5. Physical Dv't in Infants & Toddlers Flashcards
Cephalocaudal principle
Children start out with large head-to-body proportions. As they grow up, the proportions change.
How does muscle develop in early childhood?
- all muscles are present at birth
- they become longer and thicker
- this accelerates during adolescence
How does fat develop in early childhood?
- accumulates rapidly in the first year
- become leaner in pre-school years
- acquire more fat in early elementary, accelerating during adolescence
How does bone develop in early childhood?
- begin to form prenatally.
- start as cartilage, then harden in middle, ends, then between
epiphyses
the ends of the cartilage structures that turn into bone
secular growth trends
changes in physical development between generations that are related to environmental factors
describe the difference between average and normal growth
the normal range is much wider than the average
3 factors affecting physical growth
- heredity
- hormones
- nutrition
hormones
chemicals that are released by glands and travel in blood streams to act on other areas of the body
what is the role of the pituitary gland
- produces growth hormones (GH)
- usually during sleep, but sometimes after exercise
- triggers the liver to release a hormone that causes muscle and bone growth
thyroxine
a hormone released by the thyroid gland that is essential for nerve-cell development
why do babies require a lot of calories
growth takes a LOT of energy, and is very rapid in infancy
why is bottle-feeding dangerous in developing nations?
- contaminated water, causing illness
- malnutrition from using less formula to save cost
what changes at age two regarding nutrition?
- growth slows, so does appetite
- pickiness - eating only familiar foods can be adaptive
advantages of breastfeeding
- ensures babies get proper nutrition
- proper balance of carbs, fats, protein, vitamins, minerals
- mom’s antibodies
- less indigestion
- change to solids more easily (used to changing flavours)
- not contaminated
advantages of bottle-feeding
- formula still gives the baby what they need
- dad can help and connect with baby
- no long-term differences in physical/psychological development
malnourished
Lacking adequate nutrition. Indicated by small size for age.
how does malnutrition affect development
- no affect on physical development in the end
- malnourished-as-infants lower intelligence scores
- trouble maintaining attention
3 things necessary to prevent malnutrition
- food availability
- nutrition education
- behavioural change (nurturing engagement)
What is IMCI
Integrated Management of Childhood Illness
- combats the 5 biggest causes of childhood death
1. training health care professionals
2. improving health care systems
3. changing family/community practices
highest cause of death after the first year
accidents
5 biggest causes of infancy death
pneumonia malaria diarrhea malnutrition measles
neuron
a cell in the nervous system that specializes in transmitting information
neuronal cell body
a structure at the centre of a neuron containing biological mechanisms for maintaining cellular life.
dendrite
the receiving end of the neuron; branch-like
axon
the sending end of the neuron; tube-shaped
transmits message from the dendrites to other cells
myelin
a fatty sheath that insulates the axon and allows it to send messages faster
terminal buttons
structures at the end of axons that release neurotransmitters
neurotransmitters
chemicals in the terminal buttons that carry information to nearby dendrites
synapse
the gap between one neuron’s axon and the other neuron’s dendrite.
cerebral cortex
- outer later of the brain
- 10 billion neurons
- many of the functions we think of as human
cerebral hemispheres
the right and left halves of the cerebral cortex
corpus callosum
a thick bundle of axons that link the right and left hemispheres of the cerebral cortex
frontal cortex
an area of the brain that is responsible for planful activities and personality
what is the left cortex responsible for?
- produce and understand language
- reason
- compute
what is the right cortex responsible for?
