PSYC200 Lecture 3: Week 3 Lecture
Overview
• Growth, motor development & health across:
• Infancy and toddlerhood
• Childhood
• Adolescence
• Adulthood
Growth: Infants & toddlers
Body Growth
• Changes in Body Size and Muscle Fat
(birth - 0 to 2 years)
• Physical growth is rapid
• Length increases 50% by first year, 75% by second
• (average 3.5kg starting weight) Weight doubles at 5 months, triples by first
year, and quadruples by second year
• Gains occur in growth spurts - 95% days are growth free
• Early rise in baby fat until 9 months - fat baby is good as they have reserve if
they're sick such as cold session
• Toddlers become more slender
Individual and group differences
• Skeletal age
• Measure of bone development - bone age same of chronological age
• Best way to measure physical development
• Girls are slightly shorter and lighter and have a higher ratio of fat to muscle
• Developmental problems and mortality rates vary by gender and race - historically
males more likely to die than females easier to catch disease as child due to shortage
with the Y
Changes in body proportions
• Cephalocaudal trend (head to tail or upper to lower)
• Growth of the head and chest occurs before that of the trunk and legs
Babies bigger head 13% body weight than adults 2% body weight
§
• Proximodistal trend (centre to extremities)
• Growth of the arms and legs occurs before that of the hands and feet
Brain development
Neurons
• At birth, the brain is nearer its adult size than any other physical structure
• 100 to 200 billion neurons
• Synapses
• Tiny gaps between neurons
• Neurons release chemicals that send messages
• Synaptic pruning
• Unused neurons die off
• Myelination
• Neural fibres are coated with fatty insulation - myelin -speeds up
messages
• Implications for development - also influenced by genetic program and
also environmental influence
Toddlers vocab spurt due to myelin speed up process of synapes
-
Brain development
• Critical and sensitive period for brain development = late prenatal & early infancy
• Brain has great plasticity - brain can recover from injury - nerouns that havent been
commited to process can adapt to the damage neurons job
• Experience "wires" a child's brain growth - normal balanced childhood - child learn
best by play
• Under-stimulation impairs development
• Possible to overwhelm children
Video on brain plasticity
- Jody 9 year old - removed the right hemisphere - due to seizures causing brain
cognitive problems
Seizure all coming from right hemisphere - disease took over the electricity in the
brain
-
Plasticity - Left hemisphere took over the jobs of the right hemisphere - allowed
her to gain function of the left side of the body and function in a normal way
again
-
Newborn capabilities
Reflexes
• Survival reflexes - clear adapt of value
REFLEXES DEVELOPMENTAL COURSE SIGNIFICANCE
Breathing reflex Permanent Provides oxygen;
expels carbon
Eye-bink Permanent Protects from light
and foreign objects
Pupillary relex; constrict
pupils
Permanent Adapts visual system
to low illumination
Rooting reflex; turning
cheek towards tactile
(touch)
Weakens by 2 months, disappears
by 5 mo
Orients child to breast
or bottle
Sucking reflex; suck objects
placed in mouth
Modified by experience over first
few months; disappears by 7
months
Allows child to take in
nutrients
Swallowing Permanent but modified with
experience
Take in nutrients;
protects choking
• Primitive reflexes, e.g., babinski, moro, stepping
REFLEXES DEVELOPMENTAL
COURSE
SIGNIFICANCE
Babinski; Fanning then curling toes
when bottom foot stroked
Disappears 12-18
mo
Present at birth and
disappearance Indicates
normal neurological
development
Grasping; curling fingers with objects
placed in palm
Disappears 3-4 mo;
replaced with
voluntary grasp
Present at birth and
disappearance Indicates
normal neurological
development
Moro; loud noise or sudden change
in position will cause to throw arms
outward, arch back then bring arms
back
Disappearance 4
mo
Present at birth and
disappearance Indicates
normal neurological
development
Swimming; active movements of
arms and legs; hold breathe
involuntarily
Disappear 4-6 mo Present at birth and
disappearance Indicates
normal neurological
development
Stepping; feet touch will as if to walk Disappear in first 8
weeks
Present at birth and
disappearance Indicates
normal neurological
development
Newborn capabilities
Behavioural states
• Infant needs 12-13 hours of sleep per day
• Develop organised sleep/wake pattern
• Brain development is responsible for changes in sleep and wakefulness
• Gradually coincide with a night and day schedule
• Newborns have 50% REM sleep - active sleep - 6 months 30% REM - adult 20%
• Why do infants sleep so much?
• Learning and memory processes
Growth
• Endocrine system + nervous system
• Pituitary gland produces growth hormone
• Inadequate growth hormone = stunted growth
Cylica disease
-
• Treatment = synthetic growth hormone
Influences on physical growth
• Heredity largely determines height and rate of physical growth
• Catch-up growth
• Growth returning to genetic path after environmentally caused delay
• Heredity and nutrition determine weight
Nutrition
• Baby’s energy needs are twice those of an adult, relative to their size
• 25% of infant's calories are devoted to growth - impairs brain develop
• Breast- versus bottle-feeding
• A weak correlation exists between weight in infancy and obesity at older ages
But other factors as well
-
Motor development: Infants & toddlers
Motor development 0 based on developmental norms or averages
• Gross motor development
Anything involve varse muscles
○
• Crawling, standing, and walking
• Fine motor development
Specific muscles
-
• Reaching and grasping
• Motor skills go from gross to fine movements:
• Pre-reaching
• Uncoordinated, primitive
• Ulnar grasp
• Clumsy, fingers close against palm
• Pincer grasp
• Coordinated use of forefinger and thumb
Motor skills as dynamic systems
• Mastery of motor skills involves acquiring increasingly complex dynamic systems of
action
• New skills are a joint product of:
• Central nervous system development
• Movement possibilities of the body
• Environmental supports for the skill
• Motivation of the child
Baby power!
