T3 fetal and neonatal Flashcards
(100 cards)
1
Q
What is prenatal development?
A
growth of a fertilized egg between conception and birth
2
Q
What are the three stages of prenatal development?
A
germinal period, embryonic period, and fetal period
3
Q
How many days is full term gestation?
A
typically 266
4
Q
What is the neonatal period?
A
birth to 28 days
5
Q
What is fetal development?
A
time from 9th week of gestation to birth. birth ends the fetal period.
6
Q
What is the period prior to the fetal period?
A
embryonic period
7
Q
What are the main characteristics of the fetal period?
A
- 30 week period of development
- continual cell growth and differentiation
- fetus length will grow from 10cm to 53cm in 20 weeks
- weighs only 1 pound at 23 weeks gestation, but gains significant weight in the last 2 months
- organs developed by 4 months gestation, but cellular maturity (function) is not complete until after birth
8
Q
What system is integrated with the placenta through the umbilical cord?
A
circulatory system
9
Q
What does the fetus receive from the placenta?
A
oxygen and nutrients
10
Q
The heart begins as two parallel tubes. At what point do the tubes fold and form the heary, differentiating into 4 chambers?
A
at the point of fetus, 7-9 weeks
11
Q
Shunts in the fetus divert blood flow to bypass what organs until childbirth?
A
immature organs, like lungs and liver
12
Q
Where is the placental blood diverted first?
A
heart, upper torso, and brain
13
Q
Where is lower oxygenated blood shunted in the fetus?
A
lower body
14
Q
Fetal circulation runs in ___________; left ventricle provides 35% of CO and right ventricle 65%. the combination of the two is the total fetal cardiac output
A
parallel
15
Q
In the fetal heart, when do the myocytes start beating?
A
before fusion of the tubes.
16
Q
Where does the fetal heart beat begin?
A
in the final region oft he pacemaker
17
Q
What chamber of the heart in the fetus also acts as a pacemaker?
A
ventricles
18
Q
What is the rate of heart beat at 5 weeks gestation?
A
3.3 beats per day
19
Q
What is the rate of heart beat at 9 weeks gestation?
A
80-85 beats per minute
20
Q
The heart beat of the fetus continues to increase after 9 weeks, until reaching what rate
A
195 bmp
21
Q
In the fetal circulatory system, resistance in lungs is _______.
A
high
22
Q
Resistance in lungs is high in fetal circulation, because why?
A
lungs have limited metabolic needs because they are non-functioning.
23
Q
What is the blood flow of the lungs and liver in fetal circulation
A
blood just passes through
24
Q
What do umbilical arteries carry?
A
low oxygen blood and fecal waste
25
Where is iron concentrated for blood formation for the fetus?
mothers endometrium
26
What is the mechanism for early RBC formation?
iron is ingested into the embryo by trophoblastic cells and used to form early RBCs
27
At what week after fertilization is iron bound to Hb?
3rd
28
Where is iron stored in the fetus? what is its use?
liver; used after birth to make hb
29
Initially high resistance in pulmonary artery pressure drops with what?
an increase in systemic vascular resistance
30
When is surfactant produced?
last 3 months, but only enough produced for fetus to live until about 7th month gestation
31
What is surfactant?
lipoprotein complex with hydrophilic and hydrophobic regions that reduce surface tension.
32
What is the function of surfactant?
increases pulmonary compliance, preventing collapse of alveoli at end of expiration; prevents build up of fluid in alveoli
33
What type of cells produce surfactant?
type II alveolar cells
34
What fuel source is primarily used by the fetus?
glucose; fetus stores fat and protein
35
Vitamins are stored in the fetal liver. What are the main vitamins?
B12, folic acid C, D, E, and K
36
What is the function of Vit B12 and folic acid?
necessary for the formation of RBCs and nervous sytem
37
What is the function of Vit C?
necessary for bone matrix and connective tissue
38
What is the function of Vit D?
normal bone growth; mother needs adequate Vit D to absorb calcium from GI tract
39
What is the function of Vit E?
needed for early embryonic development
40
What is the function of Vit K?
used by fetal liver to create normal clotting factors
41
At what week is the brain present, but at the beginning of development?
week 10
42
What are activity-independent mechanisms?
genetically programmed to differentiate from stem cells, migrate, and create axons that reach the target
43
What are activity-dependent mechanisms?
after reaching target, synapse formation is dependent on activity, modifications of these synapses
44
Fetus moves but movements are jerky and not controlled. At what weeks are limb movements more powerful and felt by mother? movements are reflexive.
weeks 16 to 20
45
At what week is the fetus able to swallow several ounces of amniotic fluid/day?
week 16
46
At what week do nerves become covered with myelin (but not complete until 1 year)
week 18
47
At what week does the fetus start blinking?
week 24
48
At what week does the brain develop rapidly?
week 26
49
What are the function of the brain at week 26?
