WK1 Developmental Beginnings

• What are the two main parts of the PS218 Week 1 study material?

  Brains and bodies in development
• What are the key topics covered in Part 1 of the study material?

  • Prenatal development
  • Body development
  • Brain development
  • Risks to development
  • Postnatal development
• In which direction does prenatal body development proceed?

  Cephalocaudal direction
• What is the germinal stage of prenatal body development?

  0-2 weeks with rapid cell division
• What forms during the germinal stage?

  Embryonic disc
• What occurs during the embryonic stage of prenatal body development?

  Cell differentiation and structure formation
• What is the time frame for the fetal stage of prenatal body development?

  8-38 weeks

  
• What develops during the fetal stage?

  Organ systems develop and grow
• What basic structures are formed during the first 4 weeks of prenatal brain development?

  Embryonic disc and neural tube

  
• What are the three layers formed from the embryonic disc?

  Ectoderm, mesoderm, endoderm
• What does the hindbrain control?

  Basic biological/survival functions
• What is the role of the midbrain?

  Responses to sensory signals
• What develops in the forebrain?

  Cognitive functions
• What are the stages of cerebral cortex development after 10 weeks?

  1. Rapid neuron production (proliferation)
  2. Cell migration to final location
  3. Myelinisation (insulation of cells)
  4. Synaptogenesis (formation of synapses)
  5. Increased in-folding as brain mass grows
• What influences brain development?

  Genes and environment
• What is a risk to development related to genetics?

  Extra or missing genetic material
• What is Trisomy 21?

  Down's syndrome due to extra chromosome
• What are teratogens?

  Environmental agents causing abnormalities
• What is the significance of gestational age at birth?

  Indicates fetal development stage
• What can foetal anoxia lead to?

  Brain damage, e.g., cerebral palsy
• What are the key aspects of postnatal body development?

  • Relatively slow development
  • Takes ~25 years to reach full adult development
  • Most rapid in first two years
  • Double birth weight by 3 months
  • Triple birth weight by 12 months
  • Five times birth weight by 3 years
• What percentage of adult brain size is reached by age 3?

  ~80%
• What are the two processes of brain growth in early childhood?

  Synaptogenesis and myelinisation
• What happens to connections that are not activated in the brain?

  They die through pruning
• What are the implications of rapid brain development for cognitive and social development?

  • Impacts cognitive abilities
  • Influences social interactions
  • Supports psychological development
• What are the key points in the summary of body and brain development?

  • Brain development constrained by physical development
  • Infants are physically helpless
  • Rapid brain development impacts cognition and social skills
  • Prenatal risks affect future cognitive development
  • Long development period increases susceptibility to risks
• What occurs during the prenatal phase of development?

  • Germinal stage (0-2 weeks): embryonic disc forms
  • Embryonic stage (2-8 weeks): neural tube forms, structures develop
  • Fetal stage (9-38 weeks): cerebral cortex develops, organs operate

  
• What is the quote by Locke regarding the human mind at birth?

  The mind is a 'blank slate'
• What does James describe about the newborn's sensory experience?

  Feels it all as one great confusion
• What are the three reflexes infants are born with according to Piaget?

  Sucking, following with eyes, grasping
• What happens to most neonatal reflexes within the first year?

  They vanish due to cortical control
• What is the purpose of modern technology in studying prenatal development?

  Improves understanding of physical development
• What is the role of ultrasound in studying prenatal development?

  Creates pictures of structures and movement
• When does the fetus start responding to touch?

  From 8 weeks
• What happens when the amniotic fluid is sweetened?

  Swallowing increases in the fetus
• When does the fetus start responding to sounds?

  From 20-24 weeks
• What sounds permeate the fetal environment?

  Mother's heartbeat, voice, external sounds
• When does the fetus start reacting to light?

  From 26-27 weeks
• What is the significance of the reflexes for newborns?

  Important for survival and development

  
• How do neonatal reflexes reflect the functioning of the nervous system?

  They indicate normal functioning and control