Infant Development (Physical)

Physical Devt

patterns of growth

cephalocaudal & proximodistal

head

constitutes as large portion of the body

cephalocaudal pattern

fastest growth is from the top (head) to bottom

proximodistal pattern

growth starts at the center of the body and moves towards extremities

average newborn length and weight (North America)

20 inches & 7 1/2 lbs

lost body weight in most newborns

5% to 7%

by the age of 4 months

newborns double their weight

vy their bday (1yr)

weight triples

second year

growth slows; ave. 32

lobes

4 major areas of brain hemisphere cortex

frontal lobes

involved in voluntary movement, thinking, personality. intentionality or purpose

occipital lobes

function in vision

temporal lobes

have active role in hearing, language processing, and memory

parietal lobes

registering spatial location, attention, and motor control

neurons

process information

axon

sends electrical signals away from central part of neuron

synapses

gaps between axons

dendrites

communicates with other neurons (passes signals)

neurotransmitters

chemical substances released in synapse communication

Brain development

occurs extensively during prenatal period

shaken baby syndrome

brain swelling and hemorrhaging

[early experience] deprived environment

may cause depressed brain activity

[early experience] brain

demonstrates flexibility and resilience

[early experience] repeated experience

wires the brain

[early experience] connections

infant's brain wait for experiences to determine how this is made

[early experience] wiring patterns

mainly directed by genes before birth

[early experience] experiences of sights, smells, sounds, touches, language, and eye contact

help shape neural connections after birth

2 key developments during 1st 2yrs

myelin sheath, connections between dendrites

myelination

process of encasing axons with myelin sheath; begins prenatally and continues after birth

myelination (function)

increases speed of processing information

course of myelination

occurs after birth; completed in 1st 6months

course of auditory myelination

not completed until 4 or 5 yrs of age

extensive changes in frontal lobe myelination

during adolescence

major brain changes at 2yrs old

increases in synaptic connections with synaptic "blooming and pruning"

[changing structures] hemispheres

begin to specialize at birth

[changing structures] brain

areas do not mature uniformly

[changing structures] course of spurt in EEG

occurs 1 ½ to 2 years of age

[changing structures] course of spurts

occurs at 9, 12, 15, and 20 yrs of age

[changing structures] spurts

in brain activity, coincide with important cognitive development changes

sleep

restores, replenishes, and rebuilds brain and bodies; lets neurons shut down and repair themselves

newborns sleep

16 to 17 hrs a day

infant sleep

times and patterns for sleeping vary

cultural variation

influence sleeping patterns

[sleep cycle] 1 month

begin to sleep longer at night (american infants)

[sleep cycle] 4 months

closer to adult

REM Sleep

eyes flutter beneath closed lids

Non-REM Sleep

fluttering eye movement does not occur ad sleep is more quiet

1/2 of infant's sleep

made up of REM Sleep

REM Sleep (function)

promote brain development in infancy; large amounts provide added self

infant (3mos)

40% REM; REM no longer begins their sleep cycle

ideal shared sleeping

crib next to parent's bed

concerns of shared sleeping

quicker response to cries, help detect breathing pauses, bed sharing risks rolling over baby

sudden infant death syndrome (SIDS)

infant stops breathing and dies instantly without apparent cause

course of SIDS

2 to 4 months of age

[SID] sleeping with pacifier

SIDS less likely

[SID] low birth weight

SIDS more likely

[SID] african american & eskimo

SIDS more likely

[SID] lower socio economic groups

SIDS more likely

[SID] soft bedding

SIDS more likely

[SID] abnormal brainstem functioning

SIDS more likely

[SID] has siblings who have died of SID

SIDS more likely

sleep apnea

temporary cessation of breathing; airway is completely blocked

breast fed infants

lower rates of weight gain than bottle fed

breast feeding

reduces risk of obesity

age when milk is main source of nutrients and energy

age 4 to 6 months

benefits of breast feeding (in first 2yrs)

appropriate weight gain & fewer allergies, more advanced neurobio and cognitive devt, advanced language & motor devt, better visual acuity

breast feeding prevents

diarrhea, respiratory infections, bacterial urinary tract infection (UTI), otitis media (middle ear infection)

breastfeeding promotes

denser bones, reduced cancer in child and mother

forms of severe malnutrition

marasmus & kwashiorkor

marasmus

sever malnutrition due to insufficient caloric intake; shrunken, wasted, elderly appearance

kwashiorkor

severe malnutrition caused by protein deficiency; child's abdomen and feet swell with water