• Illustrates large variation in abilities
• 7-month-old held onto bar for 33.67 secs
• Can stand on one foot
Growth: Childhood
Body growth
• Age 2 to puberty: grow 5-7cm and 2 kg per year
• Brain development
• Lateralisation - see behaviours associated with each hemisphere
Lateralization and Handedness
• Hand preference by age 2
• Dominant cerebral hemisphere
• Responsible for skilled motor action
• Right-handed: Lefthemisphere dominant
• Left-handed: Righthemisphere or motor and language maybe divided between
hemispheres
• Leftward orientation of fetus in uterus may promote right-side postural advantage
• Left and mixed-handed
• More likely to develop better verbal and math
• Higher rates of learning disabilities
Motor development: Childhood
Motor development
• Children can modify their movements to suit the environment
• Practice is particularly beneficial for children vs. adults
Gross motor development
• Center of gravity shifts downward to the trunk, and balance improves
• Preschooler's gait becomes smooth and rhythmic
• New skills like throwing and catching balls, riding a bike, and swinging on bars
emerge
Fine motor development
• Self-Help Skills
• Gradually become self- sufficient at dressing & feeding
• Drawing and Writing
• First drawings of a person by age 3 or 4
Individual & sex differences in motor skills
• Body build, ethnicity, sex, & opportunity for physical play influence development
• African-Americans have longer limbs for better leverage in running & jumping
• Boys are slightly ahead of girls in force & power
• Girls are better in fine motor & in certain gross motor skills (hopping and
skipping)
Health & wellness in childhood
Overweight & obesity
• Increasing trend of overweight/obese children in Australia
• Overweight = 85th-95th percentile for same age/sex
• Obese = >95th percentile
• Rates have tripled in past 30 years
• Challenges associated with excess weight
• Physical - diabetes, high blood pressure, heart problems
• Psychological
Adolescence
Growth spurt
Triggered by increase in growth hormones
Height
• Girl peak rate = just under 12 years
• Boy peak rate = 13.4 years
• Weight
• Girl peak rate = 12.5 years
• Boy peak rate = 13.9 years
• Girls gain extra fat, primarily in breasts, hip & buttocks
• Boys develop broader shoulders, larger skeletal muscles, heart and lung capacity
Motor Development
• Girls' gains in gross motor are gradual & level off at 14
• Boys show dramatic spurt in strength, speed, and endurance
• Separate PE classes often begins in high school when girls and boys are no longer well
matched physically
• Athletics provide lessons in competition, assertiveness, problem solving, and
teamwork
• Regular physical activity has lifelong benefits
Puberty
• Hormonal Changes
• Growth hormone & thyroxine contribute to body size and skeletal maturation
• Estrogens and androgens present in both sexes
• Testosterone in boys leads to muscle growth, body and facial hair, and other
sex characteristics
• Estrogen & progesterone cause girl's breasts, uterus, and vagina to mature,
body takes on feminine proportions, fat accumulates, and menstrual cycle begins
Sexual maturation
• Primary sexual characteristics
XX or XY •
Ovaries/testes •
Estrogen/testosterone •
• Vagina, fallopian tubes/penis, prostate, scrotum
• Secondary sexual characteristics
• Breasts, menstrual cycle, more body fat/ facial & body hair, relatively less body
fat
Sexual maturation
• Large variation for secondary sexual characteristics
• Girls: menstruation starts between 11-15 years
• Boys: sexual maturation begins with enlargement of testes & scrotum
• What determines rate of development?
Influences on sexual maturation
• Identical twins have first menstrual cycle within a month or two, fraternal twins differ
by 12 months
• Sharp rise in body weight & fat may trigger sexual maturation in females
• Secular trend
• In industrialized nations, age of first menstruation is now younger
• Why?
• Earlier when good nutrition, long life expectancies and high literacy
rates
• Earlier in stressful environment
Early vs. late development
• Effects depend on gender and time frame
• Boys –short-term
• Early = judged to be more socially competent, attractive & self-assured BUT at
greater risk for depression, and other problem behaviours
• Late = increased risk of anxiety & depression, less sure of self,
behaviour/adjustment problems
• Girls – short term
• Early = higher levels of body dissatisfaction, socialise with older peers
associated problems
• Late = some anxiety but outperform others academically
Role of Physical Attractiveness
• Society's image of an attractive female favours the late developer
• The male image is tall, broad-shouldered, and muscular—the early developer
• Body image
• Conception and attitude toward one's physical appearance
• Early maturing girl shave less positive bodyimage
• Early maturation linked to positive body image in males; late maturation linked to
dissatisfaction with physical self
Long-term effects of maturation rate
• Effects are greatest during adolescence & gradually reduce
• Slight increase in anxiety/depression in adulthood + lower education levels for early
maturing girls
• Can be direct flow-on effects, e.g., teen pregnancy
• Outcomes may not be culturally universal
Adolescent brain
MRI studies
• Volume of the brain’s grey matter increases, peaks and then decreases throughout
the teen years
• White matter increases in a linear fashion throughout adolescence
Health
Risk behaviour
• Leading cause of death among teenagers is unintentional injury
• Road traffic crash • Violence
• Suicide
• Alcohol, drug use and cigarette smoking compromise health + lead to bad decisions
Sleep patterns
• ‘Natural’ time for falling sleep pushed back
• Melatonin rises later at night for teenagers than adults
• Insufficient sleep during adolescence need 9.2 hours per night
• Sleep-deprived adolescents are less motivated, do worse in school, more depressed,
more irritable, have worse concentration + link to obesity
Nutritional Needs
• During growth spurt, boys require 2,700 calories a day & more protein
Girls require about 2,200 calories & less protein •
Iron, calcium, riboflavin, and magnesium deficiencies are common•
• Unhealthy fad diets
The Adult
Ageing process
• Signs of ageing
• Vision
• Hearing
• Taste
• Smell
• Touch
• Skin
• Weight
• Lack of physical activity
• Gradual decline in most bodily systems
Mobility
• Muscle strength declines at a faster rate
• Athletes retain muscular physique & strength into 60s & 70s
• By 60 to 70, 10-20% of muscle power is lost
• Exercise programs enhance joint flexibility and movement
• 30-50% after 70
• Bone strength deteriorates, as does flexibility & strength of tendons, ligaments &
joints
The changing brain
Brain continuously developing •
Normal ageing = gradual and relatively mild •
degeneration with the nervous system
• Brain more likely to remain active with exercise
Female menopause
Reproductive system ages •
Menopause = ending of women’s menstrual •
periods
• Average age = 50 years
• Gradual process
• Age of menopause consistent across time & cultures
Male andropause
• Slowly decreasing level of testosterone and a variety of symptoms including:
• Low libido
• Fatigue/lack of energy
• Erectile problems
• Memory problems
• Loss of pubic hair
• By age 80, men have 20-50% of testosterone they had at age 20
• Changes are gradual and variable
Ageing vs. disease, disuse or abuse?
