Prenatal Development Flashcards
1
Q
What happens during conception?
A
When 2 gametes are united/fused
2
Q
Define gametes
A
Sex cells/reproductive cells
Contains half the genetic information of a male/female
3
Q
What are the 2 types of gametes?
A
Sperm and egg
4
Q
How are gametes produced?
A
Cell division (meiosis)
Meiosis involves taking only half of the genetic material of all other normal cells in the body
5
Q
Where does fertilisation of the egg usually happen?
A
Fallopian tube
6
Q
List the 4 steps to conception
A
1) Egg launches from the ovaries to the fallopian tube
2) As egg moves toward the uterus, it emits a chemical substance to signal sperm to its direction
3) After intercourse, 500 million sperm is ejaculated into the vagina
4) Sperm unifies with egg
7
Q
What is the term used to describe a fertilised egg?
A
Zygote
8
Q
What are the 3 periods of prenatal development?
A
1) Germinal
2) Embryonic
3) Fetal
9
Q
When does the germinal period happen?
A
From conception - 2 weeks
10
Q
When does the embryonic period happen?
A
From week 3 to week 8
11
Q
When does the fetal period happen?
A
From week 9 to birth
12
Q
At what prenatal period does the zygote
becomes implanted in the uterine wall?
A
Germinal period
13
Q
At what prenatal period does rapid cell division take place?
A
Germinal period
14
Q
When does rapid cell division take place during the germinal period?
A
As early as 12 hours after fertilization
15
Q
Define mitosis
A
When the zygote doubles its number of cells roughly twice a day
16
Q
At what prenatal period does the zygote perform mitosis?
A
Germinal period
17
Q
What is the scientific term used to describe twins who are identical?
A
Mono-zygotic twins
18
Q
What is the scientific term used to describe twins who are fraternal?
A
Dizygotic twins
19
Q
How does the conception of monozygotic twins happen?
A
- When a single egg is fertilised by a single sperm but later on the zygote splits into 2
- Hence, the twins have the same genetic material as they came from the same cell
20
Q
How does the conception of dizygotic twins happen?
A
- When 2 separate eggs are released from the ovaries and are fertilised by 2 separate sperm cells
- Hence, the twins have different genetic material as they came from separate cells
21
Q
What is the term used to describe the results of the proliferation of cells?
Simply = When zygote keeps doubling (mitosis) until the zygote becomes a newborn with millions of cells
A
Cell division
22
Q
What is the term used to describe the movement of cells from point of origin to other locations in embryo?
A
Cell migration
23
Q
What is the term used to describe the transformation of stem cells into roughly 350 different types of specialized cell?
Simply = After continuous cell division, the cells start to specialise
A
Cell differentiation
24
Q
What term is used to describe the selective death of certain cells (apoptosis)?
A
Cell death
25
Define apoptosis
When cells are genetically programmed to die based on a specific timeline
26
At which prenatal period does major development occur in all the organs and systems of the body?
Embryonic period
27
At which prenatal period does development take place through the processes of...?
- cell division
- cell migration
- cell differentiation
- cell death
Embryonic period
28
At which prenatal stage does the zygote turn into an embryo after multiple weeks of mitosis?
Embryonic period
29
What happens to the inner cell mass and the rest of the cell after the zygote performs multiple weeks of mitosis?
Inner cell mass becomes the embryo
Other parts of the cell become the embryo's support system
30
What are the 2 types of support systems the embryo gets?
- Placenta
- Amniotic sac
31
What is the term used to describe a U-shaped groove formed from the top layer of differentiated cells in the embryo?
The neutral tube
32
What does the neutral tube eventually become?
It eventually develops into the brain and spinal cord
33
How does the neural tube become the brain and spinal cord?
One end of the tube will swell to become the brain and the rest of the tube becomes the spinal cord
34
When does the inner cell mass fold itself into 3 layers?
During the 2nd week
35
What are the 3 layers of the inner cell mass?
