develop u3 p1 Flashcards
(105 cards)
1
Q
What are the three main periods of prenatal development?
A
Germinal Period, Embryonic Period, Fetal Period
2
Q
What marks the start of the germinal period?
A
Fertilisation
3
Q
How long does the germinal period last?
A
First 2 weeks after conception
4
Q
What is a zygote?
A
The union of a sperm and egg cell
5
Q
What is the blastocyst?
A
A structure formed from the zygote after about 4-5 days post-fertilisation
6
Q
What are the two main components of the blastocyst?
A
- Trophoblast (shell) * Embryoblast (nucleus)
7
Q
What does the trophoblast become?
A
Structures responsible for nutrition and protection of the developing embryo
8
Q
What does the embryoblast develop into?
A
The embryo
9
Q
When does the germinal period end?
A
When the blastocyst is implanted in the wall of the uterus
10
Q
What begins after the germinal period?
A
The embryonic period
11
Q
How long does the embryonic period last?
A
From the 3rd through the 8th week after conception
12
Q
What are the support structures formed by the trophoblast?
A
- Amnion * Yolk sac * Allantois * Chorion
13
Q
What does the amnion become?
A
A fluid-filled sac surrounding the embryo
14
Q
What is the primary function of the placenta?
A
To facilitate metabolic transactions between mother and embryo
15
Q
What does the umbilical cord do?
A
Carries oxygen and nutrients to the embryo and removes carbon dioxide and metabolic waste
16
Q
What are the three layers of cells formed from the embryoblast?
A
- Ectoderm * Mesoderm * Endoderm
17
Q
What does the ectoderm develop into?
A
The nervous system, skin, and hair
18
Q
What develops from the mesoderm?
A
Muscles, bones, and the cardiovascular system
19
Q
What does the endoderm become?
A
The digestive system, lungs, urinary tract, and other internal organs
20
Q
When does the primitive streak form?
A
In the third week post-fertilisation
21
Q
What develops from the neural tube?
A
The central nervous system (brain and spinal cord)
22
Q
What is the average weight of the embryo by the end of the embryonic period?
A
~1 gram
23
Q
What characterizes the fetal period?
A
Development from the 9th week post-fertilisation until birth
24
Q
What happens to the indifferent gonad in the fetal period?
A
It differentiates into male or female sex organs
25
What is the role of the SRY gene?
Triggers the indifferent gonad to produce testes in male embryos
26
How much does the brain increase in size during 4 to 6 months?
6 times
27
What is the age of viability for a fetus?
Around the end of the 6th month (~22 to 24 weeks)
28
What happens to babies born before 27 weeks?
They need intensive care to survive
29
What does the fetus respond to in the last 3 months of pregnancy?
Noises, tastes of food, and behavioral patterns
30
What is the sleeper-effect principle?
Some teratogens cause effects that may not be apparent until later in life
31
What are teratogens?
Non-genetic agents that increase the risk of prenatal abnormalities and birth complications
32
What is the sensitive-period principle?
The effects of a teratogen are more severe when they occur during the rapid growth of a specific anatomy
33
What does the Individual Difference Principle state?
Not all embryos and fetuses are affected by a teratogen; susceptibility varies
34
What is the Dosage Principle?
The longer the exposure to or higher the dose of a teratogen, the more likely it will cause harm
35
What can result from a single teratogen?
A variety of defects
36
What are some examples of teratogens?
* Drugs (e.g., alcohol, cocaine) * Infections (e.g., AIDS, rubella) * Environmental hazards (e.g., lead, mercury)
37
What is a potential effect of thalidomide?
Birth defects in some mothers
38
What can contracting rubella during the first trimester lead to?
Severe birth defects such as blindness and cardiac abnormalities
39
What is the effect of syphilis during pregnancy?
Can cause miscarriage or severe damage to the child
40
True or False: Most pregnancies result in normal births.
True
41
What are spirochetes?
Micro-organisms that can cause disease and cannot cross the placental barrier until the 18th week of pregnancy.
42
What can spirochetes cause if transmitted after the 18th week of pregnancy?
Miscarriage or a child with eye, ear, bone, heart, and brain damage.
43
How does genital herpes affect newborns?
Results in mortality of 30% of infected newborns, and can cause blindness and mental retardation.
44
What is advised for pregnant women with active herpes?
To undergo cesarean delivery to avoid increasing the risk of infecting the baby.
45
What was the purpose of thalidomide in the 1960s?
To treat nausea and vomiting experienced in the first 3 months of pregnancy.
46
When was thalidomide found to cause severe birth defects?
When taken during the first 2 months of pregnancy.
47
What birth defect can occur if thalidomide is taken around the 21st day post-fertilization?
Child likely born without ears.
48
What birth defect can occur if thalidomide is taken around the 25-27th day post-fertilization?