• What is decline really due to?
• Disease
• Osteoporosis
• Osteoarthritis
• Disuse • Abuse
Longevity Quiz
• Start with average life expectancy
• 79 years for males
• 83 years for female
• Then add & subtract years as you answer each question to arrive at an idea of your
life expectancy
Longevity Quiz
+5yearsif≥2ofyourgrandparentslivedto80yearsormore •
-4yearsifanyparent,grandparentorsiblingdiedofheartattack •
or stroke before 50
• -2yearsifanyparent,grandparentorsiblingdiedfromthese diseases after age 50 but
before 60
• -3yearsforeachcaseofdiabetes,thyroiddisorder,breast cancer, cancer of the digestive
system, asthma or chronic bronchitis among parents or grandparents
• + 4 years if you are married. If you are over age 25 and not married, -1 year for every
year not married
• +2yearsifyourfamilyincomeplacesyouinthemiddle-classor higher SES category
• -3yearsifyouhavebeenpoormostofyourlife
• -1yearforevery4.5kgyouareoverweight
• -2yearsifyourbellymeasurementisbiggerthanyourchest measurement
+3yearsifyouareover40andnotoverweight •
+ 3 years if you exercise regularly and moderately •
Longevity Quiz
• + 2 years if your regular exercise is vigorous
• -3yearsifyourjobissedentaryor+3yearsifjobisactive
• +2yearsifyouarealightdrinker(1-3drinksperday)
• -5-10yearsifyouareaheavydrinker(4+drinksperday)
• -8yearsifyousmoke2+packsperday,iflessthanthis-2years
• +2yearsifyouareapractical&reasonableperson,-2yearsif you are aggressive, intense &
competitive
+1-3yearsifbasicallyhappy&contentwithlife •
-1-5yearsifoftenunhappy,worried&feelguilty •
+1yearifyouattended4yearsofeducationbeyondhighschool •
+3yearsifyouattended5+yearsbeyondhighschool •
+4yearsifyoulivedmostofyourlifeinruralenvironment •
-2yearsiflivedmostofyourlifeinurbanenvironment •
-5yearsifyousleep>9hoursperday •
+3yearsifyouhaveregularmedical&dentalcheck-ups •
+1yearifflossyourteetheveryday •
-2yearsiffrequentlyill •
Video – 80 year-old body builder
https://www.youtube.com/watch?v=AtizBP bDmF0
(Watch first 3 minutes)
Birth bones soft and difficult to
break
Additional calcium forms stronger bones
Week 3 Lecture
Monday, 12 March 2018
1:46 PM
Overview
• Growth, motor development & health across:
• Infancy and toddlerhood
• Childhood
• Adolescence
• Adulthood
Growth: Infants & toddlers
Body Growth
• Changes in Body Size and Muscle Fat
(birth - 0 to 2 years)
• Physical growth is rapid
• Length increases 50% by first year, 75% by second
• (average 3.5kg starting weight) Weight doubles at 5 months, triples by first
year, and quadruples by second year
• Gains occur in growth spurts - 95% days are growth free
• Early rise in baby fat until 9 months - fat baby is good as they have reserve if
they're sick such as cold session
• Toddlers become more slender
Individual and group differences
• Skeletal age
• Measure of bone development - bone age same of chronological age
• Best way to measure physical development
• Girls are slightly shorter and lighter and have a higher ratio of fat to muscle
• Developmental problems and mortality rates vary by gender and race - historically
males more likely to die than females easier to catch disease as child due to shortage
with the Y
Changes in body proportions
• Cephalocaudal trend (head to tail or upper to lower)
• Growth of the head and chest occurs before that of the trunk and legs
Babies bigger head 13% body weight than adults 2% body weight
§
• Proximodistal trend (centre to extremities)
• Growth of the arms and legs occurs before that of the hands and feet
Brain development
Neurons
• At birth, the brain is nearer its adult size than any other physical structure
• 100 to 200 billion neurons
• Synapses
• Tiny gaps between neurons
• Neurons release chemicals that send messages
• Synaptic pruning
• Unused neurons die off
• Myelination
• Neural fibres are coated with fatty insulation - myelin -speeds up
messages
• Implications for development - also influenced by genetic program and
also environmental influence
Toddlers vocab spurt due to myelin speed up process of synapes
-
Brain development
• Critical and sensitive period for brain development = late prenatal & early infancy
• Brain has great plasticity - brain can recover from injury - nerouns that havent been
commited to process can adapt to the damage neurons job
• Experience "wires" a child's brain growth - normal balanced childhood - child learn
best by play
• Under-stimulation impairs development
• Possible to overwhelm children
Video on brain plasticity
- Jody 9 year old - removed the right hemisphere - due to seizures causing brain
cognitive problems
Seizure all coming from right hemisphere - disease took over the electricity in the
brain
-
Plasticity - Left hemisphere took over the jobs of the right hemisphere - allowed
her to gain function of the left side of the body and function in a normal way
again
-
Newborn capabilities
Reflexes
• Survival reflexes - clear adapt of value
REFLEXES DEVELOPMENTAL COURSE SIGNIFICANCE
Breathing reflex Permanent Provides oxygen;
expels carbon
Eye-bink Permanent Protects from light
and foreign objects
Pupillary relex; constrict
pupils
Permanent Adapts visual system
to low illumination
Rooting reflex; turning
cheek towards tactile
(touch)
Weakens by 2 months, disappears
by 5 mo
Orients child to breast
or bottle
Sucking reflex; suck objects
placed in mouth
Modified by experience over first
few months; disappears by 7
months
Allows child to take in
nutrients
Swallowing Permanent but modified with
experience
Take in nutrients;
protects choking
• Primitive reflexes, e.g., babinski, moro, stepping
REFLEXES DEVELOPMENTAL
COURSE
SIGNIFICANCE
Babinski; Fanning then curling toes
when bottom foot stroked
Disappears 12-18
mo
Present at birth and
disappearance Indicates
normal neurological
development
Grasping; curling fingers with objects
placed in palm
Disappears 3-4 mo;
replaced with
voluntary grasp
Present at birth and
disappearance Indicates
normal neurological
development
Moro; loud noise or sudden change
