Chapter 3 Flashcards
Conception
A human female releases one egg from her ovaries about every 28 days & males make approximately 300 million sperm a day
Fertilization of the egg usually occurs in the fallopian tube
At least 25% of egg-sperm meetings will create a zygote, but fail to implant and are naturally removed from the body.
Sperm can last 3-5 days inside the female body
Germinal Period
The Germinal Period is about 2 weeks – the zygote has rapid development while it travels to implant in the uterine wall
Implantation
Once implanted into the uterine lining, the amnion forms, then the chorion, then the placenta, then finally the fetus is connected via umbilical cord.
Amniotic Sac
Fluid (amnion) filled sac which protects embryo
Chorion
Protects amnion
Period of the Embryo
Implantation to 8 weeks
Wks 3-4: Neural tube develops. Heart, muscles, & digestive tract begin to develop
Wks 5-8: Brain begins to develop with sense of touch. Limbs, face, & internal organs begin to form. Embryo can move & is 1 inch long.
Period of the Fetus
Week 9 to Week 39/40
Third Month (Weeks 9-12)
Organs become more developed & the fetus has better control over the limbs
2nd Trimester (Weeks 13-24)
Vernix develops – white coating on the skin to protect from the amniotic fluid.
Lanugo develops – light coat of fur to help vernix adhere. Many organs are becoming developed, especially the brain
Fetus is sensitive to sound and light.
3rd Trimester (Weeks 25-38/40)
- Brain continues to develop
- Fetus is viable, it can live outside of the mother’s body with support at 22-26 weeks. The fetus begins to develop a routine of sleep and wakefulness at 30-34 weeks.
- Fetus loses the lanugo and develops a layer of fat. The mother also passes antibodies to the fetus.
- Fetus positions downwards in participation for the birth
Teratogens
Environmental agents that can cause damage during the prenatal period
- Organism is most sensitive during the embryonic period to teratogens
- Shows the bidirectional influence between the child and environment
Factors influencing damage of Teratogens
- Dose (higher doses over time cause more damage)
- Heredity (some individuals are genetically better/less able to withstand environmental problems)
- Other influences: multiple teratogens, poor nutrition, no medical care, etc.
Prenatal Thalidomide Exposure
Morning sickness drug that was taken weeks 4-6 and led to serious deformities in limbs in offspring and issues with intelligence
Prenatal Diethylstilbestrol (DES) Exposure
Anti-miscarriage drug that led to increased cancer of the vagina & uterus in adolescent female offspring. Male offspring had more testicular cancer
Prenatal Isotrentinoin Exposure
Skull, brain, eye, heart, & ear abnormalities
Prenatal Aspirin Exposure
Brain damage / motor control issues
Prenatal Caffeine Exposure
Low birth weight
Prenatal Antidepressant Exposure
Premature delivery, low birth weight, & delayed motor development
Prenatal Cocaine, heroin, & methadone exposure
Lead to premature birth, low birth weight, brain abnormalities, physical defects, and possibility of death
Prenatal Cocaine Exposure
Leads to brain hemorrhages, seizures, perceptual, motor, memory, & language problems that last
Prenatal Marijuana Exposure
Causes issues with memory, academic achievement delays, impulsivity, & aggression in children
Prenatal Tobacco Exposure
Leads to low birth weight, miscarriage, premature birth, cleft palate, asthma, and infant death
Direct dose response
Newborns less responsive to sounds & are more likely to be chronic criers
Nicotine constricts blood flow across the body and can lead to a smaller or abnormal placenta
Prenatal Alcohol Exposure
Range of physical, mental, & behavioral outcomes when there is prenatal exposure to alcohol
Prenatal Radiation Exposure
Increased rates of miscarriage, brain damage, physical deformity, & slow physical growth
Even small levels of radiation can harm the child & may show up later in life with lower intelligence and slower rates of language and increased emotional disorders
What percentage of mothers smoke during pregnancy?
11%
Fetal Alcohol Syndrome
Slow growth, facial abnormalities (short eyelids, thin upper lip, smooth or flattened philtrum), brain injury
Partial Fetal Alcohol Syndrome
2 of 3 facial abnormalities & brain injury
Alcohol-Related Neurodevelopmental Disorder
3 areas of mental functioning delays but no problems with physical growth
What percentage of pregnant women drink at some point during their pregnancy?