Deformed arms or no arms.
49
What is the impact of alcohol consumption during pregnancy?
Disrupts the function of the placenta, affecting oxygen and nutrient supply.
50
What is Fetal Alcohol Syndrome (FAS)?
A condition affecting children of alcoholic mothers, characterized by microcephaly, deformed heart, and below average intelligence.
51
True or False: There is a well-defined sensitive period for the effects of alcohol on development.
False.
52
What substances pass from the mother to the embryo/fetus during cigarette smoking?
Nicotine and carbon monoxide.
53
What are some effects of cigarette smoking during pregnancy?
Cleft lip, abnormal lung function, increased risk of miscarriage, below average birth weight.
54
What is recommended for prenatal nutrition?
Healthy, high-protein, high-calory diet with specific weight gain recommendations.
55
What vitamins and minerals are important during prenatal development?
Magnesium, zinc, and folic acid.
56
What can folic acid prevent when taken during the first 8 weeks of pregnancy?
Down’s syndrome, spina bifida, and anencephaly.
57
What is the safest age range for pregnancy?
Between 16 and 35 years of age.
58
What are the risks associated with pregnancies in women older than 35?
Increased risk of miscarriage and chromosome abnormalities.
59
How does maternal stress affect fetal development?
Increased stress can influence fetal physiological state, potentially leading to developmental abnormalities.
60
What is amniocentesis?
A prenatal screening technique to detect chromosome abnormalities by sampling amniotic fluid.
61
What is chorionic villus sampling (CVS)?
A technique to extract fetal cells from the chorion for testing chromosome abnormalities.
62
What is the primary advantage of CVS over amniocentesis?
CVS can be performed earlier (8-9 weeks) and analyzed within 24 hours.
63
What is the main disadvantage of CVS compared to amniocentesis?
Higher risk of miscarriage (1/50 vs 1/150).
64
What is ultrasound imaging used for in prenatal diagnostics?
Detecting gross abnormalities, multiple pregnancies, and guiding other procedures.
65
What are the three periods of prenatal development?
Germinal period (zygote), embryonic period (embryo), fetal period (fetus).
66
What factors can increase the risk of abnormalities during prenatal development?
Teratogens, diet, stress, and timing of exposure.
67
True or False: Most pregnancies result in healthy babies.
True.
68
69
Birth (Stages 1, 2 and 3):
(what hormones are relased)
266 days post-fertilisation
Initiated by the release of:
corticotropin-releasing hormone from the placenta
oxytocin from the mother's pituitary gland
70
Perinatal environment:
The environment surrounding birth, Influenced by:
medications administered to the mother during delivery
delivery practices
immediate social environment after the baby is born.
Can impact the baby's well-being and future development.
71
Stage 1 of Birth:
Contractions that start occurring every 8-10 minutes and lasting about 30 seconds.
These contractions increase in frequency and duration, potentially reaching every 2 minutes and lasting for 2 minutes towards the end.
Contractions force the fetus's head against the cervix.
Ends when the cervix is fully dilated to approximately 10 cm, the diameter of the baby's head.
72
Stage 2 of Birth:
(when it starts, ends, and how long it lasts)
Commences when the baby's head emerges from the vaginal opening.
Can last between 30 to 90 minutes and sometimes involves an episiotomy to facilitate birth.
Concludes when the baby has completely exited the mother's body.
73
Stage 3 of Birth:
(what it is, how long it lasts, how long is active labor)
Expulsion of the umbilical cord (still connected to the baby) and the placenta from the mother.
This stage usually lasts only a few minutes.
The baby is born after an average of 12 hours of active labor for a first-born and 7 hours for a second-born.
74
Breech position:
baby is positioned feet-first or bottom-first.
Complications such as the umbilical cord becoming tangled and squeezed, potentially causing anoxia (oxygen deprivation) and brain damage.
75
Birth complications: Caesarean (C-) section:
(what it is + when its used)
Incision in the abdomen to deliver a baby.
May be used for fetuses in a breech position to prevent anoxia or in other cases of delivery complications.
76
Anoxia:
: A condition of oxygen deprivation, which if prolonged, can cause brain damage in a newborn, potentially occurring during a complicated delivery such as a breech presentation where the umbilical cord is compressed.
77
Birth complications: Intraamniotic infection
Infection and inflammation of tissues around the fetus
78
Birth complications: Shoulder dystocia
The fetus's shoulder lodges against the mothers pubic bone
79
Birth complications: Umbilical cord prolapse
The umbilical cord comes out before the baby
80
Birth complications: Uterine inversion
The uterus turns inside out
81
Apgar Scale:
| what it is, the 5 signs, when its taken, how its assessed & 5min score
Evaluate a newborn's physical condition shortly after birth.
It assesses five vital signs:
1. colour
2. heart rate
3. cry (reflex irritability)
4. muscle tone,
5. breathing (respiratory effort).