in position will cause to throw arms
outward, arch back then bring arms
back
Disappearance 4
mo
Present at birth and
disappearance Indicates
normal neurological
development
Swimming; active movements of
arms and legs; hold breathe
involuntarily
Disappear 4-6 mo Present at birth and
disappearance Indicates
normal neurological
development
Stepping; feet touch will as if to walk Disappear in first 8
weeks
Present at birth and
disappearance Indicates
normal neurological
development
Newborn capabilities
Behavioural states
• Infant needs 12-13 hours of sleep per day
• Develop organised sleep/wake pattern
• Brain development is responsible for changes in sleep and wakefulness
• Gradually coincide with a night and day schedule
• Newborns have 50% REM sleep - active sleep - 6 months 30% REM - adult 20%
• Why do infants sleep so much?
• Learning and memory processes
Growth
• Endocrine system + nervous system
• Pituitary gland produces growth hormone
• Inadequate growth hormone = stunted growth
Cylica disease
-
• Treatment = synthetic growth hormone
Influences on physical growth
• Heredity largely determines height and rate of physical growth
• Catch-up growth
• Growth returning to genetic path after environmentally caused delay
• Heredity and nutrition determine weight
Nutrition
• Baby’s energy needs are twice those of an adult, relative to their size
• 25% of infant's calories are devoted to growth - impairs brain develop
• Breast- versus bottle-feeding
• A weak correlation exists between weight in infancy and obesity at older ages
But other factors as well
-
Motor development: Infants & toddlers
Motor development 0 based on developmental norms or averages
• Gross motor development
Anything involve varse muscles
○
• Crawling, standing, and walking
• Fine motor development
Specific muscles
-
• Reaching and grasping
• Motor skills go from gross to fine movements:
• Pre-reaching
• Uncoordinated, primitive
• Ulnar grasp
• Clumsy, fingers close against palm
• Pincer grasp
• Coordinated use of forefinger and thumb
Motor skills as dynamic systems
• Mastery of motor skills involves acquiring increasingly complex dynamic systems of
action
• New skills are a joint product of:
• Central nervous system development
• Movement possibilities of the body
• Environmental supports for the skill
• Motivation of the child
Baby power!
• Illustrates large variation in abilities
• 7-month-old held onto bar for 33.67 secs
• Can stand on one foot
Growth: Childhood
Body growth
• Age 2 to puberty: grow 5-7cm and 2 kg per year
• Brain development
• Lateralisation - see behaviours associated with each hemisphere
Lateralization and Handedness
• Hand preference by age 2
• Dominant cerebral hemisphere
• Responsible for skilled motor action
• Right-handed: Lefthemisphere dominant
• Left-handed: Righthemisphere or motor and language maybe divided between
hemispheres
• Leftward orientation of fetus in uterus may promote right-side postural advantage
• Left and mixed-handed
• More likely to develop better verbal and math
• Higher rates of learning disabilities
Motor development: Childhood
Motor development
• Children can modify their movements to suit the environment
• Practice is particularly beneficial for children vs. adults
Gross motor development
• Center of gravity shifts downward to the trunk, and balance improves
• Preschooler's gait becomes smooth and rhythmic
• New skills like throwing and catching balls, riding a bike, and swinging on bars
emerge
Fine motor development
• Self-Help Skills
• Gradually become self- sufficient at dressing & feeding
• Drawing and Writing
• First drawings of a person by age 3 or 4
Individual & sex differences in motor skills
• Body build, ethnicity, sex, & opportunity for physical play influence development
• African-Americans have longer limbs for better leverage in running & jumping
• Boys are slightly ahead of girls in force & power
• Girls are better in fine motor & in certain gross motor skills (hopping and
skipping)
Health & wellness in childhood
Overweight & obesity
• Increasing trend of overweight/obese children in Australia
• Overweight = 85th-95th percentile for same age/sex
• Obese = >95th percentile
• Rates have tripled in past 30 years
• Challenges associated with excess weight
• Physical - diabetes, high blood pressure, heart problems
• Psychological
Adolescence
Growth spurt
Triggered by increase in growth hormones
Height
• Girl peak rate = just under 12 years
• Boy peak rate = 13.4 years
• Weight
• Girl peak rate = 12.5 years
• Boy peak rate = 13.9 years
• Girls gain extra fat, primarily in breasts, hip & buttocks
• Boys develop broader shoulders, larger skeletal muscles, heart and lung capacity
Motor Development
• Girls' gains in gross motor are gradual & level off at 14
• Boys show dramatic spurt in strength, speed, and endurance
• Separate PE classes often begins in high school when girls and boys are no longer well
matched physically
• Athletics provide lessons in competition, assertiveness, problem solving, and
teamwork
• Regular physical activity has lifelong benefits
Puberty
• Hormonal Changes
• Growth hormone & thyroxine contribute to body size and skeletal maturation
• Estrogens and androgens present in both sexes
• Testosterone in boys leads to muscle growth, body and facial hair, and other
sex characteristics
• Estrogen & progesterone cause girl's breasts, uterus, and vagina to mature,
body takes on feminine proportions, fat accumulates, and menstrual cycle begins
Sexual maturation
• Primary sexual characteristics
XX or XY •
Ovaries/testes •
Estrogen/testosterone •
• Vagina, fallopian tubes/penis, prostate, scrotum
• Secondary sexual characteristics
• Breasts, menstrual cycle, more body fat/ facial & body hair, relatively less body
fat
Sexual maturation
• Large variation for secondary sexual characteristics
• Girls: menstruation starts between 11-15 years
• Boys: sexual maturation begins with enlargement of testes & scrotum
• What determines rate of development?
