Chapter 2: From Conception to Birth Flashcards
Definition of Human Development
how and why people - all kinds of people, everywhere, of every age - change
Chromosomes
Molecules of DNA. DNA consists of 46 chromosomes arranged in 23 pairs.
males have XY and females have XX
Chromosome Abnormalities
about once in every 200 births, an infant is born with 45, 47, 48, or even 49 chromosomes which produces syndrome.
most common condition is Down syndrome (trisomy-21).
about 1 in every 500 infants is born with only one sex chromosome (no Y) or with three or more
Dominant Genes
more influential than recessive gene (non-additive), can completely control the phenotype with no noticeable effect of recessive gene.
genes for blood type B and Rh-positive blood are dominant
Recessive Genes
less influential than dominant genes and are usually not expressed, sometimes they can be noticed, such as a dominant brown eye and recessive blue eye gene can result in hazel eyes
Heretibility
Statistical term that indicates what portion of the variation in a particular
trait within a particular
population is inherited.
environment can affect the expression of inherited genes
Genotype
An organism’s genetic inheritance, or genetic potential. Unique for each organism
Phenotype
The observable characteristics of an organism, including appearance, personality, intelligence, and all other traits
Zygote
Two gametes (sperm and ovum) combine and produce a new individual with 23 chromosomes from each parent
Embryo
3rd through 8th week after conception.
Primitive streak appears down middle of cell mass.
Head takes shape, eyes, ears, nose, mouth, form.
heart starts pulsating
webbed fingers and toes separate.
Fetus
week 9 after conception to birth.
genitals form end of 3rd month and sex hormones cause the difference of fetal brain organization.
weighs 3 ounces at 3 months.
Heartbeat detectable through stethoscope.
period of greatest brain growth at 4th, 5th, and 6th months.
prefrontal loves bot fully mature.
brain is far bigger than any other body part at birth
Monozygotic (Identical) Twins
originate from one zygote that splits apart early in development.
an incomplete split results in conjoined twins.
same genotype but slight variations in phenotype are possible due to environmental influences
Dizygotic (Fraternal) Twins
result from two separate ova by two separate sperm.
dizygotic twins have half of their genes in common and occur twice as often as monozygotic twins.
incidence is genetic and varies by ethnicity and age
Apgar Score
A quick assessment of babies heart rate, breathing, muscle tone, color, and reflexes.
completed twice (1 to 5 minutes after birth.
score of 0, 1 or 2 in each category.
desired score is 7 or above
Age of Viability
Age at which a preterm newborn may survive outside the mothers uterus if medical care is available.
about 22 weeks after conception.
Normal Birth
fetal brain signals the release of hormones to trigger the females uterine muscles, labor begins, the average duration for first born babies being 12 hours, quicker for later born babies
Medical Interventions
cesarean section (c-section), a surgical birth, fetus can be removed quickly, and usually safe for mother and baby, having lives when the fetal head is too large for the pelvis
Traditional and modern birthing practices
home births, hospital births, and a doula
Doula
a woman who helps with labor, delivery, breast feeding, and newborn care.
may also be related to lower rate of c-sections
Postpartum Depression
sadness and inadequacy felt by 8-15% of new mothers in the days and weeks after giving birth.
symptoms range from baby blues to postpartum psychosis.
depressed mothers find baby care burdensome and may think about mistreating the infant,
prenatal involvement can have beneficial effects.
some fathers are depressed themselves.
causes for postpartum depression vary
Teratogens
any agent condition, including viruses and drugs, resulting in birth defects or complications
Behavioral Teratogens
agents and conditions that can harm, the prenatal brain, impairing the future child’s intellectual and emotional functioning
Birth Defects
these occur from exposure to mass amounts of teratogens causing several defects to the fetus, one of them being fetal alcohol syndrome (FAS), which causes abnormal facial characteristics, slow physical growth, and retarded mental development
Germinal Period
the first two weeks of conception.
consists of rapid cell division and beginning of cell differentiation.
duplication and division within hour of conception.
development of placenta, as organ that surrounds developing embryo is attached to the wall of the uterus, and sustains life via the umbilical cord (nourishes and carries waste)
Embryonic Period
the 3rd through the 8th week.
basic forms of all body structures develop.
begins when primitive streak appears down the middle of the cell mass.
primitive streak becomes the neural tube and later forms the brain and spine. head takes shape, eyes, nose, and mouth form, heart begins to pulsate, and extremities develop and webbed fingers and toes separate
Fetal Period
the 9th week until birth. fetus grows in size and matures in functioning. genitals form at end of third month and sex hormones cause differences in fetal brain organization.
weighs about 3 ounces at s months.
heartbeat detectable through stethoscope.
All body parts and systems complete rental development.
Experience the period of greatest brain growth during the 4th, 5th, and 6th months.
Cortex not fully mature at birth.
Brain at birth is far bigger than any other part of the body.
Fertilization
One sperm penetrates the ovum. Nuclei (genetic material) of the male and female cells combine
Trimesters
germinal period, embryonic period, and fetal period
Kangaroo Care
Child-care technique in which the mother of a low birthweight infant holds the baby between her breasts.
Allows baby to hear mothers heartbeat and feel her body heat
Schema
cognitive framework or concept that helps organize and develop and interpret information
