week 2 Flashcards
1
Q
epigenesis
A
- the emergence of new structures and functions in the course of development
- the study of heritable changes in gene expression caused by interactions in our environment
2
Q
reproduction
meiosis
A
- cell division, eggs and sperm receive only one member from each of the 23 chromosome pairs
- produces gametes
3
Q
gametes
A
- reproductive cells (egg and sperm) that contain only half the genetic material of all the cells in the body
4
Q
process of reproduction
A
- egg launches from one of the woman’s ovaries into the fallopian tube
- as the egg moves through the tube towards the uterus, it emits a chemical substance that attracts the sperm towards it
- if sexual intercourse happens near the time the egg is released conception is possible
5
Q
sperm
A
- 500 million released each ejaculation
- 23 chromosomes, tail to propel
6
Q
conception
A
- union of an egg and sperm
- sperm must travel for 6 hours through the uterus to the fallopian tube where the egg is
- as soon as one sperm’s head penetrates the outer membrane of the egg, a chemical reaction seals the membrane preventing other sperm from entering
- the tail falls off and the contents of the sperm get released into the egg
- the nuclei of the 2 cells merge within hours
- the fertilized egg (zygote) now has full genetic material 23 chromosomes from each sex cell
7
Q
embryo
A
- developing organism from week 3-8 of prenatal development
8
Q
fetus
A
- developing organism from the week 9- birth
9
Q
mitosis
A
- cell division that results in 2 identical cells
10
Q
embryonic stem cells
A
- cells which can develop into any type of body cell
11
Q
androgens
A
androgens ( hormones includes testosterone): male genetalia
no androgens: (female genetalia
12
Q
glucocorticoids
A
- limit fetal growth
- help fetal tissues mature
- towards the end of gestation, glucocorticoid production increases for key organ maturation
13
Q
identical twins (monozygotic)
A
- twins that result from a zygote splitting in half, resulting in each of the 2 zygotes having the exact same set of genes
14
Q
fraternal twins (dizygotic)
A
- twins that result from 2 eggs released into the fallopian tube at the same time and are fertilized by 2 different sperm
- only half their genes in common
15
Q
inner cell mass layers
top
A
- nervous system, nails, teeth, inner ear, eye lens, outer surface of skin, other internal organs
16
Q
inner cell mass layers
middle
A
- muscles, bones, circulatory system, inner layers of skin, other internal organs
17
Q
inner cell mass layers
bottom
A
- digestive system, lungs, urinary tract, glans
18
Q
neural tube
A
- groove formed in the top layer of differentiated cells in the embryo that eventually becomes the brain and spinal cord
18
Q
placenta
A
- develops along with the embryo
- network of blood vessels, extends into the tissues of the uterus
- 90% of the cells in the placenta come from the fetus itself
- support organ for the fetus
- semi permeable, exchanges some material from the mother and baby
18
Q
amniotic sac
A
- develops along with the embryo
- membrane filled with a clear watery fluid in which the fetus floats
- protective buffer for the developing fetus, temperature, cushion
- connected to the placenta via the umbilical cord
18
Q
umbilical cord
A
- tube of blood vessles connecting the fetus and the placenta
18
Q
trimester 1
week and milestone
1
A
- zygote travels from fallopian tube to womb and embeds in uterine lining
- cells arrange into a ball, begin to form embryo and support system
18
Q
cephalocaudal development
A
- areas nearer the head develop earlier than those farther away
18
Q
trimester 1
week and milestone
2-3
A
- embryo forms 3 layers, which will become the nervous, circulatory and digestive system
- neural tube also develops
18
Q
trimester 1
week and milestone
4
A
- neural tube continues to develop into the brain and spinal cord
- primitive heart, arm and leg buds are visible
19
Q
trimester 1
week and milestone
5- 9
A
- facial features differentiate, rapid brain growth occurs
- internal organs form
- fingers and toes emerge
- start of sexual differentiation
20
Q
trimester 1
week and milestone
10-12
A
- heart develops basic adult structures
- spine and ribs develop more fully
- brain forms major divisions
21
Q
trimester 2
week and milestone
13-24
A
- lower body growth accelerates
- fully developed external genitalia
- body develops hairy outer covering
- fetus can make basic facial expressions
- fetal movements felt by mother
22
Q
trimester 3
week and milestone
25 - 38
A
- fetus triples in size
- brain and lungs sufficiently developed at 28 weeks, survival outside of womb
- functional visual and auditory systems
- fetus capable of learning
23
Q
movement
A
- 5-6 weeks after conception fetus moves spontaneously
- hiccups, burping reflex prepare for nursing
- swallowing, amnionic sac fluid, develop palate and digestive system
