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Principles of Physical Development
• Cephalocaudal - development from head
down.
Structural Example
Cephalocaudal Development
Functional Example
Principles of Physical
Development
• Proximodistal: development from inside
out
• Mass-to-specific: gross motor skills (large
muscles) develops first followed by fine
motor (small muscles) skills
Growth
•
•
•
•
Newborn: 20 inches long; 7 1/2 pounds
1 inch per month
½ adult height by age 2
double weight by 4 months, triple by 12
months
• Head Circumference
• Fontanels
– Ossification
Growth
• Adolescence
– Puberty growth spurt - age 9 for girls, 11 for
boys
– Sexual maturation
Stages of Puberty
• Prepubescent Stage: no longer a child but not yet an
adolescent. Secondary sex characteristics begin to appear,
but the reproductive organs are not yet fully developed.
• Pubescent Stage : dividing line between childhood and
adolescence. Signs of sexual maturity appear - the
menstrual cycle in girls and the first nocturnal emissions in
boys. Secondary sex characteristics continue to develop.
Gametes are produced (not in the quantity/regularity of
Fully mature sex organs).
• Postpubescent Stage: Secondary sex characteristics
become well developed and sex organs begin to function in
a mature manner.
Brain Development
• Human brain – most functional and bestorganized 3 pounds of matter in universe.
• Part of Central Nervous System
• Controls voluntary and involuntary
activities
• 2 Hemispheres with 4 lobes
Development of Brain
Brain
Lobes
Occipital lobe – vision
Temporal lobe – speech/language and hearing
Parietal lobe – sensory motor processes
Frontal lobe – critical thinking
Nervous System Development
The Birth and Growth of Neurons
• Most neurons formed halfway through
gestation
• Virtually no synaptic connections
– it is experience and interaction with the
environment that forms the synaptic connections
• 83% of dendritic growth (connections between
synapses) occurs after birth
• Synaptogenesis
Childhood
• Myelination
• Lateralization
• Triples in weight by age 3
Use it or lose it – Natural
Selection of Brain Wiring
• Exposure to enriched environments with extra
sensory and social stimulation enhances the
connectivity of the synapses
• However, children and adolescents can lose
up to 20 million per day when not stimulated