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CYC 302 Lecture Notes - Myelin, Neonatal Intensive Care Unit, Neurogenesis

Child and Youth Care
Course Code
CYC 302
Lili Ma

of 9
Child Development
Chapter 3 - Notes
Birth Complications
Gestation age: calculated starting from two weeks before conception
Extremely preterm baby: > 28 weeks
Preterm baby: 28-33 weeks (chances of survival are much higher)
Late preterm baby: 34-36 weeks
Full term baby: 37-42 weeks
Post-term baby: > 42 weeks
Complications: Preterm
Chance of survival increases with age (from 24 weeks)
NICU (neonatal intensive care unit) - preterm babies are usually placed here for a few days, or
low light intensity
low noise
^ The condition of the unit mimicks what went on in the mother's womb
Complications: LBW Infants
LBW (low birth weight): Baby weighs less than 5.5 pounds (2,500 grams)
preterm, or small for gestation age (SGA)
More medical complications and developmental difficulties
But, the majority of LBW babies turn out quite well
Intervention: Extensive touch ("massage therapy") for infants in NICU
Extensive touch is effective in stimulating growth for LBW babies
Study supporting these findings:
Researchers looked at rats. Baby rats were divided into two groups. One group of baby rats were
kept with their mothers, and the other group was seperated. The group of rats that stayed with
their mothers had normal physical growth (mothers of baby rats like to lick, and touch their
babies), and the other group did not
Newborn Reflexes
Reflex: Involuntary, automatic response to a stimulus
Happens spontaneously, cannot control it
Some are clearly adaptive (e.g., survival reflexes: blinking, sucking)
Some may not appear adaptive (e.g., primitive reflexes: they disappear after a few months)
If the reflex is adaptive, it will stick with you for life
If the reflex is primitive, it will disappear after a few months
Primitive reflexes are a consequence of neural development
After preterm babies with extreme low birth weight are born, there are no primitive reflexes
present which indicates that there may be something wrong neurologically
Survival (Adaptive) Reflexes
Breathing reflex: repetitive inhalation and expiration
Rooting reflex: The baby will turn his or her head in the direction of a touch on the cheek
Swallowing reflex
Eye-blink reflex: closing or blinking the eyes
Pupillary reflex: Constirciton of pupils to bright light and dilation to dark or dim light
Primitive Reflexes
Babinkski reflex: Fanning and then curling the toes (8 months - 1 year)
Palmar grasping reflex: Curling the fingers around objects that touch the baby's palm (first 3-4
Moro reflex: Throw out arms and arch the back, and then bring the arms toward each other as if
to hold onto something (4-6 months)
Swimming reflex: Actively move the legs and arms and involuntarily hold breath when immersed
in water (4-6 months)
Stepping reflex: When being held upright on a flat surface,the baby will step as if to walk (8
Newborn States
Regular sleep
Irregular sleep
Alert Inactivity
Alert Activity (happy, curious)
Crying (intensive)
Newborns spend 70% of their time sleeping
Newborns sleep twice as much as young adults
REM (rapid eye movement) sleep:
At least 50% of newborn sleep is REM sleep
As they get older (5 months old), that number decreases to 25-30%
Newborns spend so much time in "REM sleep" because of autostimulation theory
Biology and Behavior
Model of Interaction
3 Key Elements
Genotype (genes): The genetic material an individual inherits
Phenotype: The observable expression of the genotype (e.g., body characteristics [tall, short, fat,
skinny], behavior)
Environment: Everything other than genes