Chapter 8 - Physical Development in Early Childhood Flashcards Preview

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Flashcards in Chapter 8 - Physical Development in Early Childhood Deck (54)
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Brain Development

At age 2, the brain is 70% of its adult weight
At age 6, it’s 90% of its adult weight
Throughout this time, we see improvements in physical coordination, perception, attention, memory, language, logical thinking, imagination…
It’s not just the size of the brain that changes
By age 4, many parts of the cortex have overproduced synapses
Some regions, like the frontal lobes, have double the eventual adult number
Myelination of neural fibres, as well as synaptic growth, result in a high energy need that causes the energy metabolism in the cerebral cortex to peak at about this time
Pre-frontal cortex has rapid growth
Left hemisphere more active during 3 to 6 years
Right hemisphere increases steady with slight sprit between 8 and 10
Different parts of the brain grow more rapidly at different times
This biological development coincides with increases in abilities



Dew to brain lateralization (nature and nurture)
Prenatal thumb sucking and infants smoother movement with right side might explain why most children from a right hand bias
Left-handed people more often have right-brain or mixed dominance for language than do right-handed people
Inherit a handed bias but experience can over right it
Left handedness is more often seen in mentally retarted and mentally ill dew to atypical lateralization
Unusual lateralization can have advantages –speech, flexible thinking, more likely to form verbal and mathematical talents



Overabundance of synapses allow for young brain to acquire certain skills and ability’s
As neurons are stimulated they become more elaborate and to make room the unstimulated ones lose connection fibers and thus synapses
By 8 to 10 cognitive functions are no longer widely distributed and becomes more localized


Body growth

• After the first two years growth tapers off to a slower growth pattern.
• Baby fat drops off and they become thinner
• Torso lengthens and widens
• Spine straightens
• Longer legs
• Posture and coordination improves
• Extremely slow growth compared to ethnical average is a cause for concern
• Between 2 and 6 45 new epiphyses emerge
• By the end of preschool children start to loose primary teeth (genetic factors, cultural ancestry, nutritional factors, primary tooth care, tobacco smoke)



Special growth centers at the ends of a long bones that fuses with the shaft of the bone at the point where it was previously separated by cartilage to allow bone growth.


Skeletal age

The "bone age" of a child is the average age at which children reach this stage of bone maturation. A child's current height and bone age can be used to predict adult height.
Measured by x-rays of growth centers (Epiphyses)
It is the best estimate of a child’s physical age.
There is a gap in boys and girls at birth by 4 to 6 weeks and the gap widens through infancy and childhood. This may contribute to girl’s greater resistance to harmful environmental influence.


Cerebellum Development

Cerebellum is a brain structure that aids in balance and control of body movement

• Fibres linking the cerebellum to the cerebral cortex grow and myelinate from birth through the preschool years
• This contributes to dramatic gains in motor coordination
• These connections also support thinking—children with damage to the cerebellum usually display both motor and cognitive deficits, including problems with memory, planning, and language


Reticular formation Development

Reticular formation is a brain structure that maintains alertness and consciousness

• This structure generates synapses and myelinates throughout early childhood and into adolescence
• Some of fibres sent out from the reticular formation go to the frontal lobes of the cerebral cortex, contributing to improvements in sustained, controlled attention


Hippocampus Development

and in spatial images we use to help us find our way

• This structure undergoes rapid synaptogenesis and myelination in the second half of the first year
• Over the preschool and elementary school years, the hippocampus and surrounding areas of the cerebral cortex continue to develop quickly, establishing connections with one another and with the frontal lobes
• We thus see dramatic gains in memory and spatial understanding in early and middle childhood
• Autobiographical memory – infantile amnesia


Corpus callosum Development

Corpus callosum is the large bundle of fibres connecting the two hemispheres of the brain

• Synaptogenesis and myelination increase at 1 year, peak between 3 and 6, then continue at a slower pace through middle childhood and adolescence
• The corpus callosum supports
 - Smooth coordination of movements on both sides of the body
 - Integration of many aspects of thinking, including perception, attention, memory, language, and problem solving



Amygdala – plays a central role in processing emotional information
Connections from between the amygdala and prefrontal cortex form and mylaniate during childhood and adolescence


Physical growth is influenced by a complex combination of ___________ and ____________ factors

Physical growth is influenced by a complex combination of genetic and environmental factors


Heredity and Hormones

Children’s physical size and rate of growth are related to those of their parents
Genes influence the body’s production of hormones, which in turn influences growth


