ECED-1102

chromosomes

structures that store and transmit genetic info

dna

double stranded molecule of which chromosomes are made

gene

segment of dna along the length of a chromosome

genotype

an individual’s unique genetic info

phenotype

genetical features that are expressed, an individual’s observable features

in each cell, humans have…

23 pairs of chromosomes. 23rd pair = sex (males is xy, females is xx)

gametes

special sex cells, 23 chromosomes each

zygote

when gametes combine at conception, resulting in a 46 chromosome cell

fertilization

sperm and egg join —> new zygote with 46 chromosomes, 23 from each parent —> zygote is the very first cell of the baby

monozygotic twins

identical offspring that share nearly identical genetic makeup. occurs due to a separation of zygote into two or more clusters of cells.

dizygotic

fraternal twins that share about the same genetic makeup as any other sibling. occurs by the fertilization of two or more eggs.

ovulation pills

increase the release of eggs per cycle

iui - intrauterine insemination

assisted by a nurse or doctor. previously collected and tested sperm (from partner or donor) is injected into the vaginal canal, increasing the chances of a pregnancy.

ivf - in vitro fertilization

doctors retrieve a few eggs and, in a lab, fertilize with sperm. about a week after the egg is fertilized it becomes an embryo of ~100-150 cells, then implanted in the uterus.

mutations can happen by…

spontaneous (errors during dna duplications)

exposure to teratogens (chemicals, radiation, viruses)

heritability

i.e. down syndrome - 21st chromosome

passive correlation

child has no control over environment

i.e. athletic parents enroll their kids in sports and practice with them

evocative correlation

child’s genetic makeup/heredity influences the way their environment interacts with them

i.e. happy vs. sad, crying child

active correlation

individuals will engage in activities that support their genetic traits

niche-picking

i.e. tall kids play basketball

epigenetics

studies gene expression without changing the actual dna

environment can turn on/off genes through a process called methylation

germinal period

~14 days

conception to implantation of fertilized egg

gamete

period ends when blastocyst implants into uterine lining

embryonic period

3rd week

“embryo”

placenta forms

cephalocaudal (top-bottom) and proximodistal (in-out) development

developing embryo most vulnerable

fetal period

9th to 40th weeks

“fetus”

by 12 weeks, has all body parts

viable outside of uterus ~24 weeks

teratogens

“malformation”

environmental agents that can cause damage during the prenatal period and contribute to birth defects

effects of teratogens depends on dose and frequency, heredity, age and time of exposure, etc.

categories of teratogens

1. physical teratogens

2. metabolic conditions affecting pregnancy (e.g. obesity, diabetes, liver disease)

3. infections

4. drugs and chemicals

infectious diseases

virus (chicken pox, rubella, mumps, aids, herpes), bacteria (tuberculosis, syphilis), parasites (malaria, toxoplasmosis)

medication

any drug w/ molecules small enough to penetrate placenta, may end up in fetus’ bloodstream

importance of prenatal care and guidance, risk of self medicating when pregnant

sometimes benefit of medication may outweigh risks

the thalidomide tragedy

used in 1950s-60s to treat nausea during pregnancy

resulted in severe birth defects

“turning point in toxicity testing”

other drugs

opioids, cocaine, methamphetamine

fetus prematurity, low birth weight, brain abnormalities, physical impairments, death

infants exposed to opioids and other synthetic drugs are born addicted to them and have higher levels of cortisol in bloodstream

marijuana - increased risk of inattention, poor academic achievement, anger, aggression

tobacco

nicotine constricts blood vessels — less blood flow to the placenta

displacement of oxygen rich red blood cells that may damage cns, slowed fetus body growth

tobacco consumption associated with lower birth weight

secondhand smoking — respiratory illness, sids

alcohol

interferes with production and migration of neurons in the neural tube

body uses large quantity of oxygen to metabolize alcohol

epigenetics changes — physical and brain abnormalities

no quantity of alcohol is considered safe!

fetal alcohol spectrum disorder

frequent binge drinking — high risk of fasd

poor memory, lack of impulse control, attention span, motor coordination deficits, planning and reasoning

environmental pollution and radiation

some pollutants can severely damage prenatal dev

• mercury — physical deformities, abnormal speech, gross motor impairment

• lead — low birth weight, prematurity, brain damage, slower cognitive and motor development

• dioxins — thyroid abnormalities, later incidence of certain types of cancer

• plastic — toxic chemical

radiation can damage dna and may increase the risk of

• brain injury

• slow physical growth

• physical deformities

other maternal factors

exercise, nutrition, maternal age, stress, rh factor incompatibility

indigenous experiences

maternal health experiences may be impacted by

• colonization

• lack of culturally safe and inclusive practices

• limited healthcare options in remote communities

• socio-economic status or lifestyle

importance of culturally sensitive practices and consistent access to healthcare and education!!!