Body, Brain and Health
Building blocks of growth and lifelong health
Celiac disease = inherited digestive problem in which gluten triggers an immune
response that leads to inflammation and damages the small intestine.
Catch-up growth = the body’s struggle to get back on the growth course it is genetically
programmed to follow.
a. The endocrine system
➔ the endocrine system consists of a group of endocrine glands that secrete hormones
➔ the most critical is the pituitary gland, which produces the growth hormone,
which then triggers testosterone and other male hormones (androgens)
➔ in girls, the ovaries produce larger quantities estrogen and progesterone
b. The brain and nervous system
➔ basic unit is the neuron
➔ the axon of one neuron makes a synapse with another neuron
➔ through myelination transmission is sped up
c. Principles of growth
● cephalocaudal principle (growth occurs in a head-to-tail direction)
● proximodistal principle (muscles grow from the center outward)
● orthogenetic principle (development starts globally and undifferentiated an
moves toward increasing differentiation and hierarchical integration)
The infant
➔ synaptogenesis = growth of synapses
➔ synaptic pruning = removal of unnecessary synapses
➔ the brain has great plasticity
➔ the critical period for brain development is during the late
prenatal period and early infancy, when it proceeds most rapidly
a. Rapid Growth
➔ infants grow rapidly (abrupt growth spurts)
➔ size during first months is related more to prenatal environment than genes
b. Newborn capabilities
Reflex = unlearned and involuntary response to a stimulus.
➔ survival reflexes have adaptive value (some permanent, some go after a few months)
, ➔ primitive reflexes are not clearly useful, but they are believed to be remnants of
evolutionary history that have outlived their purpose
● typically disappear during early months of infancy
● useful in diagnosing neurological problems in infants
SURVIVAL REFLEXES PRIMITIVE REFLEXES
Breathing reflex Babinski reflex (fanning then curling
toes when bottom of foot is touched)
Pupillary reflex and eye-blink Grasping reflex (curling fingers
around objects that touches baby hand)
Rooting reflex (turning a cheek Moro reflex (loud noises/sudden
toward a tactile stimulus) position change of baby’s head will
cause it to throw arms outward, arch
back then bring arms toward together)
Sucking reflex (sucking on objects Swimming reflex (active movements
placed into mouth) of limbs when immersed in water,
involuntarily holds breath)
Swallowing reflex Stepping reflex (infants held upright
will step as if to walk)
c. Behavioral states
➔ newborns spend half their sleeping hours in REM sleep
➔ by 3 months, most infants begin to establish a predictable sleep-wake cycle, which
becomes fairly stable by 6 months
d. Health and wellness
Congenital malformations = defects that are present at birth, either from genetic
factors or prenatal events.
➔ account for 1 out of 10 deaths during the first year
The child
a. Brain lateralization
Lateralization = specialization of functions of the two hemispheres of the cortex.
● left side: controls right side of the body, adept at the sequential processing needed
for analytic reasoning and language
