Lecture 6 Flashcards
What is a passive gene-environment correlation?
When a child’s genes and their environment compliment each other
What is a reactive gene-environment correlation?
Environment doesn’t immediately match genetics, but you can get a reaction from your environment to match. Changing home environment
What is active gene-environment correlation?
The person seeks out their environment-child has to go a step further to find an environment that will match their genetics. Have to leave home environment to find matching environment
What else (other than genetics) can affect a child’s early traits and personality?
Prenatal experience.
How long is the cycle of menstration?
28 days
On what day is the egg released and how long does it live for?
Day 9-16, lives for 24-48 hours.
What is the percent chance that an egg and sperm will actually implant and lead to pregnancy?
25%
What happens with the other 75%?
Chemical pregnancy, spontaneous abortion, no conception
What percentage of pregnancies end in miscarriage and what can affect this percentage?
15%, age.
Where does conception take place?
The fallopian tube!
How many hours does it take for the chromosomes to combine into a zygote?
36 hours to divide into 2 cells, 48 to divide into 4.
How many specialized cells are there after 3 days of fertilization?
16-32.
How many days does it take for the zygote to enter the uterus and attach to the uterine wall?
Enters uterus: 5 days
Attachment: Day 6 or 7
How many days after fertilization can you detect pregnancy?
12-14 days
Why are you considered to be 4 weeks pregnant when really it’s only been 2 weeks?
Because we count pregnancy from the last day of your cycle.
What is implantation?
When the blastocyte connects with the moms blood vessels and signals are sent to the pituitary gland to start up pregnancy horomones.
What is the germ disc?
Centre of the blastocyst sphere-has potential to turn into a human while the rest of the blastocyte is nutrients for the germ disc.
When do the germ disc cells begin to specialize?
At 3-8 weeks
What is the ectoderm?
Outer layer- hair, skin, nervous system
What is the mesoderm?
Middle layer- muscle, bones, circulatory system, PNS
What is the endoderm?
Inner layer- digestive tract, lungs, CNS
When are we more likely to miscarry?
At 3-8 weeks when the germ disc becomes an embryo.
What is the placenta
Area that provides oxygen and food and takes away toxins. Also a filter to protect the embryo
What is the amniotic sac?
A bubble of water that cushions the embryo and gives it fluid movement. You can flavour the amniotic sac to bias the childs food preferences.
What is the umbilical cord?
Receives the nutrients and sends away waste.
What happens at week 3 of embryo development?
Vestigial structures, tails, gills.
What happens at week 4 of embryo development?
Organ and limb development, jaws, chin, cheek, ear canals, dots for eyes. Heart is the size of a poppyseed, neural tube development
What happens at week 5 of embryo development?
Mouth and tongue, paddle-like arm and leg buds, kidney formation
What happens at week 6 of embryo development?
Lips, nose, eyelids. Heart beats at 150 beats per minute. Spontaneous movements in limbs
What happens at week 7 of embryo development?
Brain and nervous system
What happens at week 8 of embryo development?
Bones and cartilage form, indentations turn to knees and ankles, arms of moving
What happens during weeks 9-38?
Rapid and most noticeable growth, most systems start to function, looks more like a baby
What happens during weeks 9-12? (period of fetus)
Fingernails and toenails develop, nasal passages and side ears, hands and feet, sexual development-release of testosterone, change ovaries to testes, vagina to penis
What happens during weeks 13-16?
Circulatory system working, mom starts to feel movement, strengthening of neck, hair growth, wiggle fingers and suck thumb, eyes work
What happens during week 17-20?
Eyebrows, eyelashes, scalp hair. Lanugo-hair all over body. Vernix-waxy, cheese-like coating. Yawning and hiccups. Sex determined by ultrasound
What happens during weeks 20-24?
Swallowing movements, taste preferences (including amniotic fluid), preferences for rhymes and voices, sensitive to light, rapid skin growth
What happens during weeks 25-28?
Age of viability (22 wks is earliest), advanced lung development, brain specialization, body temperature regulation
What happens during weeks 29-32?
Body fat development, insulation for temperature regulation, lunago sheds
What happens during weeks 33-38?
Rapid brain development, movement and positioning for birth, digestive system completion
How long is each period in pregnancy respectively (zygote, embryo, fetus)
Zygote: 2 Weeks
Embryo: 8 weeks
Fetus: 30 weeks