- artistic and musical abilities
- perception of spatial relationships
- ability to recognize faces and emotions
neural plate
a group of cells that form about 3 weeks after conception that develops into the neural tube, brain, and spinal cord
brain development
- 3 weeks - neural plate
- 4 weeks - plate forms tube
- 10 weeks - ends fuse, neurons produce at one end
- 28 weeks - all neurons produced that ever will be
- 4 months - myelin
- 7 months - all neurons in their final places
how fast do neurons grow during development
4000 per second
myelin development
starts at 4 months and continues into adolescence
- seen in improved coordination and reaction time
how does the brain grow after birth
- no new neurons
- axons lengthen
- dendrites branch and grow
- many new connections (synapses)
synaptic pruning
a period in infancy (and adolescence) when the synapses begin to disappear as the brain weeds out unnecessary or underutilized connection between neurons
EEG
- electroencephalogram
- an electrical measurement of brain waves
fMRI
- functional magnetic resonance imaging
- measures the flow of blood in the brain using magnetic fields
PET scan
- positron emmission tomography
- traces radioactive glucose uptake in the brain
fNIRS
- functional near infrared spectroscopy
- measures flow of blood in the brain
- less invasive than fMRI
- silent (good for auditory stimuli)
- easier to use with infants
describe hemispheric specialization at birth
already begun; happens early
- e.g. left hemisphere already specialized for language, so language development happens more rapidly
- some specialization happens more slowly - e.g. facial recognition by preschool years
describe the frontal cortex
- regulates intentional behaviour and feelings - happiness, sadness, fear
- LFC regulates infants’ tendency to approach/explore
- RFC regulates tendency to avoid or escape
left hemisphere
language processing
right hemisphere
recognizing non-speech sounds, emotions, faces
neuroplasticity
the extent to which brain organization is flexible
motor skills
coordinated movements of the limbs and muscles - ex. crawling
locomotion
moving around the world - crawl, stand, walk
opposable thumb - purpose
grasp and manipulate objects
fine-motor skills
activities that involve small muscle groups - grasping, holding, manipulating objects
gross-motor skills
activities requiring large muscle groups - running, throwing, jumping
reflexes
unlearned responses that are triggered by a specific form of stimulation
Babinski reflex
reflex where a babies toes fan out when the sole is stroked heel to toe
- unknown purpose
Blink reflex
baby’s eyes close in response to light or noise
- protect senses
Moro reflex
baby throws its arms out, then in when head falls or loud noise
- helps cling to mother
Palmar reflex
baby grasps an object placed in hand
- precursor to walking??
Rooting reflex
baby turns head and opens mouth when cheek stroked
- helps find nipple
Stepping reflex
baby ‘steps’ legs when held upright
- precursor to walking
Sucking reflex
sucks when object placed in mouth
- permits feeding
Withdrawal reflex
withdraws foot when pricked with pin
- protection from pain
When can babies usually sit with support?
4 months
When can babies usually sit unassisted?
7 months
When can babies usually stand while holding on?
9 months
When can babies usually pull to stand?
12 months
When can babies usually climb stairs?
13 months
When can babies usually stand alone briefly and walk with assistance?
14 months
When can babies usually walk alone?
15 months
What things affect motor development?
- muscle development
- neural development
- massage
- medical complications, surgery
- seasons in moderate climates (not extreme - Edmonton)
dynamic systems theory
motor development involves many distinct skills, organized and reorganized over time to meet task-specific demands
What elements need to be in place for locomotion?
- practice
- visual system - balance, judging surfaces suitable for walking
- large-muscle groups
- inner-ear mechanism for balance
- differentiation/integration
- knowing when to inhibit non-useful skills
what is “catching up”
in preterm infants, a period of growth after birth in which they put on weight rapidly
differentiation
mastery of component skills
integration
combining component skills in proper sequence into a coherent, working whole.
when does thumb use typically start?
7-8 months
when can babies coordinate the motion of their hands?
5-6 months
how does handedness develop
9 mo: no preference
13 mo: preference for one over the other
K: handedness established
auditory threshold
the quietest sound a person can hear
- for babies it’s higher
- hear best in the range of human voice
auditory (sound) localization
ability to detect where a sound is coming from
- newborns have this
when is full auditory capacity reached?
about 30 months
visual acuity
the smallest pattern that can be dependably distinguished
how is visual acuity measured
grey square and striped square, make stripes smaller and see when baby stares equally at both.
