier times
Hormones ? – Found in food supply
Stress ?
Fat ?
STRESS THEORY OF EARLY PUBERTY
Hypothalamus  pituitary sex glands  produce
gonadotrophins
Androgens (testosterone)
Estrogens (estradiol)
Pituitary  thyroid gland  produces growth hormone
Cortisol (stress hormone) may trigger early onset (pituitary
activity)
FAT THEORY OF EARLY PUBERTY
Weight affects the timing of menarche (106 +/- 3
pounds)
Athletes and anorexics become amenorrheic
Fat and leptin may also be influential
ADULTHOOD
NORMAL PHYSICAL DEVELOPMENT:
EARLY & MIDDLE ADULTHOOD
Early Adulthood, peak muscle tone & joint function
Senescence
Middle Adulthood – gradual changes,
lose height, gain weight, in 40s & 50s skin sags,
wrinkles, age spots, hair thins, thicker finger- and
toenails, yellow teeth
CHANGES IN MIDDLE ADULTHOOD (CONT’D)
Sarcopenia – age-related loss of muscle mass &
strength
 Lose 1-2% per year starting at age 50
Exercise can help to reduce this loss
Also lose bone from the late 30’s; this accelerates in
the 50’s
CHANGES IN MIDDLE ADULTHOOD
Cholesterol increases
LDL – leads to atherosclerosis
Blood Pressure increases; sharply for women at
menopause
Metabolic disorder – hypertension, obesity, insulin
resistance, high cholesterol, low HDL, weight gain (Part of
normal aging?); weight loss & exercise help
Lungs become less elastic
ADULT HEALTH - REPRODUCTIVE SYSTEM
The 20’s are ideal for reproduction. Risks of miscarriage
and chromosomal disorders are reduced.
First births to women in their 30’s have increased in the
past two decades
Dramatic rise in fertility problems in the mid-thirties (14
to 26%)
CHANGES IN MIDDLE
ADULTHOOD - SEXUALITY
Climacteric – loss of fertility
Menopause – ceasing of menstrual cycles (average
age 52)
Drop in estrogen, hot flashes, nausea, fatigue, rapid
heartbeat
Gradual decline for men (no andropause)
ADULT HEALTH IMMUNE SYSTEM
Capacity declines after age 20, partially due to
thymus and inability to produce mature T cells
Stress and depression can also weaken the
immune system
ADULT HEALTH - STATES OF MIND
Western stereotype: deterioration is inevitable
 In one study, people with positive self-perceptions of aging
live 7 ½ years longer
 More optimistic elders are about capacity to cope with
physical challenge, better they are at overcoming threats to
health
 Low SES elders are less likely to believe they can control their
health, to seek medical treatment, or to follow doctors’
orders.
BIOLOGICAL THEORIES OF AGING
Cellular clock (Hayflick)
 70-80 cell divisions, based on telomeres
 120-year lifespan
Free-radical
 Calorie restriction
 antioxidants
Mitochondrial
 Cellular energy producers
 Linked to free radical theory
Hormonal Stress
 hypothalamic-pituitary-adrenal axis
 Stress & decline in immune function