pp05 physical development in infancy

Feldman Child Development 4/e ©2006 Prentice Hall

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Chapter 5

Physical Development in Infancy (birth to age 2)

Additions made by Assoc. Prof.Dr. Senija

Tahirović

Child Development, 4/e by Robert Feldman

Created by Bratsch & 4e update by Klamon-Miller


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Content of lecture

How do the human body and nervous system develop?

What developmental tasks must infants undertake in this period?

What is the role of nutrition in physical development?

What sensory capabilities do infants possess?


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Physical GrowthThe average newborn weighs around 3200

grams.By 5 months, the average infant’s birth weight

has doubled to around 6 400 grams.By the first birthday, the infant’s weight has

tripled to around 9 600 grams.By the end of the second year, the child’s

weight has quadrupled since birth.


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Physical Growth


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Principles of Growth Cephalocaudal principle states that growth follows a

pattern that starts with the head and upper body then proceeds to the rest of the body

Proximodistal principle states that growth proceeds from the center of the body outward

Principle of hierarchical integration states that simple skills typically develop separately and independently

Principle of the independence of systems suggests that different body systems grow at different rates


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Principles of Growth

At birth, the head represents one-fourth of the neonate’s body. By adulthood, the head is only one eighth the size of the body.


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Nervous System and the BrainNeurons are the basic cells of the nervous system.

Synapses are the gaps between neurons through which communication occurs.

Myelin is the fatty substance that acts like insulation to assist speed of neural impulses.

Cerebral cortex is the upper layer of the brain.

Plasticity refers to the degree that a developing structure or behavior is modifiable due to experience.


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The basic element of the nervous system, the

neuron is composed of a number of components.


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Nervous System and the Brain

Over the first two years of life, networks of neurons become increasingly complex and interconnected.


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Integrating Bodily Systems: Life Cycles of Infancy

The most basic activities of newborns are infant’s body rhythms

- awakening, - eating,- sleeping and- going to the bathroom.

They govern the infant behavior , often in random times.


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One of the major body rhythms is that of an infant’s stage , the degree of awareness it display to both internal and external stimulation

Awake states includes behaviors as:

Alertness (awareness)Nonalert wakingFussing ( protest)Crying

Transition states between sleep and awakingsleepiness - ifant eyes opening and closing slowely, low level of motor activityDaze- state occurs berween episodes of alert and sleepiness. Low level of activitySleep-wake transition – behaviour of both wakefulness and sleep are evident


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Sleep states last between 16 to 17 hours day

Active sleep – eyes closed, smiles, grimaces, sucking, This period of active sleep is similar but not indetical to REM (rapid eye movement)

REM -rapid eye movement sleep is period of sleep that is found in older children and adults and is associated with dreaming

Quiet sleep – eyes are closed, respiration slow and regular, motor activities limited

Transitional sleep stateActive-quiet transition sleep is period occures between period of

active sleep and quiet sleep – eyes are closed, little motor activity


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Sudden Infant Death Syndrome (SIDS)

Cause of SIDS is unknown.1 in 1,000 infants die a year in the U.S. from

SIDS.No means to prevent SIDS have been found.Risk factors may include boys, low birth

weight, low APGAR scores, a mother who smokes or uses drags during pregnancy, possible brain defect


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Sudden Infant Death Syndrome (SIDS)

SIDS strikes about 1 in 1,000 infants in the United States each year. Although it seems to occur when the normal patterns of breathing during sleep are interrupted, scientists have been unable to discover why that might happen. It is clear that infants don’t smother or choke; they die a peaceful death, simply stopping to breathe. In the United States, SIDS rates have dropped dramatically as parents have become more informed and put babies to sleep on their backs instead of on their stomachs.


