Principles of Physical Development

1
Principles of Physical Development

• Cephalocaudal - development from head down.
  
• Structural Example

2
Cephalocaudal DevelopmentFunctional Example
3
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

4
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

5
Growth

• Adolescence
• Puberty growth spurt - age 9 for girls, 11 for
  boys
• Sexual maturation

6
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.

7
Male Secondary Sex Characteristics

• Pubic hair appears about one year after the
  testes and the penis have started to increase in
  size
• Facial/body hair appear when the pubic hair has
  almost completed its growth.
• Muscles increase markedly in size and strength.
• Voice changes begin after some pubic hair has
  appeared. Voice breaks are common when maturing
  is rapid.
• Heightened Emotions Moodiness, sulkiness, temper
  outbursts, anxiety and irritability. Testosterone
  can also trigger a marked increase in aggressive
  behavior.

8
Developmental Order - Males
9
Female Secondary Sex Characteristics

• Hips become wider and rounder due to enlargement
  of the pelvic bone and development of
  subcutaneous fat.
• Breasts shortly after the hips start to
  enlarge, the breasts begin to develop.
• Hair pubic hair appears. Auxillary hair usually
  begins to appear after the first menstrual cycle.
• Voice becomes fuller and more melodious.
• Heightened Emotions Moodiness, sulkiness,
  temper outbursts and a tendency to cry at the
  slightest provocation These moods are especially
  common during the premenstrual and early
  menstrual periods.

10
Developmental Order - Females
11
Growth

• Early Adulthood
• height remains constant
• muscle tone/strength peaks in late teens/20s

12
Growth

• Middle Adulthood
• loss of fat and collagen in skin tissues
• aging spots
• thinner,graying hair
• lose 1/2 inch per decade in height, gain weight
• bone density begins decreasing

13
Menopause

• Peri-menopause transitional stage of two to ten
  years before complete cessation of the menstrual
  period (menopause). Age 35 to 50 years.
• decreasing levels of estrogen
• irregular menstrual periods
• Menopause when a woman has gone through 12
  months without menstruation (age 50)
• hot flashes, headaches, dizziness, heart
  palpitations, joint pain, osteoporosis

14
Growth

• Later Adulthood
• weight loss
• osteoporosis
• osteoarthritis

15
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

16
Development of Brain
17
Brain
18
Lobes

• Occipital lobe vision
• Temporal lobe speech/language and hearing
• Parietal lobe sensory motor processes
• Frontal lobe critical thinking

19
Nervous System Development
20
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

21
Photographs of Human Fetal Brain Development
Lateral view of the human brain shown at
one-third size at several stages of fetal
development. Note the gradual emergence of gyri
and sulci.
22
Childhood

• Synaptogenesis most occurs through 2nd year of
  life
• Myelination
• Lateralization
• Triples in weight by age 3

23
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

24
Adolescence

• Brain is full adult weight by age 16
• Continued myelination

25
Aging Brain

• Loss of neurons
• Diminished functioning in remaining neurons
• Changes in tissue surrounding neurons
• Declining levels of neurotransmitters
• Senile plaques

26
Brain Weight During Development and Aging
27
Chronic Brain Disorders

• Dementia general loss of intellectual abilities
• Alzheimer's brain atrophy neurofibrillary
  tangles

28
Themes of Development

• Continuity vs. Discontinuity
• Early vs. Later Experiences
• Nature vs. Nurture
• Critical Periods