- by 1, baby VA same as adult
describe newborn colour perception
do perceive colour, but respond to higher saturation - less mature and efficient optical systems for colour detection
- by 3-4 months, cones and neural circuits have developed to be the same as adults
size constancy
the knowledge that an object’s actual size remains the same, despite changes in the size of its retinal image
- by 4-5 months
response to the visual cliff depth perception experiment
surface under glass plate drops off
1.5 mo. think it’s interesting (heart rate slows)
7 mo. scared (heart rate increases)
retinal disparity
differences in position on the right and left retinas for objects perceived to be nearby
- in use by 4-6 months
texture gradient
cues for depth perception arising from closer objects having finer details, farther ones coarser
interposition
near objects partially obscure far objects
edges
lines that mark the boundaries of objects
- 3-mo. infants use edges to identify objects
two visual systems
- perception of objects
- moving objects
infants and adults both have these
why do babies like to look at faces
- stimuli that move (eyes, mouth)
- dark/light contrast (eyes, lips, teeth)
by 2-3 months, can recognize familiar faces - basis for social relationships
how many neurons in neonate brain
100-200 billion
3 points about infant/toddler brain dev’t
- overall number of neurons decreases
- number of synaptic connections increases
- synaptic pruning begins around age 3
first tooth
5-9 mo
Benefits of breast feeding for the baby:
- disease protection
- cognitive development
- reduction in obesity
- better health in childhood and adulthood
Benefits of breast feeding for the mother:
- oxytocin reduces bleeding in uterus
- helps mother return to pre-baby weight
- strengthens bones
- reduces risk of ovarian and breast cancer
- suppresses ovulation
toilet training average at 18 mo
25%
toilet training average at 36 mo
60%
sleeping: By 3-4 months of age, infants
- can sleep 6-7 hours in a row
* spend 40% of sleep in REM stage
Risk factors for SIDS:
- sleeping on the stomach (back sleeping is safer)
- low birth weight or APGAR scores
- mother smokes during pregnancy or infancy
- soft bedding
- sleeping in a room that is too hot
- two or more layers of clothing while sleeping
Erikson’s first two stages
- Infancy: trust/mistrust - attachment
2. Toddlerhood: autonomy/shame-doubt - sense of self
Emotion
- a subjective thought or experience
- an accompanying pattern of neural activity and
physiological arousal - an observable behavioural expression
4 Characteristics of basic emotions:
- fast and automatic
- develop early in life
- universal among humans
- shared with other mammals
3-4 distinct kinds of crying:
basic cry - starts softly and gradually becomes more intense; usually occurs when a baby is hungry or tired
mad cry - a more intense version of the basic cry (cry expels large volume of air)
pain cry - begins with a sudden, long burst followed by a long pause and gasping
fussing - soft volume, unsteady whimper, when mildly
distressed
Shaken Baby Syndrome
brain injury that occurs when a baby is shaken (by arms, legs, chest or shoulder) or when the baby is slammed or thrown against an object
PURPLE crying (what do the letters stand for?)
Peak of crying (2 mo) Unexpected Resists Soothing Pain-like face Long-lasting Evening
display rules
unwritten expectations (norms) we have about when it is appropriate to show certain emotions
emotion regulation
strategies people use to influence their own emotional expressiveness. in infancy: - look away from the stimulus - move closer to a caregiver - mainly rely on others
Emotion Regulation - Toddlerhood
- development of behavioural strategies
- development of complex emotions
- external requirements
- use of language
emotional contagion
in infants, crying in response to hearing another infant cry, evident beginning at about 2 months
Still face paradigm
- infants expect others to show emotion and become distressed when they do not
- shows that even young infants experience emotions through interactions with others
social referencing
infants in an unfamiliar or ambiguous environment look at their caregivers, as if searching for cues to help them interpret the situation
Temperament - Rothbart (2007) (3 elements)
surgency/extroversion
negative affect
effortful control
surgency/extroversion
the extent to which a child is generally happy, active, vocal, and seeks interesting stimulation
negative affect -
the extent to which a child is angry, fearful, frustrated, shy, and not easily soothed
effortful control -
the extent to which a child can focus attention, is not readily distracted, and can inhibit responses
self-awareness
the ability to recognize one’s individuality
- toddlers start to use personal pronouns to describe themselves
- refer to things that belong to them
