Module TwoModule Two Growth and Health Growth and Health

Chapter 4 OBJECTIVES:How do children grow physically?What can disrupt physical growth?

How does the brain grow during this time?

Did you know that humans Did you know that humans take the longer to become take the longer to become physically mature than any physically mature than any

other animal?other animal?

We spend about 20% of our lives growing physically!

Physical GrowthPhysical Growth

The most obvious way to measure physical growth is in terms of sheer size

‐ The averages of height and weight are used as a general measure

Example: ‐ Between birth and two, average height

increases from 19 to 32 inches and the average weight increases from 7 to 22 pounds

Growth is very rapid in infancy and adolescence

An interesting rule of thumb An interesting rule of thumb is that boys achieve half of is that boys achieve half of their adult height by age 2 their adult height by age 2

and girls at 18 months.and girls at 18 months.

Weight GainWeight GainA layer of fat appears under the skin near the end of the prenatal period this helps the fetus and the infant regulate body temperature, this continues to accumulate rapidly during the first year producing what we call “baby fat”.

Infants typically double their birth weight by the fourth month , triple it by the end of the first year and more than quadruple it by 2 years.

During the preschool years, children actually become leaner, but in the elementary school years they begin to acquire more fat

Physical Changes Physical Changes As children go through growth spurts, body parts develop at different rates, which means that infants and young children are not simply scaled down versions of adults.

‐ The head and trunk grow faster than the legs, making them look top heavy compared to older children and adolescents.

The legs and feet will catch up later in childhood and their bodies take on proportions that are more adult like.

When does the most When does the most development occur?development occur?

Today, children and adults are Today, children and adults are taller and heavier than taller and heavier than

previous generations, due previous generations, due largely to improved health and largely to improved health and

nutritionnutrition

These changes from one generation to another are known as Secular Growth Trends

Not only does the concept of Not only does the concept of “average” growth and “average” growth and development vary by development vary by

generation, but also by nation.generation, but also by nation.

“Average” and “normal” are not the same. This applies not only to physical development, but to

all aspects of development

Shhh…Baby’s Sleeping!Shhh…Baby’s Sleeping!

Does SLEEP impact Does SLEEP impact development?development?

It is often taken for granted how much influence sleep has on growth. Sleep is

essential for normal growth because 80% of the growth hormone is secreted while children and adolescents sleep (Smock,

1998).

Does sleep effect growth?Does sleep effect growth?The growth hormone is secreted during sleep by the pituitary gland in the brain, which triggers the hormone somatomedin

‐ This hormone causes the bones and muscles to grow

In the last module we discussed how much time infants spend sleeping and that as children grow older the time spent in sleep decreases.

‐ From roughly 12 hours at age 3 ‐ 10 hours at age 7‐ 8 hours at age 12

Sleep….Sleep….Sleep also effects the cognitive processes and a child’s adjustment to school.

Children who do not sleep well (waking frequently or lack consistent sleep nightly) are often unable to pay attention in school (Sadeh et al., 2002).

‐ Children with poor sleeping habits are also more likely to disregard teachers’ requests and act aggressively

Establishing a bedtime routine will allow the child to “wind down” and will be more likely to get a restful night’s sleep.

NutritionNutrition

The fuel for growth comes from the foods children eat. Nutrition is particularly important during infancy when physical growth is so rapid.

Because growth requires so much energy, young babies must consume an enormous amount of calories in relation to their body weight.

What’s the best food for What’s the best food for babies?babies?

Breast versus bottle feeding

The breast is bestThe breast is bestBreast-feeding ensures that babies get the nourishment that they need.

Human milk contains the proper amounts of carbohydrates, protein, vitamins and minerals for babies.

Breast feeding also has several advantages over bottle feeding (Shelov, 1993).

Breast is BestBreast is BestBreast-fed babies are ill less often than bottle-fed babies because breast milk contains antibodies that kill bacteria and viruses.

‐ Breast milk is always sterile and at body temperature.

Breast–fed babies are less prone to diarrhea and constipation because breast milk is easier to digest.

Breast-fed babies adjust more rapidly to solid foods because changes in the milk’s taste reflects the mother’s diet (Kail, 2004).

The many benefits of breast-The many benefits of breast-feeding do NOT mean that feeding do NOT mean that bottle-feeding is harmfulbottle-feeding is harmful

Formula, when prepared in sanitary conditions can generally

provide the same benefits as breast milk

While nutritionally formula can While nutritionally formula can be just as good as breast milk, be just as good as breast milk, it does not protect infants from it does not protect infants from disease and infants are often disease and infants are often

prone to develop allergies prone to develop allergies from formula.from formula.

BUT bottle-feeding does have BUT bottle-feeding does have advantages!advantages!

Mothers and family members can still participate in the intimacy of feeding the baby.

Long-term longitudinal studies find that breast-fed and bottle-fed babies are similar in physical and psychological development (Fergusson, 1987).

Today, women in industrialized countries can chose either method knowing that the infant’s dietary needs are met.

Older childrenOlder childrenChildren need a varying number of calories over the preschool, elementary school and adolescence to continue to grow and develop.

More important than the number of calories is a healthy, balanced diet that provides all of the five major food groups.

A healthy diet not only draws on the major food groups, but also avoids too much sugar and too much fat.

Dramatic changes occur Dramatic changes occur physically in infancy and early physically in infancy and early childhood. After a period of childhood. After a period of the body relative dormancy the body relative dormancy

another transformation another transformation begins.begins.

Adolescence begins officially Adolescence begins officially with with puberty, puberty, which refers to which refers to the adolescent growth spurt the adolescent growth spurt

and sexual maturation.and sexual maturation.

Hello Puberty!Hello Puberty!

Sexual maturation includes a change in primary sex primary sex characteristicscharacteristics, which refers to the organs directly involved in reproduction.

‐ Girls: Ovaries, uterus and vagina

‐ Boys: scrotum, testes and penis

Physical changes in pubertyPhysical changes in puberty

The development of secondary sex characteristics, which are physical signs of maturity not directly linked to the reproductive organs.

These are the changes the distinguish a man from a woman

Which is a Boy or a Girl?Which is a Boy or a Girl?How do you know?How do you know?

You don’t necessarily know You don’t necessarily know at that age, right?at that age, right?

Think on your own…What are the common ways to tell

the gender of a small child?

Try it again…Try it again…Which is the Boy or the Which is the Boy or the

Girl?Girl?

This one should have been This one should have been EASYEASY for you to answer. for you to answer.

But why? But why?

Puberty produces changes in physical appearance that make it easy to

distinguish a boy from a girl- secondary sex characteristics!

We’ve all experienced them…what are they?

Secondary Sex Secondary Sex CharacteristicsCharacteristics

‐ Girls- Breast development, widening of the pelvis, Menarche (menstruation), voice changes.

‐ Boys- Spermarche, voice deepens, shoulders broaden, facial hair

The development of facial and body/pubic hair occur for both genders.

This transformation of puberty This transformation of puberty can lead to awkward social can lead to awkward social

interactions during the initial interactions during the initial spurt as girls are often taller spurt as girls are often taller

and more mature-looking than and more mature-looking than boys.boys.

Girls are particularly likely to be dissatisfied with their appearance and

feel awkward or self-conscious

Effects of PubertyEffects of PubertyResearch has shown that early maturation can be harmful for girls.

Girls who mature early often lack self-confidence, are less popular, are more likely to be depressed and have behavior problems.

These potential problems can be offset by several factors, including a supportive family.