1) Top layer
- Nervous system
- Nails, teeth
- Inner ear
- Eye lens
- Outer skin
2) Middle layer
- Muscles
- Bones
- Circulatory system
- Inner skin
- Internal organs
3) Bottom layer
- Digestive system
- Lungs
- Urinary tract
- Glands
36
What term is used to describe a semi-permeable tube that allows the exchange
of materials between the bloodstream of the fetus and that of the mother?
Placenta
37
What is the purpose of the placenta?
It keeps the circulatory systems of the fetus and the mother separate but the semi-permeable membrane permits some material exchange (i.e. oxygen, waste, nutrients and CO2)
38
What term is used to describe the tube that contains the blood vessels that travel from the placenta to the developing organism and back again?
Simply = The tube that connects the fetus to the placenta
Umbilical cord
39
At which prenatal development period involves the continued development of physical structures and rapid growth of the body?
Fetal period
40
At which prenatal development period does the fetus receive antibodies from the mother in last month (particularly) of pregnancy?
Fetal period
41
At which prenatal development period does the fetus experience increasing levels of behaviour, sensory experience, and learning?
Fetal period
42
How long is the 1st trimester of pregnancy?
Week 1-Week 12
43
How long is the 2nd trimester of pregnancy?
Week 13-24
44
How long is the 3rd trimester of pregnancy?
Week 25-38
45
What term is used to describe the barrier that blocks against some, but not all toxins and infectious agents?
Placental membrane
46
What are the 2 components that protect the fetus?
1) Placental membrane
2) Amniotic sac
47
What term is used to describe a membrane filled with fluid in which the fetus floats, provides a protective buffer for the fetus and regulates temperature?
Amniotic sac
48
When does the fetus start spontaneously moving during prenatal development (at how many weeks)?
Around 5 weeks
49
When does the fetus start hiccupping during prenatal development (at how many weeks)?
At 7 weeks
50
Why does the fetus start hiccupping at 7 weeks?
- To practice a burping reflex (that they'll use after birth to get rid of excess air)
- Prepares fetus for eventual nursing by removing air from the stomach to make more room for milk
51
When does the fetus start hand-to-mouth movements during prenatal development (at how many weeks)?
After around 18-19 weeks
52
What does the hand-to-mouth movement tell us about the fetus' handedness?
If they often put their right hand in their mouth, they are most likely right handed
If they often put their left hand in their mouth, they are most likely left-handed
53
Explain what prenatal to postnatal continuity means
By 12 weeks after pregnancy, most of the
movements that have appeared during prenatal development will continue to be present at birth
54
Why does the fetus swallow amniotic fluid?
It promotes the normal development of the palate (tongue movement) and aids in the maturation of the digestive system
55
What does the movement of the chest wall and pulling in and expelling small amounts of amniotic fluid help the fetus with?
Helps the infants' respiratory system become functional
Breathing in amniotic fluid allows the fetus to practice breathing in oxygen after birth
56
When does fetal breathing (breathing in the amniotic fluid) become stable?
During the 2nd half of pregnancy
57
Define circadian rhythm
The natural cycle of physical, mental, and behavior changes that the body goes through in a 24-hour cycle
It is affected by light and darkness
58
When do the fetus’s sleep and wake states become similar to those of the newborn?
Near the end of pregnancy
59
What are the types of sensations the fetus experience whilst they're in the womb?
1) Tactile stimulation
2) Tastes and Smells of the amniotic fluid
60
How does the fetus experience tactile stimulation?
By grasping the placenta
61
How does the fetus develop taste and smell sensations?
By tasting and smelling the amniotic fluid
62
When does the fetus typically respond to sound?
From at least the 6th month of pregnancy
63
Who proposed that fetuses can actually see things whilst they're in the womb?
Reid et al.
64
What did Reid et al. discover about fetal visual abilities?
Fetus shows a preference for faces (Top-heavy shapes), suggesting postnatal exposure is not necessary
65
When do fetuses start showing signs of decreased responses to repeated or continued stimulation?
At 32 weeks of pregnancy
66
When do fetuses start showing signs of habituation and dishabituation?
In the 9th month of pregnancy (30-32 weeks)
67
What is the term used to describe the environmental agents that have the potential to cause harm during prenatal development?