Influences on sexual maturation
• Identical twins have first menstrual cycle within a month or two, fraternal twins differ
by 12 months
• Sharp rise in body weight & fat may trigger sexual maturation in females
• Secular trend
• In industrialized nations, age of first menstruation is now younger
• Why?
• Earlier when good nutrition, long life expectancies and high literacy
rates
• Earlier in stressful environment
Early vs. late development
• Effects depend on gender and time frame
• Boys –short-term
• Early = judged to be more socially competent, attractive & self-assured BUT at
greater risk for depression, and other problem behaviours
• Late = increased risk of anxiety & depression, less sure of self,
behaviour/adjustment problems
• Girls – short term
• Early = higher levels of body dissatisfaction, socialise with older peers
associated problems
• Late = some anxiety but outperform others academically
Role of Physical Attractiveness
• Society's image of an attractive female favours the late developer
• The male image is tall, broad-shouldered, and muscular—the early developer
• Body image
• Conception and attitude toward one's physical appearance
• Early maturing girl shave less positive bodyimage
• Early maturation linked to positive body image in males; late maturation linked to
dissatisfaction with physical self
Long-term effects of maturation rate
• Effects are greatest during adolescence & gradually reduce
• Slight increase in anxiety/depression in adulthood + lower education levels for early
maturing girls
• Can be direct flow-on effects, e.g., teen pregnancy
• Outcomes may not be culturally universal
Adolescent brain
MRI studies
• Volume of the brain’s grey matter increases, peaks and then decreases throughout
the teen years
• White matter increases in a linear fashion throughout adolescence
Health
Risk behaviour
• Leading cause of death among teenagers is unintentional injury
• Road traffic crash • Violence
• Suicide
• Alcohol, drug use and cigarette smoking compromise health + lead to bad decisions
Sleep patterns
• ‘Natural’ time for falling sleep pushed back
• Melatonin rises later at night for teenagers than adults
• Insufficient sleep during adolescence need 9.2 hours per night
• Sleep-deprived adolescents are less motivated, do worse in school, more depressed,
more irritable, have worse concentration + link to obesity
Nutritional Needs
• During growth spurt, boys require 2,700 calories a day & more protein
Girls require about 2,200 calories & less protein •
Iron, calcium, riboflavin, and magnesium deficiencies are common•
• Unhealthy fad diets
The Adult
Ageing process
• Signs of ageing
• Vision
• Hearing
• Taste
• Smell
• Touch
• Skin
• Weight
• Lack of physical activity
• Gradual decline in most bodily systems
Mobility
• Muscle strength declines at a faster rate
• Athletes retain muscular physique & strength into 60s & 70s
• By 60 to 70, 10-20% of muscle power is lost
• Exercise programs enhance joint flexibility and movement
• 30-50% after 70
• Bone strength deteriorates, as does flexibility & strength of tendons, ligaments &
joints
The changing brain
Brain continuously developing •
Normal ageing = gradual and relatively mild •
degeneration with the nervous system
• Brain more likely to remain active with exercise
Female menopause
Reproductive system ages •
Menopause = ending of women’s menstrual •
periods
• Average age = 50 years
• Gradual process
• Age of menopause consistent across time & cultures
Male andropause
• Slowly decreasing level of testosterone and a variety of symptoms including:
• Low libido
• Fatigue/lack of energy
• Erectile problems
• Memory problems
• Loss of pubic hair
• By age 80, men have 20-50% of testosterone they had at age 20
• Changes are gradual and variable
Ageing vs. disease, disuse or abuse?
• What is decline really due to?