Pituitary gland

a gland located near the base of the brain that releases hormones affecting physical growth


Growth hormone (GH)

Growth hormone (GH) is a pituitary hormone that affects the development of all body tissues except the central nervous system and the genitals
• Children who lack GH reach an average mature height of only 4’4”
• When treated with early injections of GH, they show catch-up growth, and then grow at a normal rate


Short height not do to (GH) problems and the effects on self esteem

No deficit in self-esteem or any other messure of psychological adjustment


Thyroid-stimulating hormone (TSH)

Thyroid-stimulating hormone (TSH) is a pituitary hormone that stimulates the thyroid gland to release thyroxine, which is necessary for normal brain development and body growth
• Without sufficient thyroxine, GH doesn’t have its full impact on body size
• Infants born with a thyroxine deficiency will show deficits in growth of both brain and body if they don’t receive immediate treatment
 - After the brain growth spurt, only physical growth is a concern here


Emotional Well-Being

Emotional well-being can have strong effects on growth and health
Preschoolers with very stressful home lives suffer more respiratory and intestinal illnesses as well as more unintentional injuries


Psychosocial dwarfism

A growth disorder that appears between age 2 and 15. Typical chararictistics include decreased GH secretion (do to stress, emotional deprivation), very short stature, immature skeletal age, and serious adjustment problems.
If removed from environment early then GH returns to normal and they exhibit fast growth. If not the dwarfism can be permanent.


Sleep Habits and Problems

GH is released during sleeping hours
Sufficient rest contributes to a child’s ability to play, learn, and contribute positively to family functioning
Sleep difficulties are associated with: impaired cognitive performance, decreased attention, speed of thinking, working memory, test scores. More pronounced in low SES perhaps it heightens impact of other environmental stressors.
Disrupts parents sleep which could cause family stress.


Changes in amount of sleep

Total sleep general declines in early childhood
2- and 3-year-olds sleep 11 to 12 hours
4- to 6-year-olds sleep 10 to 11 hours
Younger preschoolers typically take a 1- to 2-hour nap in early afternoon, though there’s considerable variability


Going to sleep

Preschoolers can be rigid about their bedtime rituals, which may help them feel less uneasy about being left alone in a dark room
Trouble falling asleep is common in early childhood
It’s often more intense when families are in turmoil


Problems with sleep

It’s common for children to wake up during the night from time to time
Those who can’t get back to sleep may suffer from a sleep disorder

Nightmares are common at this age—about ½ of 3- to 6-year-olds have them occasionally (trouble separating fantasy and reality)
• About 4% of children are frequently sleepwalkers
• About 3% suffer sleep terrors (genetic and/or stress or extreme fatigue)

Most children who suffer from sleep disorders grow out of them naturall



Appetite becomes unpredictable in early childhood
• There’s often an overall decrease, as growth has slowed
• There’s a tendency to eat a lot at some meals and little at others
• Children often become picky eaters at this age


Types of foods

Preschoolers require the same foods as adults, though obviously in lower amounts
Fats, oils, and salt should be kept to a minimum because of the link to high blood pressure and heart disease later
Foods high in sugar should be avoided


food preferences

Pickyness is adaptive
Young children’s food preferences are shaped in part by the environment
They’ll eat what parents or admired peers eat
Repeated, unpressured exposure to new food increases acceptance
Beware adding sugar or salt to a new food
Beware sweet drinks it can cause milk avoidance
milk avoidance children are smaller and have less bone density


encourage healthy eating

A positive emotional climate at mealtime can be important
Although it’s important to encourage healthy eating, too much worrying and controlling behaviour surrounding food can have adverse effects
• For instance, bribing children to eat their vegetables by giving cookies afterwards can actually decrease their liking of vegetables and increase their liking of cookies
• It’s also important to give children opportunities to learn self-control, which may not happen if too much adult control is exerted


diets may be lacking

Even if there’s enough food, their diets may be lacking in protein, or in
Iron, which prevents anemia
• Calcium, which supports development of bones and teeth
• Zinc, which supports immune system functioning, neural communication, and cell duplication
• Vitamin A, to help maintain eyes, skin, and a variety of internal organs
• Vitamin C, to facilitate iron absorption and wound healing


Many North American children lack sufficient ______-________ food

Many North American children lack sufficient high-quality food


A child who lacks adequate nutrition may well

• Be smaller than a well-nourished child
• Have attentional difficulties
• Score lower on mental tests
• Show behavioural problems, especially hyperactivity and aggression