Teratogens
68
When do teratogens cause damage in prenatal development?
Depends on the timing and type of teratogen
Many agents cause damage only if the exposure occurs during a sensitive period in the development
69
When is the most sensitive/critical period?
a. Germinal
b. Embryonic
c. Fetal
b. Embryonic
70
In the embryonic period, when is the development of the CNS most sensitive?
Around 3-5 weeks of pregnancy
71
In the embryonic period, when is the development of the heart most sensitive?
Around 3.5-6.5 weeks of pregnancy
72
In the embryonic period, when is the development of the arms most sensitive?
Around 4.5-8 weeks of pregnancy
73
In the embryonic period, when is the development of the eyes most sensitive?
Around 4.5-8.5 weeks of pregnancy
74
In the embryonic period, when is the development of the legs most sensitive?
Around 4.5-8 weeks of pregnancy
75
In the embryonic period, when is the development of teeth most sensitive?
Around 6.5-12 weeks of pregnancy
76
In the embryonic period, when is the development of the palate most sensitive?
Around 6.5-13 weeks of pregnancy
77
In the embryonic period, when is the development of the external genitalia most sensitive?
Around 7.5-15 weeks of pregnancy
78
In the embryonic period, when is the development of the ear most sensitive?
Around 4.5-14 weeks of pregnancy
79
What term is used to describe when increased exposure to potential teratogens are associated with greater probabilities of fetal defects and more severe problems?
Simply = The greater the fetus' exposure to a teratogen, the more likely it will suffer damage and the more severe the damage will be
Dose-response relation
80
What influences the effects of teratogens?
Individual differences
81
What makes it difficult to identify teratogens and their effects?
1) Their combination (difficult to pinpoint exactly what teratogens cause certain problems)
2) Sleeper effects (the problems derived from teratogens may be dormant until the child gets older)
82
What is the most human common teratogen?
Alcohol
83
What happens to the fetus when the mother consumes alcohol?
Fetal alcohol syndrome (brain injury)
84
How does alcohol get to the fetus during prenatal development?
Alcohol from the mother's blood is exchanged through the semi-permeable placenta and into the fetus' blood
85
What is the syndrome where maternal alcoholism causes delays in cognitive development, facial deformity, and other problems in children?
Fetal alcohol syndrome
86
What happens to the fetus when mothers smoke during pregnancy?
The fetus experiences reduced growth and low birth weight (reduced Oxygen)
87
Do e-cigarettes affect the fetus?
Yes.
The nicotine in the vape is a risk factor for fetal cardiac, respiratory, and nervous system development
88
What are the effects of smoking marijuana during pregnancy?
- Doubles risk of stillborn birth
- Memory, learning, attention, and impulsivity of the fetus is affected
89
What are the effects of doing cocaine during pregnancy?
- Fetal growth retardation, premature birth, attentional/arousal problems
- Withdrawal symptoms after birth
90
What are teratogens found in the environment?
- Pesticides
- Secondary smoker
- Pollution (air and noise)
- Herbicides
91
What happens to the fetus if they are met with environmental teratogens?
It affects their memory, learning, attention and impulsivity
92
What are occupational teratogens?
Teratogens that exist in the mother's occupation
e.g. farmer (pesticide exposure), factory worker (chemical exposure), chemist (chemical exposure), nurse (disease exposure)
93
What are the teratogens that are related to nutrition?
- Folic acid/vitamin B = can cause spina bifida (when the skin around the spinal cord is not close enough) in the fetus
- Inadequate nutrients = can cause fetus to be nutritionally deprived at birth
94
What are the teratogens that are related to diseases?
- Rubella, STIs
- Flu = mothers who had the flu during the 1st trimester increases the risk of their fetus developing schizophrenia
- Zika
- Age (older/younger women are at greater risk of negative outcomes)
95
What is the term used to describe the infant’s level of arousal and engagement in the environment?
State
96
What are the 6 states of arousal
1) Active sleep
2) Quiet sleep
3) Crying
4) Active awake
5) Alert awake
6) Drowsing
97
On average, how long does the crying state last for in newborns?
