L4 (prenatal) Flashcards

1
Q

Preformationism

A

ultimate nativist theory of development in which prenatal life starts with a fully-formed individual (either in the sperm or egg) that gets bigger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Canalization

A

developmental reduction in plasticity of cells (i.e. reduction in ability to change as we age)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Beginning of life according to Beng of West Africa

A

life begins when newborns choose not to return to afterlife (wrugbe) rather they are born as a reincarnation of an ancestor

you know they’ve chosen to stay when their umbilical stump drops off a couple weeks post-birth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Gametes

A

haploid sex cells (eggs and sperm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Haploid cells

A

contain only half the genetic material found in other diploid cells (23 chromosomes instead of 23 pairs of chromosomes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Eggs vs sperm

A
  • much bigger (the largest cell) and formed prenatally
  • smaller and formed throughout the lifespan
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How many sperm fertilize eggs?

A

millions of sperm are ejaculated but only ~200 reach the egg (survival of the fittest)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Zona reaction

A

chemical reaction that blocks other sperm from entering an egg

takes around 6 hours for sperm to penetrate by 6-7 inches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happens to sperm when it fertilizes an egg?

A

sperm tail falls off and the rest goes into the egg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Zygote

A

fertilized egg with 23 chromosomes from mom and 23 chromosomes from dad

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

3 principles of prenatal development

A
  • cephalocaudal (head first)
  • basic first then more specialized (e.g. arm bud, hand paddle, then fingers)
  • important first (e.g. brain, heart)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

4 processes that transform a zygote into an embryo then into a fetus

A
  1. cell division (mitosis) resulting in the proliferation of cells
  2. cell migration
  3. cell differentiation
  4. apoptosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Cell migration

A

movement of cells from their point of origin to somewhere else in the embryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Cell differentiation

A

embryo’s unspecialized stem cells are transformed into ~350 different types of cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Apoptosis

A

selective death of certain cells that enables prenatal development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

3 periods in prenatal development

A

germinal (conception to 2 weeks), embryonic (3rd to 8th week), fetal (9th week to birth)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Germinal period

A

lasts until the blastocyst is implanted in the uterine wall where rapid cell division takes place

after conception, zygote > blastomere > morula > blastocyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When are twins determined?

A

germinal period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Monozygotic twins

A

identical, share the same genetic material, and result from the division of inner cell mass (usually share the same placenta)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Dizygotic twins

A

fraternal, share 50% of genetic material, and result from two different eggs getting fertilized by two different sperms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What happens to MZ twins when inner cell mass split happens in the first 2 days of the germinal period?

A

they get their own amniotic sacs and sometimes even their own placentas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What happens to MZ twins when the inner cell mass split happens late?

A

they may share the same amniotic sac and risk having umbilical cord entanglement; become conjoined if very late

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Is twinning hereditary?

A

identical twinning is uncommon and random while fraternal twinning is hereditary (tendency for hyper-ovulation is passed down)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Embryonic period

A

following implantation, blastocyst becomes an embryo, placenta and amniotic sac form, and chemicals are released to preserve the pregnancy (e.g. progesterone)

25
Q

Why is the embryonic period the most sensitive period of development?

A
  • rapid cell division takes place and major organs begin to form
  • when most miscarriages occur
26
Q

Amniotic sac

A
  • filled with amniotic fluid
  • protects the baby and lets it move unhampered by gravity
27
Q

Placenta

A

a semipermeable network of blood vessels that allow for the exchange of fluids between the fetus and their mom and produces hormones (e.g. estrogen, progesterone)

connected to the embryo by the umbilical cord

28
Q

What happens in weeks 2-3 of prenatal development (from germinal to embryonic period)?

A

inner cell mass folds into 3 layers: top, middle, bottom

29
Q

What does the top layer of the inner cell mass transform into?

A

nervous system (neural tube then brain and spinal cord), nails, teeth, inner ear, lens of eyes, outer surface of skin

spina bifida results from errors in neural tube closure so should take folic acid

30
Q

What does the middle layer of the inner cell mass transform into?

A

muscles, bones, circulatory system, inner layers of skin, other intestinal organs

31
Q

What does the bottom layer of the inner cell mass transform into?

A

digestive system, lungs, urinary tract, glands

32
Q

When do most spontaneous abortions/miscarriages occur?

