Principles of Physical Development• Cephalocaudal - development from head

down.

Structural Example

Cephalocaudal DevelopmentFunctional 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 best-organized 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 – visionTemporal lobe – speech/language and hearingParietal lobe – sensory motor processesFrontal 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

Childhood• Synaptogenesis

• 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