- “fetal breathing” moving chest wall in and out
24
Q
phylogenetic continuity
A
- humans share many characteristics and developmental processes with non human animals due to our shared evolutionary history
25
Q
habituation
A
- a decrease in response to repeated or continued stimulation
- only able to become boring if it was remembered
26
Q
dishabitation
A
- perceptible change in stimulus occurs making it become interesting again
27
Q
hazards to prenatal development
miscarriage
A
- most common
- 6 - 15% clinically recognized pregnancies
- 25 - 50% of women
28
Q
teratogens
A
- an external agent that can cause damage or death during prenatal development
- often occur in combination, poor nutrition, exposure to pollution, stress etc
29
Q
sensitive period
A
- period of time during which a developing organism is most sensitive to the effects of external factors
30
Q
thalidomide
A
- morning sickness drug
if taken when libs where growing between the 4th and 6th week after conception
31
Q
dose response relation
A
- the greater the fetus’s exposure to a potential teratogen, the more likely it is that the fetus will suffer damage and the more sever the damage is likely to be
- effect of exposure to an element increases with the extent of exposure
32
Q
Neonatal abstinence syndrome (NAS)
A
- fetus’s exposed to opioids in the womb are born
- low birth weight
- problems with breathing/feeding
- seizure
33
Q
teratogens
cigarettes
A
- mother and fetus get less oxygen
- slowed fetal growth
- low birth weight
- increased risk of sudden infant death syndrome (SIDS)
- lower IQ, hearing deficits, ADHD, cancer
- dose-response relationship
- greatest effects earlier in gestation
34
Q
teratogens
alcohol
A
- leading cause of fetal brain injury
- 1/10 use alcohol during pregnancy
- alcohol goes directly into the fetus’s bloodstream and amniotic fluid
- fetus has less ability to metabolize alcohol
- can result in fetal alcohol spectrum disorder (FASD) or fetal alcohol syndrome (FAS)
- intellectual disability, attention problems, hyperactivity
35
Q
teratogen
environmental pollutants
A
- disproportionately affects low income populations
- diets high in fish, lead,mercury, attention, cognition
- air pollution, low birth weight, neurotoxicity
36
Q
risks to developing fetus
age
A
- infants born to girls 15 or younger are 3-4x more likely yo die before their first birthfay than those born to mothers who are aged between 23 and 29
- dose response with increasing maternal age, autism
37
Q
risks to developing fetus
nutrition
A
- need to eat a balanced diet
- malnutrition can result in birth defects
38
Q
risks to developing fetus
disease
A
- contracting rubella early on, devastating developmental effects
- CMV, type of herpes, serious defects
- zika, microcephaly
39
Q
risks to developing fetus
maternal emotional state
A
- maternal prenatal depression, changes in brain structure in children aged 2-5, anxiety
- increased stress if lower socioeconomic group, developing country, food insecurity
40
Q
birth experience
A
- approx 38 weeks after conception
- fetus rotated to the head down position
- uterine contractions
- squeezing stimulates hormone production, amniotic fluid out of lungs
- survival and health of mother and baby, social integration of new person
41
Q
c sections
A
- 28% in canada
- assist infants and mothers facing birth complications
- scheduling conflicts
- maternal obesity
42
Q
state
A
- level of arousal and engagement in the environment
- ranging from deep sleep to intense activity
43
Q
sleep
A
- average newborn sleeps twice as much as young adults
- rapid eye movement sleep (REM) 50%, helps visual system
- learn during sleep, not disconnected from external stimulation
44
Q
crying
A
- crying because of: illness, hunger, pain, lack of control
45
Q
soothing
A
- swaddling, wrapping in a tight blanket restricting limb movement, tactile stimulation and warmth
46
Q
colic
A
- excessive, inconsolable crying for no apparent reason
- could include allergies, formula intolerance, immature gut development, excessive gassiness
- 18% of young infants
47
Q
apgar score
A
- method for evaluating the health of the newborn immediately following birth
- based on skin tone, pulse rate, facial response, arm and leg activity, breathing
48
Q
infant mortality
A
- death during the first year after birth
- rare
- different countries criteria for determining a live birth
49
Q
low birth weight (LBW)
A
- less than 2500g
- can be caused by teratogens
- higher incidence of developmental problems
- majority are in the normal range for their development
50
Q
premature
A
- any child born 37 weeks after conception or earlier
51
Q
small for gestational age
A
- babies who weigh substantially less than normal for their gestational age
52
Q
developmental resilience
A
- successful development in spite of multiple and seemingly overwhelming developmental hazards