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Motor Development in Infancy Reflexes are the unlearned, organized, involuntary responses that occur

automatically in the presence of certain stimuli

• Rooting reflex: turning head toward things that touch the cheek• Stepping reflex: legs move in a stepping fashion when held upright

with feet on the floor• Swimming reflex: paddle and kick motion while on belly• Moro reflex: activated when support for head removed; arms thrust

out and appear to grasp• Babinski reflex: fanning the toes when outside of foot is stroke• Eye-blink reflex: rapid opening and closing of eyes to direct light

exposure• Sucking reflex: tendency to suck things that touch the lips


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Reflexes – unlearned, organized, involuntary responses that occur automatically in the presence of certain stimuli


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Milestones of Motor Development in Infancy Obvious physical changes in infancy

Gross motor skills – scooting on the floor, crawling, walking, sitting up

Fine motor skills – coordinate movement of extremity, reach and grasp objects, pick up small objects


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Developmental Norms, Comparing individuals with the group

Norms represent the average performance of a large sample of children of a given age.

One of most widely used technicues to determinate infant’s normative standards is the Brazelton Neonatal Behavior Assessment Scale (NBAS) – a measure used to determine infants’ neurological and behavioral responses to the environment.

It includes 27 seperate categories of responses that continue for general aspects

1. Interaction with others

2. Motor behavior

3. Physiological control

4. Responses to the stress


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Developmental Norms, Comparing individuals with the group

To be effective, norms need to be based on large, heterogeneous, culturally diverse samples of children.

When comparing child ability with norms do interpret it carefully, why?


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Nutrition in Infancy Malnutrition is a condition of having improper amount and balance

of nutrients; results of development could be slower growth, lower IQ scores, poor school performance.

Marasmus is a disease characterized by ending of growth as a result of malnutrition.

Kwashiorkor occurs in older, skinny children and is characterized by swelling of the stomach limbs and face with water. The body is struggling to make use of the few nutrients it has available.

Nonorganic failure is a disorder in which infants stop growing due to lack of stimulation and attention as a result of inadequate parenting. This has an emotional cause.

Obesity is defined as weight greater than 20% above average; effects of obesity in infants is not quite clear yet.


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Breast Feeding vs. Bottle Feeding


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Breast Feeding vs. Bottle Feeding

Breast milk contains all the nutrients necessary for growth and offers immunity to various childhood diseases.

Breast feeding offers emotional advantages to mother and child and may cause decreased risk of breast cancers to the mother.

Social patterns of breast feeding


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Development of the Senses

Sensation is the stimulation of the sense organs.

Perception is the sorting out, interpretation, analysis, and integration of stimuli involving the sense organs and the brain.


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Visual PerceptionNewborn’s vision ranges from 20/200 to

20/600, meaning they cannot distinguish beyond 20 cm. which is one-tenth to one –third that of average adults.

By 6 months, the average infant has 20/20 vision – identical to that of adults.

Binocular vision is achieved by 14 weeks.Infants show clear visual preferences from

birth.


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Auditory Perception• Hearing begins prenatally.• Infants are born with preference to certain sound

combinations.• Sound localization, the ability to determine where

a sound is coming from, is at adult level by 1 year old.

• By four and a half months, infants can discriminate their own names.


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Smell and TasteSense of smell is extremely well developed

in infants. A 12- to 18-day-old infant can distinguish the smell of the mother.

Taste is also well developed in infants who can distinguish disgust and show preference for sweet.

Infants also develop taste preferences depending on what the mother drank while they were in the womb.


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Sensitivity to Pain and Touch• Infants are born with the capacity to experience pain.

Pain produces signs of distress such as increased heartbeat, sweating, facial expressions, and changes in intensity and tone of crying.

• Touch is one of the most highly developed sensory systems of the newborn and one of the first to develop. Being touched promotes growth and emotional development. Infants reaching out to touch assists in exploring the world.


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Sensitivity to Pain and Touch


Questions for review

1. What developmental tasks in physical development must infants undertake in this period.

2. What is the role of nutrition in physical development?

3. Explain Development of the Senses in infancy in

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pp05 physical development in infancy

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