• Disease
• Osteoporosis
• Osteoarthritis
• Disuse • Abuse
Longevity Quiz
• Start with average life expectancy
• 79 years for males
• 83 years for female
• Then add & subtract years as you answer each question to arrive at an idea of your
life expectancy
Longevity Quiz
+5yearsif≥2ofyourgrandparentslivedto80yearsormore •
-4yearsifanyparent,grandparentorsiblingdiedofheartattack •
or stroke before 50
• -2yearsifanyparent,grandparentorsiblingdiedfromthese diseases after age 50 but
before 60
• -3yearsforeachcaseofdiabetes,thyroiddisorder,breast cancer, cancer of the digestive
system, asthma or chronic bronchitis among parents or grandparents
• + 4 years if you are married. If you are over age 25 and not married, -1 year for every
year not married
• +2yearsifyourfamilyincomeplacesyouinthemiddle-classor higher SES category
• -3yearsifyouhavebeenpoormostofyourlife
• -1yearforevery4.5kgyouareoverweight
• -2yearsifyourbellymeasurementisbiggerthanyourchest measurement
+3yearsifyouareover40andnotoverweight •
+ 3 years if you exercise regularly and moderately •
Longevity Quiz
• + 2 years if your regular exercise is vigorous
• -3yearsifyourjobissedentaryor+3yearsifjobisactive
• +2yearsifyouarealightdrinker(1-3drinksperday)
• -5-10yearsifyouareaheavydrinker(4+drinksperday)
• -8yearsifyousmoke2+packsperday,iflessthanthis-2years
• +2yearsifyouareapractical&reasonableperson,-2yearsif you are aggressive, intense &
competitive
+1-3yearsifbasicallyhappy&contentwithlife •
-1-5yearsifoftenunhappy,worried&feelguilty •
+1yearifyouattended4yearsofeducationbeyondhighschool •
+3yearsifyouattended5+yearsbeyondhighschool •
+4yearsifyoulivedmostofyourlifeinruralenvironment •
-2yearsiflivedmostofyourlifeinurbanenvironment •
-5yearsifyousleep>9hoursperday •
+3yearsifyouhaveregularmedical&dentalcheck-ups •
+1yearifflossyourteetheveryday •
-2yearsiffrequentlyill •
Video – 80 year-old body builder
https://www.youtube.com/watch?v=AtizBP bDmF0
(Watch first 3 minutes)
Birth bones soft and difficult to
break
Additional calcium forms stronger bones
Week 3 Lecture
Monday, 12 March 2018
1:46 PM
Overview
• Growth, motor development & health across:
• Infancy and toddlerhood
• Childhood
• Adolescence
• Adulthood
Growth: Infants & toddlers
Body Growth
• Changes in Body Size and Muscle Fat
(birth - 0 to 2 years)
• Physical growth is rapid
• Length increases 50% by first year, 75% by second
• (average 3.5kg starting weight) Weight doubles at 5 months, triples by first
year, and quadruples by second year
• Gains occur in growth spurts - 95% days are growth free
• Early rise in baby fat until 9 months - fat baby is good as they have reserve if
they're sick such as cold session
• Toddlers become more slender
Individual and group differences
• Skeletal age
• Measure of bone development - bone age same of chronological age
• Best way to measure physical development
• Girls are slightly shorter and lighter and have a higher ratio of fat to muscle
• Developmental problems and mortality rates vary by gender and race - historically
males more likely to die than females easier to catch disease as child due to shortage
with the Y
Changes in body proportions
• Cephalocaudal trend (head to tail or upper to lower)
• Growth of the head and chest occurs before that of the trunk and legs
Babies bigger head 13% body weight than adults 2% body weight
§
• Proximodistal trend (centre to extremities)
• Growth of the arms and legs occurs before that of the hands and feet
Brain development
Neurons
• At birth, the brain is nearer its adult size than any other physical structure
• 100 to 200 billion neurons
• Synapses
• Tiny gaps between neurons
• Neurons release chemicals that send messages
• Synaptic pruning
• Unused neurons die off
• Myelination
• Neural fibres are coated with fatty insulation - myelin -speeds up
messages
• Implications for development - also influenced by genetic program and
also environmental influence
Toddlers vocab spurt due to myelin speed up process of synapes
-
Brain development
• Critical and sensitive period for brain development = late prenatal & early infancy
• Brain has great plasticity - brain can recover from injury - nerouns that havent been
commited to process can adapt to the damage neurons job
• Experience "wires" a child's brain growth - normal balanced childhood - child learn
best by play
• Under-stimulation impairs development
• Possible to overwhelm children
Video on brain plasticity
- Jody 9 year old - removed the right hemisphere - due to seizures causing brain
cognitive problems
Seizure all coming from right hemisphere - disease took over the electricity in the
brain
-
Plasticity - Left hemisphere took over the jobs of the right hemisphere - allowed
her to gain function of the left side of the body and function in a normal way
again
-
Newborn capabilities
Reflexes
• Survival reflexes - clear adapt of value
REFLEXES DEVELOPMENTAL COURSE SIGNIFICANCE
Breathing reflex Permanent Provides oxygen;
expels carbon
Eye-bink Permanent Protects from light
and foreign objects
Pupillary relex; constrict
pupils
Permanent Adapts visual system
to low illumination
Rooting reflex; turning
cheek towards tactile
(touch)
Weakens by 2 months, disappears
by 5 mo
Orients child to breast
or bottle
Sucking reflex; suck objects
placed in mouth
Modified by experience over first
few months; disappears by 7
months
Allows child to take in
nutrients
Swallowing Permanent but modified with
experience
Take in nutrients;
protects choking
• Primitive reflexes, e.g., babinski, moro, stepping
REFLEXES DEVELOPMENTAL
COURSE
SIGNIFICANCE
Babinski; Fanning then curling toes
when bottom foot stroked
Disappears 12-18
mo
Present at birth and
disappearance Indicates
normal neurological
development
Grasping; curling fingers with objects
placed in palm
Disappears 3-4 mo;
replaced with
voluntary grasp
Present at birth and
disappearance Indicates
normal neurological
development
Moro; loud noise or sudden change
in position will cause to throw arms
outward, arch back then bring arms
back
Disappearance 4
mo
Present at birth and
disappearance Indicates
normal neurological
development
Swimming; active movements of
arms and legs; hold breathe
involuntarily
Disappear 4-6 mo Present at birth and
disappearance Indicates
normal neurological
development
Stepping; feet touch will as if to walk Disappear in first 8
weeks
Present at birth and
disappearance Indicates
normal neurological
development
Newborn capabilities
Behavioural states
• Infant needs 12-13 hours of sleep per day
• Develop organised sleep/wake pattern
• Brain development is responsible for changes in sleep and wakefulness
• Gradually coincide with a night and day schedule
• Newborns have 50% REM sleep - active sleep - 6 months 30% REM - adult 20%
• Why do infants sleep so much?