25%
Environmental Pollution
Babies are born now with up to 287 industrial contaminants
Air exposure to environmental toxins can also damage the child and lead to small head, low birth weight, & impaired lung and immune system
Prenatal Mercury Exposure
Mercury: especially dangerous chemical that causes widespread neural damage. Frequently exists in fish.
Prenatal Lead Exposure
Lead: metal found in old paint and buildings that can lead to low birth weight, poor motor development, & brain damage
Birth: Stage 1
Longest stage; labor is usually 12-14 hours or more
Contractions help the cervix to widen (From 0 to 10cm) & becomes effaced (thinned)
Birth: Stage 2
About 50 minutes long - mother pushes the child out
Birth: Stage 3
Placenta is delivered after the baby in about 5-10 minutes
The Newborn
Contractions help the baby to produce cortisol, which narrows the blood vessels
Baby’s head is big relative to the rest of the body
Apgar Scale
Measured 1 minute and 5 minutes after birth
A score of 7 or better indicates the baby is healthy, 4-6 the baby needs vital signs stabilized, & below 3 is serious danger
Categories of the Apgar Scale
Appearance, pulse, grimace, activity, respirations
Preterm Infants
Born more than 3 weeks early or less than 5.5 pounds
–Birth weight is biggest predictor of infant survival and healthy development
Small-for-date infants: are below their expected weight for the pregnancy
Care for Premature Babies
Baby is sleepy and unresponsive, parents may bond less because they hold the child less
Parents who are caring and responsive have healthy preterm babies
Symptoms of being preterm
Brain abnormalities, frequent illness, school learning disabilities, & emotional and behavioral problems
Smaller bodies, lower intelligence tests, & have poor achievement in school
Preterm babies are more likely to be…
…abused because they require more stimulation to get a response.
Isolated mothers in poverty with premature babies…
…have especially unfavorable child outcomes.
Babinski Reflex
Stimulation: Sole of foot stroked
Response: Fans out toes & twists foot in
Duration: Disappears at 9 months to 1 year
Blinking
Stimulation: Flash of light or puff of air
Response: Closes eyes
Duration: Permanent
Grasping
Stimulation: Palms touched
Response: Grasps tightly
Duration: Weakens at three months, disappears at a year
Moro Reflex
Stimulation: Sudden move, loud noise
Response: Startles; throws out arms & legs & then pulls them towards body
Duration: Disappears at 3 to 4 months
Rooting
Stimulation:Cheek stroked or side of mouth touched
Response: Turns towards source, opens mouth & sucks
Duration: Disappears at 3 to 4 months
Stepping
Stimulation: Infant help upright w/ feet touching ground
Response: Moves feet as if to walk
Duration: Disappears at 3 to 4 months
Sucking
Stimulation: Mouth touched by object
Response: Sucks on object
Duration: Disappears at 3 to 4 months
Swimming
Stimulation:Placed face down in water
Response: Makes coordinated swimming movements
Duration: Disappears at 6 to 7 months
Tonic Neck
Stimulation: Placed on back
Response: Makes fists and turns head to the right
Duration: Disappears at 2 months
Tonic Neck
Stimulation: Placed on back
Response: Makes fists and turns head to the right
Duration: Disappears at 2 months
Regular / NREM sleep
Infant is at full rest & shows little or no body activity; eyelids are closed, no eye movements occur, face is relaxed, breathing is slow & regular
Irregular / REM sleep
Gentle limb movements, occasional stirring, & facial grimacing occur. Although eyelids are closed, occasional rapid eye movements can be seen beneath them. Breathing is irregular
Drowsiness
Infant is either falling asleep or waking up. Body less active than in REM sleep but more active than NREM sleep. Eyes open & close; when open, they have a glazed lock. Breathing is even but somewhat faster than in regular sleep.
Quiet alertness
Infant’s body is relatively inactive, with eyes open & attentive. Breathing is even.
Waking activity & crying
Infant shows frequent bursts of uncoordinated body activity. Breathing is very irregular. Face may be relaxed or tense & wrinkled. Crying may occur.