A

before 11 weeks of prenatal development (during embryonic period) wherein most embryos have severe defects like aneuploidy (having extra/missing chromosomes)

33
Q

Androgens (e.g. testosterone)

A

produced by all fetuses but especially by genetically male fetuses, causing their testes to develop, which eventually produces testosterone itself

34
Q

Outcome of testosterone in a genetic female

A

congenital adrenal hyperplasia (male anatomy and brain differentiation)

35
Q

Outcome of lack of sensitivity to testosterone in a genetic male

A

androgen insensitivity syndrome (no male organs and often raised as a female)

36
Q

At what age does gender identity emerge?

A

present from age 2 or 3 but both cisgender and transgender children reliably identify with their gender by age 5

37
Q

How are males affected by x-linked recessive traits and y-linked traits?

A
  • males (XY) are more susceptible x-linked recessive traits as they only need 1 gene (from their mother) to express the trait
  • only males are affected by y-linked traits (from their father)

Examples:
* X-linked: hemophilia and fragile-x syndrome
* Y-linked: webbed toes

38
Q

When does apoptosis begin on a large scale?

A

24 weeks

39
Q

When do fetuses’ hair and neural cells tune to different sounds?

A

25 weeks

40
Q

Fetal breathing

A

movement of the chest wall, pulling in and expelling small amounts of amniotic fluid help the respiratory system become functional

41
Q

What are some signs that fetuses are practicing for life outside the womb?

A
  • bringing their hand to their mouth
  • fetal breathing
  • swallowing of amniotic fluid
  • cells in visual pathway engage in spontaneous activity
42
Q

How does fetal swallowing aid in their development?

A

swallowing of amniotic fluid promotes the development of the palate and aids in the maturation of the digestive system

43
Q

What is the relationship between activity differences before and after birth?

A

individual differences in activity level continue after birth (more active fetuses = more active children)

44
Q

When does fetal movement begin?

A

5-6 weeks (jerky and uncontrolled movement) and at 7 weeks, fetuses hiccup!

all during embryonic period

45
Q

Which time of day are fetuses most active (in terms of movement)?

A

early morning and late evening

46
Q

How is fetal movement related to cortical inhibition?

A

in the second half of pregnancy, only 10-30% of movement is thought to be related to cortical inhibition

GABA selectively attenuates activity of other neurons in the cortex

47
Q

When do fetuses engage in rest during pregnancy?

A
  • rest/activity cycles every few minutes at 10 weeks
  • sleep around 75% of the time toward the end of pregnancy
48
Q

How do fetuses experience senses of touch, taste, smell, and hearing?

A
  • feel their own movements
  • taste and smell amniotic fluid
  • hear their mother’s voice and bodily sounds
  • seeing is minimal (although eye mainly develops prenatally)
49
Q

When do fetuses habituate to speech sounds and dishabituate to new sounds?

A

32 weeks

50
Q

What are the preferences of full-term new borns?

A
  • mother’s voice and smell
  • food, music, words, stories they’ve experienced prenatally
51
Q

Teratogens

A

any environmental agent that can potentially cause harm during prenatal development

52
Q

Factors that influence the effect of teratogens

A
  • timing
  • individual differences in the fetus
  • has a dose-response relation (cumulative impact)
53
Q

Thalidomide poisoning

A

a teratogen that turns offs genes that regulate proteins that develop limbs

only takes effect prior to limb development

54
Q

Examples of teratogens

A

excessive alcohol intake early on, smoking, mercury, marijuana, illegal drugs, maternal diseases (e.g. flu)

though sleeper effects may make them difficult to detect

55
Q

Facial features of people with fetal alcohol syndrome

A

elfin ears, eye folds, large flat upper dentate, thin lips, small and widely spaced eyes

56
Q

3 maternal factors in prenatal development

A
  1. age (young and old parents put baby at risk)
  2. nutrition (e.g. folic acid and sufficient calories is important)
  3. stress-level (high stress impacts hormone environment in womb)
57
Q

What are the negative effects of pre- and post-natal depression and anxiety (of mother) on child development?

A
  • deficits in attention and cognitive control
  • more impulsivity
  • reduction in fetal brain connectivity
58
Q

Potential risks of administering SSRIs to mothers during pregnancy

A

cardiac issues and withdrawal symptoms at birth, but NOT autism

confound in link between SSRIs and autism