9.3-9.4

• Prenatal development


  Development from conception to birth
• Stages of prenatal development

  1. Germinal stage (weeks 1-2)

  2. Embryonic stage (weeks 3-8)

  3. Fetal stage (weeks 9-40)
• Germinal stage


  • Zygote forms, cell division (mitosis) occurs
• Embryonic stage


  • Embryo implants in uterus, placenta forms, organs start developing
• Fetal stage


  • Fetus develops recognizable human form, organ systems mature, rapid growth
• Fewer than one-half of all zygotes survive beyond the first two weeks
• The placenta provides nourishment and oxygen to the developing fetus
• Teratogen


  Any environmental agent that causes damage to the developing embryo or fetus
• Alcohol is the leading preventable cause of intellectual disabilities in children in the United States
• Fetal alcohol spectrum disorders (FASD)


  Birth defects associated with heavy alcohol consumption during pregnancy
• Smoking while pregnant can result in premature birth, low-birth-weight infants, stillbirth, and sudden infant death syndrome (SIDS)
• Babies born with a heroin addiction need heroin and must be gradually weaned under medical supervision
• Hospice


  Helps provide a death with dignity and pain management in a humane and comfortable environment, usually outside of a hospital setting
• Critical/sensitive period


  Specific period in pregnancy when an organ develops and is most susceptible to teratogens
• Living will


  A written legal document that details specific interventions a person wants
• Health care proxy


  Appoints a specific person to make medical decisions for you if you are unable to speak for yourself
• The average newborn weighs approximately 7.5 pounds
• Newborns are not completely helpless because their reflexes and sensory capacities help them interact with the environment from the moment of birth
• Newborn reflexes


  • Rooting reflex
  • Sucking reflex
  • Grasping reflex
  • Moro reflex
• Rooting reflex


  The newborn's response to anything that touches their cheek: When you stroke a baby's cheek, the baby naturally turns the head in that direction and begins to suck
• Sucking reflex


  The automatic, unlearned, sucking motions that infants do with their mouths
• Grasping reflex


  If you put your finger into a newborn's hand, the baby automatically grasps anything that touches the palms
• Moro reflex


  The newborn's response to the sensation of falling: The baby spreads the arms, pulls them back in, and then (usually) cries
• On average, newborns weigh between 5 and 10 pounds, and a newborn's weight typically doubles in six months and triples in one year
• The average length of a newborn is 19.5 inches, increasing to 29.5 inches by 12 months and 34.4 inches by 2 years old
• Growth slows between 4 and 6 years old: During this time children gain 5–7 pounds and grow about 2–3 inches per year
• Once females reach 8–9 years old, their growth rate outpaces that of males due to a pubertal growth spurt
• By 10 years old, the average female weighs 88 pounds, and the average male weighs 85 pounds
• This period of rapid neural growth is called blooming
• The brain of a 2-year-old is 55% of its adult size, and by 6 years old the brain is about 90% of its adult size
• During early childhood (ages 3–6), the frontal lobes grow rapidly
• The frontal lobes are associated with planning, reasoning, memory, and impulse control
• Motor skills


  Our ability to move our bodies and manipulate objects
• Fine motor skills


  Focus on the muscles in our fingers, toes, and eyes, and enable coordination of small actions
• Gross motor skills


  Focus on large muscle groups that control our arms and legs and involve larger movements
• Babies on average are able to hold up their head at 6 weeks old, and 90% of babies achieve this between 3 weeks and 4 months old
• Infants shake their head "no" around 6–9 months, and they respond to verbal requests to do things like "wave bye-bye" or "blow a kiss" around 9–12 months
• Children grasp the concept of object permanence by around 8 months old
• Toddlers (12–24 months old) have mastered object permanence, and they enjoy games like hide and seek
• Preschool-age children (3–5 years old) can count, name colors, tell you their name and age, and make some decisions on their own