Each sign is scored 0, 1, or 2, and the evaluation is performed at one minute and five minutes after birth. A five-minute score of 7 or higher generally indicates the baby is okay, while a score below 7 (or any score of 0) suggests the need for emergency assistance. A perfect score of 10 is rarely attained.
82
Brazelton Neonatal Behavioural Assessment Scale (NBAS):
| when, what, how long it lasts, no. of reflexes/behaviour, categories, +
Administered during the first two days after birth - evaluates a newborn's neurological development and responsiveness to environmental stimuli.
It lasts approximately 30 minutes and measures 20 inborn reflexes and 26 behaviours categorized into:
1. interactions with others
2. motor behaviours
3. physiological control,
4. physiological responses to stress.
Parent participation in the NBAS can improve early parent-child connection and help parents understand their baby's abilities and preferences.
83
Prechtl’s Assessment of General Movements:
| what, how, when, normal vs abnormal patterns
Detects symptoms of cerebral palsy by evaluating the functionality of the nervous system through the observation of spontaneous movements
From early fetal life until around 6 months old.
These general movements are complex, frequent, and involve the whole body.
Abnormal patterns:
1. persistent "cramp-synchronised" movements (rigid and not smooth)
2. absence of "fidgety" movements (small, moderate speed, variable movements), can reliably predict cerebral palsy.
84
Inborn reflexes:
A series of involuntary, automatic responses to specific stimuli that are present from birth. These reflexes can be categorized as survival reflexes (having clear adaptive value, e.g., breathing, sucking, eyeblink) and primitive reflexes (considered remnants of evolutionary history with less obvious adaptive value, e.g., Babinski, Moro, stepping). The disappearance of certain primitive reflexes during the first few months of life is a sign of healthy nervous system development
85
Survival reflexes:
- breathing reflex (repetitive inhalation and exhalation)
- sucking reflex (sucking on objects in the mouth),
- rooting reflex (turning the head towards a touch on the cheek),
- eyeblink reflex (closing eyes to protect from bright lights).
86
Primitive reflexes:
Controlled by subcortical areas and disappears as the cerebral cortex matures
87
Babinski reflex
fanning of toes when the foot is stroked)
88
Moro reflex
extension of arms and arching of the back in response to a loud noise or sudden change in head position
89
Stepping reflex
stepping motions when held upright with feet touching a surface
90
Swimming reflex
stretching out arms and legs when held horizontally or placed in water
91
Palmer grasping reflex
curling fingers around objects touching the palm
92
Asymmetrical tonic neck reflex
fencing posture in response to head turning
93
Glabellar reflex
eyeblink response to tapping the forehead
94
Low birthweight:
A condition where a newborn weighs less than the average range (3.2-3.4 kg, with an optimal range of 3-5 kg).
95
Small-for-gestational-age (SGA):
A term used to describe babies who are born with a lower weight than expected for their gestational (developmental) age. SGA can be a cause of pre-term birth and is associated with a greater chance of developmental abnormalities compared to pre-term babies with expected weight for their gestational age.
96
Colostrum:
The thick, nutrient-rich fluid produced by the mother's breasts shortly after birth, before mature breast milk comes in. It is loaded with immune, growth, and repair factors and is provided during the first breastfeeding, often within the "golden hour".
97
Golden hour:
The first 60 minutes of a baby's life, considered a critical period for maximizing bonding between mother and child through skin-to-skin contact and breastfeeding.
98
Interoceptive orientation:
A state that predominates in newborns, characterized by an orientation towards their own bodily sensations and self-centred activity.
99
States of arousal
deep sleep, light sleep, drowsiness, alert inactivity, alert activity, and crying.
100
Basic emotions in newborns:
joy, sadness, anger, fear, surprise, disgust, dislike, and interest, and they serve protective functions.
101
Cyanosis:
A bluish discolouration of the skin, often seen in newborns, due to high levels of unoxygenated hemoglobin in the cardiovascular system. The skin typically turns pink as blood reoxygenates after the brief oxygen deprivation during the birth process.
102
Reflex irritability:
A component of the Apgar Scale, assessed by the baby's responses (cry) when secretions in the oropharynx and nasopharynx are suctioned. A strong cry is generally a positive sign.
103
Muscle tone
A component of the Apgar Scale that evaluates the degree to which the baby shows active motion of arms, legs, and body. Strong, active movement is scored positively.
104
Respiratory effort
A component of the Apgar Scale that assesses the baby's breathing and crying. A strong cry indicates a normal breathing rate, while a weak cry or slow, irregular breathing suggests a weak breathing rate.
105
Habituation (in the context of Glabellar Reflex)
Lack of habituation of glabellar reflex in adults can be a sign of neurological conditions like dementia and Parkinson's disease.