2 hours
98
On average, how long does the active awake state last for in newborns?
2.5 hours
99
On average, how long does the alert awake state last for in newborns?
2.5 hours
100
On average, how long does the drowsing state last for in newborns?
1 hours
101
On average, how long does the active sleep state last for in newborns?
8 hours
102
On average, how long does the quiet sleep state last for in newborns?
8 hours
103
What type of sleep is this? (REM or non-REM)
An active sleep state associated with dreaming in adults and is characterized by quick, jerky eye movements under closed lids
REM sleep
104
What type of sleep is this? (REM or non-REM)
A quiet or deep sleep state characterized by the absence of motor activity or eye movements and by regular, slow brain waves, breathing, and heart rate
Non-REM sleep
105
Why do infants spend 50% of their sleep time performing REM sleep?
1) REM helps with infants' visual system (due to high levels of internal brain activity that make up for infants' lack of visual stimulation)
2) Jerking during REM helps infants build sensorimotor maps
106
What does the auto-stimulation theory suggest about REM sleep?
Brain activity during REM sleep in fetuses and newborns makes up for the natural deprivation of external visual stimuli and facilitates the early development of the visual system
107
Does non-REM sleep increase or decrease with age?
Increase
108
Does REM sleep increase or decrease with age?
Decrease
109
In early infancy, why do infants cry?
Crying reflects discomfort or frustration
110
In later infancy, why do infants cry?
Crying gradually becomes more of a communicative act
With experience, parents become better at interpreting the characteristics of the cry itself
111
What does infant mortality mean?
Death during the first year after birth
112
What is the term used to describe death during the first year after birth?
Infant mortality
113
What affects the rate of infant mortality?
Poverty and lack of health insurance
114
What is the term used to describe infants weighing less than 5.5 pounds (2,500 grams)?
Low birth weight infants (LBW)
115
What is the difference between premature and low-birth-weight infants?
Premature = born before 37 weeks after conception
LBW = Weight under 5.5 pounds
116
What makes an infant premature?
If they were born before 37 weeks after conception
117
What is the term used to describe when an infant's birth weight is substantially less than normal for their gestational age?
Small for Gestation Age (SGA)
118
How can the negative effects of low-birth-weight infants be reduced?
Extensive parent contact and more touch for infants in neonatal intensive care
AKA "kangaroo care" to increase attachment
119
What are the complications that low-birth-weight infants face?
- Frequent illnesses
- Lower IQ score than expected for their age
- Lower educational achievement than expected for their age
120
What are the possible causes of low-birth-weight infants?
1) Teratogens (alcohol, smoking, drugs)
2) High rate of twin, triplet and multiple births as a result of increasingly successful treatments for infertility
121
What is this an example of?
Born in 1989 after just 27 weeks of gestation, Madeline weighed a mere 9.9 ounces
Low birth weight infant
122
What can help parents to take proper care of their low-birth-weight infant?
Educational programs designed to help parents with LBW babies learn about their revised developmental milestone timetable
Parents benefit from understanding that their LBW infants’ development will not follow the same timetable as that of a full-term infant
123
Gametes contain…
A. Twice the amount of genetic material of other cells in the human body.
B. Unique genetic information.
C. Half the amount of genetic information of other cells in the human body.
D. Teratogens which can damage embryonic development.
C. Half the amount of genetic information of other cells in the human body.
124
Which of the following is NOT a prenatal
developmental process?
A. Cell division
B. Cell migration
C. Cell differentiation
D. Cell accumulation
D. Cell accumulation
125
Which period of development takes place in the 3rd – 8th week of pregnancy?
A. Germinal phase
B. Zygotic phase
C. Embryonic phase
D. Fetal phase
C. Embryonic phase
126
Mary is 4 weeks pregnant and worried about the effects of teratogens on the development of her baby. The influence of teratogens is…
A. The same for all teratogens at every stage of development.
B. Subject to sensitive periods within pre-natal development.
C. The same for all fetuses.
D. Apparent from birth.
B. Subject to sensitive periods within pre-natal
development.