• Learning and memory processes
Growth
• Endocrine system + nervous system
• Pituitary gland produces growth hormone
• Inadequate growth hormone = stunted growth
Cylica disease
-
• Treatment = synthetic growth hormone
Influences on physical growth
• Heredity largely determines height and rate of physical growth
• Catch-up growth
• Growth returning to genetic path after environmentally caused delay
• Heredity and nutrition determine weight
Nutrition
• Baby’s energy needs are twice those of an adult, relative to their size
• 25% of infant's calories are devoted to growth - impairs brain develop
• Breast- versus bottle-feeding
• A weak correlation exists between weight in infancy and obesity at older ages
But other factors as well
-
Motor development: Infants & toddlers
Motor development 0 based on developmental norms or averages
• Gross motor development
Anything involve varse muscles
○
• Crawling, standing, and walking
• Fine motor development
Specific muscles
-
• Reaching and grasping
• Motor skills go from gross to fine movements:
• Pre-reaching
• Uncoordinated, primitive
• Ulnar grasp
• Clumsy, fingers close against palm
• Pincer grasp
• Coordinated use of forefinger and thumb
Motor skills as dynamic systems
• Mastery of motor skills involves acquiring increasingly complex dynamic systems of
action
• New skills are a joint product of:
• Central nervous system development
• Movement possibilities of the body
• Environmental supports for the skill
• Motivation of the child
Baby power!
• Illustrates large variation in abilities
• 7-month-old held onto bar for 33.67 secs
• Can stand on one foot
Growth: Childhood
Body growth
• Age 2 to puberty: grow 5-7cm and 2 kg per year
• Brain development
• Lateralisation - see behaviours associated with each hemisphere
Lateralization and Handedness
• Hand preference by age 2
• Dominant cerebral hemisphere
• Responsible for skilled motor action
• Right-handed: Lefthemisphere dominant
• Left-handed: Righthemisphere or motor and language maybe divided between
hemispheres
• Leftward orientation of fetus in uterus may promote right-side postural advantage
• Left and mixed-handed
• More likely to develop better verbal and math
• Higher rates of learning disabilities
Motor development: Childhood
Motor development
• Children can modify their movements to suit the environment
• Practice is particularly beneficial for children vs. adults
Gross motor development
• Center of gravity shifts downward to the trunk, and balance improves
• Preschooler's gait becomes smooth and rhythmic
• New skills like throwing and catching balls, riding a bike, and swinging on bars
emerge
Fine motor development
• Self-Help Skills
• Gradually become self- sufficient at dressing & feeding
• Drawing and Writing
• First drawings of a person by age 3 or 4
Individual & sex differences in motor skills
• Body build, ethnicity, sex, & opportunity for physical play influence development
• African-Americans have longer limbs for better leverage in running & jumping
• Boys are slightly ahead of girls in force & power
• Girls are better in fine motor & in certain gross motor skills (hopping and
skipping)
Health & wellness in childhood
Overweight & obesity
• Increasing trend of overweight/obese children in Australia
• Overweight = 85th-95th percentile for same age/sex
• Obese = >95th percentile
• Rates have tripled in past 30 years
• Challenges associated with excess weight
• Physical - diabetes, high blood pressure, heart problems
• Psychological
Adolescence
Growth spurt
Triggered by increase in growth hormones
Height
• Girl peak rate = just under 12 years
• Boy peak rate = 13.4 years
• Weight
• Girl peak rate = 12.5 years
• Boy peak rate = 13.9 years
• Girls gain extra fat, primarily in breasts, hip & buttocks
• Boys develop broader shoulders, larger skeletal muscles, heart and lung capacity
Motor Development
• Girls' gains in gross motor are gradual & level off at 14
• Boys show dramatic spurt in strength, speed, and endurance
• Separate PE classes often begins in high school when girls and boys are no longer well
matched physically
• Athletics provide lessons in competition, assertiveness, problem solving, and
teamwork
• Regular physical activity has lifelong benefits
Puberty
• Hormonal Changes
• Growth hormone & thyroxine contribute to body size and skeletal maturation
• Estrogens and androgens present in both sexes
• Testosterone in boys leads to muscle growth, body and facial hair, and other
sex characteristics
• Estrogen & progesterone cause girl's breasts, uterus, and vagina to mature,
body takes on feminine proportions, fat accumulates, and menstrual cycle begins
Sexual maturation
• Primary sexual characteristics
XX or XY •
Ovaries/testes •
Estrogen/testosterone •
• Vagina, fallopian tubes/penis, prostate, scrotum
• Secondary sexual characteristics
• Breasts, menstrual cycle, more body fat/ facial & body hair, relatively less body
fat
Sexual maturation
• Large variation for secondary sexual characteristics
• Girls: menstruation starts between 11-15 years
• Boys: sexual maturation begins with enlargement of testes & scrotum
• What determines rate of development?
Influences on sexual maturation
• Identical twins have first menstrual cycle within a month or two, fraternal twins differ
by 12 months
• Sharp rise in body weight & fat may trigger sexual maturation in females
• Secular trend
• In industrialized nations, age of first menstruation is now younger
• Why?
