ASU 3

• Germinal period

  • Takes place in the first two weeks after conception
  • Includes: creation of the zygote, continued cell division, attachment of the zygote to the uterine wall

  
• Blastocyst


  Inner layer of cells that develops into the embryo
• Trophoblast


  Outer layer of cells that provides nutrition and support for the embryo
• Germinal period


  • Significant developments
• Embryonic period


  • Occurs two to eight weeks after conception
  • Rate of cell differentiation intensifies and mass of cells is now called embryo
  • Support systems for the cells form and organs appear

  
• Three layers of cells


  • Endoderm
  • Mesoderm
  • Ectoderm
• Amnion


  Contains a clear fluid in which the developing embryo floats
• Umbilical cord


  Contains two arteries and one vein, and connects the baby to the placenta
• Placenta


  Disk-shaped group of tissues in which small blood vessels from the mother and the offspring intertwine but do not join
• Organogenesis


  Organ formation that takes place during the first two months of prenatal development
• Fetal period


  Period between two months after conception and birth
• Brain


  • Neurons: nerve cells which handle information processing at the cellular level
  • Important phases of development: neural tube, neurogenesis, neuronal migration, neural connectivity
• Teratogen


  Agent that causes a birth defect
• Teratology


  Field of study that investigates the causes of birth defects
• Teratogen influence


  • Dose
  • Genetic susceptibility
  • Time of exposure
• Prescription drugs that can function as teratogens


  • Antibiotics: streptomycin and tetracycline
  • Antidepressants
  • Hormones: progestin and synthetic estrogen
  • Accutane: acne medication
• Nonprescription drugs that can be harmful


  • Diet pills and high dosages of aspirin
• Psychoactive drugs


  Act on the nervous system to alter states of consciousness, modify perceptions, and change moods
• Psychoactive drugs

  • Caffeine
  • Alcohol
• Fetal Alcohol Spectrum Disorders


  Appear in the offspring of mothers who drink alcohol heavily during pregnancy
• Incompatible blood types


  Incompatibility between the mother's and father's blood types poses risk to prenatal development
• Environmental hazards


  Radiation, toxic wastes, and other chemical pollutants
• Maternal diseases


  • Rubella and syphilis
  • Genital herpes and AIDS
• Other parental factors


  • Maternal diet and nutrition
  • Maternal age
  • Emotional states and stress
  • Paternal factors
• Prenatal care


  • Screening for manageable conditions and treatable diseases
  • Programs include educational, social, and nutritional services
• Exercise during pregnancy


  • Helps prevent constipation
  • Conditions the body
  • Reduces excessive weight gain
  • Is associated with a more positive mental state
• Centering Pregnancy


  Relationship-centered program which provides complete prenatal care in a group setting
• Nurse Family Partnership


  Home visits by trained nurses beginning in the second or third trimester of prenatal development
• Birth process


  Three stages of birth

  
• First stage of birth


  • Uterine contractions are 15 to 20 minutes apart and last up to 1 minute
  • Longest stage

  
• Second stage of birth


  • Begins when the baby's head starts to move through the cervix and birth canal
  • Ends when the baby completely emerges from the mother's body

  
• Third stage of birth


  • Afterbirth: When the placenta, umbilical cord, and other membranes are detached and expelled
• In the United States, 98.6 percent of births take place in hospitals
• Midwives


  Caregivers who provide continuous physical, emotional, and educational support for the mother before, during, and after childbirth
• Medication


  Analgesia, anesthesia, and oxytocin
• Natural childbirth


  Reduces the mother's pain by decreasing her fear through education about childbirth and relaxation techniques during delivery
• Prepared childbirth


  • Special breathing technique to control pushing in the final stages of labor
  • Provides detailed anatomy and physiology course
  • Called Lamaze method
• Cesarean delivery


  Surgical procedure in which the baby is removed from the mother's uterus through an incision made in her abdomen
• Breech position


  Baby's position in the uterus that causes the buttocks to be the first part to emerge from the vagina
• APGAR scale


  • Assessing the health of newborns at one and five minutes after birth
  • Evaluates: infant's heart rate, respiratory effort, muscle tone, body color, reflex irritability