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Developmental Psych
Chapter 3 - Prenatal Development
Question | Answer |
---|---|
Reproductive Capacity | WOMEN: higher risk of chromosomal disorder, especially past 35 MEN: concentration of sperm gradually declines after 30 |
Ovum | Largest cell in human body. Survives for 1 day after being released into the fallopian tube. |
Corpus Luteum | Secretes hormones to prepare the lining o the uterus to receive a fertilized ovum |
Sperm | Live up to 6 days |
Stages of Prenatal Development | (1) Zygote or Germinal Stages (2) Embryonic Stages (3) Fetal Stage |
Zygote Stage | First 2 weeks, fertilization in fallopian tube, attachment to wall of uterus. At 4 days, zygote referred to as BLASTOCYST. 7-9 days IMPLANTANTION. End of week 2 CHORION form -> VILLI -> PLACENTA. 30% do not survive zygote stage |
Implantation | Blastocyst burrows deep into uterine wall on the 7-9th day of fertilization. Trophoblast forms amnion. YOLK SAC emerges (produces blood cells until liver, spleen & bone marrow |
Blastocyst | Zygote after 4 days of fertilization, 60-70 cells form hollow, fluid-filled ball. Cells inside called EMBRYONIC DISK (develop in to fetus), outer ring of cells called TROPHOBLAST (become proactive covering and provide nourishment) |
Trophoblast | Outer ring of cell of blastocyst that forms AMNION which encloses organism in AMNIOTIC FLUID (regulates temperature & cushions). Later forms CHORION (surrounds amnion) where VILLI (finger-like blood vessels) develop |
Chorion | Form from trophoblast and surrounds AMNION. VILLI (finger-like blood vessels) develop and starts development of placenta |
Placenta | permits food and oxygen to reach fetus and waste products to be carried away. Connected to fetus by UMBILICAL CORD |
Umbilical Cord | Connects placenta to fetus. Grows to 1-3 feet in length. Delivers blood and removes waste products |
Embryonic Stage | Begins at 2 weeks UNtill 2 months. EMBRYONIC DISK forms ECTODERM, MESODERM and ENDODERM. Neural tube, Arms, legs, face, organs, muscles develop. Heart beats; embryo can respond to touch and move. 2nd month liver & spleen take over for yolk sac |
Ectoderm | Becomes the nervous system. Skin, hair, development of neural tube (which develops later to spinal cord) |
Mesoderm | Develops into muscles, skeleton, circulatory system, and other organs |
Endoderm | Develops into the digestive system, lungs, urinary tract, and glands |
Fetal Period or Period of the Fetus | 9–pregnancy end. Longest prenatal period. 9-12 weeks, external genitals formed. Muscles, organs more organized. Lungs begin to contract to prepare for breathing |
Second Trimester | Mother can feel fetus’ movements. LANUGO (white, downy hair) helps VERNIX (white, cheese-like substance) stick to skin. Rapid increase of glial cells. Brain mostly in place but can't control breathing & body temperature |
Third Trimester | Age of Viability (22-26 weeks where baby can first survive). Requires O2 to breath if born between 7-8 months. cortex enlarges & groves. Fetus responds to sounds. Fat layer develops; repositions to upside-down. Blinks & hears. More time awake |
Fetal Activity | Higher fetal activity in last weeks of pregnancy predict more active infant in first month of life |
SIDS | Theory that brain not developed enough to restart breathing if they stop breathing. To prevent, lie baby on back and remove stuffed animals and bumper pads |
Teratogen | Environmental agents that can produce abnormalities in developing fetus. Depends on dose, genetics, multiple factors, time of exposure. Major structural abnormalities in EMBRYONIC PERIOD, little to none in ZYGOTE, physical, minor structural in FETAL. |
Thalidomide | Morning sickness pill in the 60’s. Children born with underdeveloped limbs, and possible damage to ears, heart, kidneys and genitals. Crosses placenta. Below average IQ. |
DES or Diethylstilbestrol | Prescribed to prevent miscarriages. Daughters showed unusually high rates of cancer of the vagina, malformations of uterus and infertility. Sons showed increased risk of genital abnormalities and testicular cancer. |
Common Tetratogens | ASPIRIN (low birth weight, infant death around birth, low IQ), HEAVY CAFFEINE (3+ cups, LBW, miscarriage, newborn withdrawal symptoms), ACCUTANE (50% affected children <85 IQ, ANTIDEPRESSANTS, NICOTINE (LBW, abnormal placenta) |
Illegal Tetratogens | Cocaine, heroin, methadone (babies usually born addicted, low birth weight, breathing difficulties, physical defects, death around time of birth), marijuana (smaller head size and brain, depression, sleep, attention & memory problems later in childhood) |
Fetal Alchohol Spectrum Disorder | 3 types: FETAL ALCHOHOL SYNDROME (FAS) – slow physical growth, face & head defects, problems with learning, memory, social; PARTIAL FAS – similar to FAS, less severe; ALCHOHOL-RELATED NEURODEVELOPMENTAL DISORDER – least severe possible face defects |
Effects of Alcohol on Fetus | Interferes with mitosis and migration in neural tube. Draws oxygen away from developing embryo because it requires large quantities of O2 to metabolize |
Environmental Tetratogens | MERCURY, LEAD, PCBs, RADIATION, HERBICIDES (LBW, physical deformaties, mental retardation, brain damage, lead -> smaller heads) |
Disease Tetratogens | AIDS (20-30% transmit to infant. Drug ZDV reduces prenatal transmission by 95%), HERPES (major defects, infant infected during pregnancy or at birth), TOXOPLASMOSIS (from cat feces or raw meat) |
Effects of Exercise | Moderate, regular exercise (walking, swimming, biking, aerobics) linked to increased birth weight. Less back pain & other discomforts. Vigorous, extended exercise – working up a sweat more than 30 mins 4+ days a week – related to low birth weight. |
Effects of Nutrition | Malnutrition -> miscarriage (1st trimester), low brain weight, distorted stricter of organs, lifelong health problems |
Effects of Stress | Higher risk of miscarriage, prematurity, LBW, infant respiratory illness Also related to physical defects. Reduces blood flow and nutrients to uterus. Reduces infants capacity to manage stress |
Blood Incompatibility | RH Blood Incompatibility is most common. Mother build antibodies to foreign Rh protein in fetus (from father) destroying red blood cells, reducing oO2 supply to organs & tissues |
Toxemia | Sharp increase in blood pressure that causes swelling of face, hands and feet in 2nd half of pregnancy. Can lead to convulsions in mother and fetal death if not treated. Hospitalization, bed rest & drugs can lower blood pressure |