• Earlier when good nutrition, long life expectancies and high literacy
rates
• Earlier in stressful environment
Early vs. late development
• Effects depend on gender and time frame
• Boys –short-term
• Early = judged to be more socially competent, attractive & self-assured BUT at
greater risk for depression, and other problem behaviours
• Late = increased risk of anxiety & depression, less sure of self,
behaviour/adjustment problems
• Girls – short term
• Early = higher levels of body dissatisfaction, socialise with older peers
associated problems
• Late = some anxiety but outperform others academically
Role of Physical Attractiveness
• Society's image of an attractive female favours the late developer
• The male image is tall, broad-shouldered, and muscular—the early developer
• Body image
• Conception and attitude toward one's physical appearance
• Early maturing girl shave less positive bodyimage
• Early maturation linked to positive body image in males; late maturation linked to
dissatisfaction with physical self
Long-term effects of maturation rate
• Effects are greatest during adolescence & gradually reduce
• Slight increase in anxiety/depression in adulthood + lower education levels for early
maturing girls
• Can be direct flow-on effects, e.g., teen pregnancy
• Outcomes may not be culturally universal
Adolescent brain
MRI studies
• Volume of the brain’s grey matter increases, peaks and then decreases throughout
the teen years
• White matter increases in a linear fashion throughout adolescence
Health
Risk behaviour
• Leading cause of death among teenagers is unintentional injury
• Road traffic crash • Violence
• Suicide
• Alcohol, drug use and cigarette smoking compromise health + lead to bad decisions
Sleep patterns
• ‘Natural’ time for falling sleep pushed back
• Melatonin rises later at night for teenagers than adults
• Insufficient sleep during adolescence need 9.2 hours per night
• Sleep-deprived adolescents are less motivated, do worse in school, more depressed,
more irritable, have worse concentration + link to obesity
Nutritional Needs
• During growth spurt, boys require 2,700 calories a day & more protein
Girls require about 2,200 calories & less protein •
Iron, calcium, riboflavin, and magnesium deficiencies are common•
• Unhealthy fad diets
The Adult
Ageing process
• Signs of ageing
• Vision
• Hearing
• Taste
• Smell
• Touch
• Skin
• Weight
• Lack of physical activity
• Gradual decline in most bodily systems
Mobility
• Muscle strength declines at a faster rate
• Athletes retain muscular physique & strength into 60s & 70s
• By 60 to 70, 10-20% of muscle power is lost
• Exercise programs enhance joint flexibility and movement
• 30-50% after 70
• Bone strength deteriorates, as does flexibility & strength of tendons, ligaments &
joints
The changing brain
Brain continuously developing •
Normal ageing = gradual and relatively mild •
degeneration with the nervous system
• Brain more likely to remain active with exercise
Female menopause
Reproductive system ages •
Menopause = ending of women’s menstrual •
periods
• Average age = 50 years
• Gradual process
• Age of menopause consistent across time & cultures
Male andropause
• Slowly decreasing level of testosterone and a variety of symptoms including:
• Low libido
• Fatigue/lack of energy
• Erectile problems
• Memory problems
• Loss of pubic hair
• By age 80, men have 20-50% of testosterone they had at age 20
• Changes are gradual and variable
Ageing vs. disease, disuse or abuse?
• What is decline really due to?
• Disease
• Osteoporosis
• Osteoarthritis
• Disuse • Abuse
Longevity Quiz
• Start with average life expectancy
• 79 years for males
• 83 years for female
• Then add & subtract years as you answer each question to arrive at an idea of your
life expectancy
Longevity Quiz
+5yearsif≥2ofyourgrandparentslivedto80yearsormore •
-4yearsifanyparent,grandparentorsiblingdiedofheartattack •
or stroke before 50
• -2yearsifanyparent,grandparentorsiblingdiedfromthese diseases after age 50 but
before 60
• -3yearsforeachcaseofdiabetes,thyroiddisorder,breast cancer, cancer of the digestive
system, asthma or chronic bronchitis among parents or grandparents
• + 4 years if you are married. If you are over age 25 and not married, -1 year for every
year not married
• +2yearsifyourfamilyincomeplacesyouinthemiddle-classor higher SES category
• -3yearsifyouhavebeenpoormostofyourlife
• -1yearforevery4.5kgyouareoverweight
• -2yearsifyourbellymeasurementisbiggerthanyourchest measurement
+3yearsifyouareover40andnotoverweight •
+ 3 years if you exercise regularly and moderately •
Longevity Quiz
• + 2 years if your regular exercise is vigorous
• -3yearsifyourjobissedentaryor+3yearsifjobisactive
• +2yearsifyouarealightdrinker(1-3drinksperday)
• -5-10yearsifyouareaheavydrinker(4+drinksperday)
• -8yearsifyousmoke2+packsperday,iflessthanthis-2years
• +2yearsifyouareapractical&reasonableperson,-2yearsif you are aggressive, intense &
competitive
+1-3yearsifbasicallyhappy&contentwithlife •
-1-5yearsifoftenunhappy,worried&feelguilty •
+1yearifyouattended4yearsofeducationbeyondhighschool •
+3yearsifyouattended5+yearsbeyondhighschool •
+4yearsifyoulivedmostofyourlifeinruralenvironment •
-2yearsiflivedmostofyourlifeinurbanenvironment •
-5yearsifyousleep>9hoursperday •
+3yearsifyouhaveregularmedical&dentalcheck-ups •
+1yearifflossyourteetheveryday •
-2yearsiffrequentlyill •
Video – 80 year-old body builder
https://www.youtube.com/watch?v=AtizBP bDmF0
(Watch first 3 minutes)
Birth bones soft and difficult to
break
Additional calcium forms stronger bones
Week 3 Lecture
Monday, 12 March 2018 1:46 PM
Document Summary
Overview: growth, motor development & health across, infancy and toddlerhood, childhood, adolescence, adulthood. Birth bones soft an e if ally tage ft and difficult to. Changes in body proportions: cephalocaudal trend (head to tail or upper to lower, growth of the head and chest occurs before that of the trunk and legs. Babies bigger head 13% body weight than adults 2% body weight: proximodistal trend (centre to extremities, growth of the arms and legs occurs before that of the hands and feet. Toddlers vocab spurt due to myelin speed up process of synapes ft and difficult to forms stronger bones and cy. Toddlers vocab spurt due to myelin speed up process of synapes. Jody 9 year old - removed the right hemisphere - due to seizures causing brain cognitive problems. Seizure all coming from right hemisphere - disease took over the electricity in th brain.