- nervous sys develops some control of organs
- cochlea developed
- brain forms smooth surface with grooves and indentations
- cerebellum developing very fast
50
At what week do the thalamic brain connections develop?
week 31
51
What occurs at 9-12 weeks?
- ossification of bone
- fingers and toes begin to develop
- eyelashes appear
- amniotic fluid is swallowed and urinated
- in males, testes descend
- intestines accumulate tarry, greenish black meconium (sterile)
52
What occurs at weeks 13-16?
- sensory organ development
- eyes move closer together
- mouth makes sucking motions
- ears move upwards
- scalp begins to grow hair
- kidneys are formed
53
What occurs at weeks 16-20?
- skin is coated with waxy protective substance, vernix caseosa
- silky hair covers all skin as lubricant
54
What occurs at weeks 21-31?
- eyelids are no longer fused
- bone marrow synthesizes erythrocytes
- eyelashes appear
- lungs produce surfactant (reduces tension in lungs)
- finger and toe nails begin to develop
55
What are prenatal screenings used for?
to detect genetic abnormalities/genetic assessment
56
When is an amniocentesis performed?
between 14 and 20 weeks gestation only.
57
When is Chorionic villus sampling/placenta sample taken?
9.5 to 12.5 weeks gestation
58
What sampling method is associated with a higher risk to the fetus?
chorionic villus sampling
59
What are the non-invasive prenatal screenings?
ultrasounds and blood tests
60
What are ultrasounds used for?
anatomy
61
What are blood tests used for?
Some trisomies can be picked up by detecting fetal DNA in maternal blood. If abnormalities are picked up, then invasive procedure used to confirm.
62
What are teratogens, give examples, and what are their results?
- compound that can permanently deform the function or structure of a developing embryo or fetus
- thalidomide, anti-nausea sedative
- severe limb defects in babies born in 1960s
63
What is the most common teratogen? What are its effects?
smoking; growth retardation, abruption of placenta
64
Fetal alcohol syndrome (FAS) effects what percentage of all births? what are its effects?
1%; flattened and thin upper lip, epicanthal folds, flattened nasal bridge, and short nose. Can have microcephaly, mental retardation and learning disabilities.
65
What are the effects of cocaine on the neonate?
produces growth restriction, preterm delivery, microcephaly, limb abnormalities, CNS abnormalities
66
What are the effects of ACE inhibitors on the neonate?
can cause fetal renal failure and pulmonary hypoplasia
67
How long is full gestation?
37-42 weeks
68
What is considered premature?
born before 37 weeks
69
What is a neonate?
first 28 days of life
70
What are the effects of low birth weight, less than 1000 grams at birth?
hypothermia, respiratory distress, hyperbilirubinemia, electrolyte imbalance, infections and feeding problems
71
What breath is the single most important breathe in the development of the respiratory system?
the first breath after birth.
72
What are the stimuli for the first breath after birth?
hypoxia, cold air. with delayed breath, the greater the hypoxia and hypercapnia.
73
In what position are the walls of the alveoli at birth?
collapsed
74
First breaths by neonate must be very strong to do what to alveoli?
open collapsed walls
75
At what week is surfactant made in the lungs?
24 weeks
76
Through what age does alveolar development continue?
through age 5
77
The first breath of the neonate requires excessive force to expel air. What does the next breath require?
much less force
78
neonates have periodic breathing pattern that can correlate to what?
changes in heart rate
79
What are the results of neonatal apnea?
excessive variation in blood gas concentration
80
Delayed or abnormal breathing can be caused by what two things?
general anesthesia to mother and/or head trauma during delivery
81
Prolonged hypoxia during delivery can severely depress respiratory center. what are some things that depress this respiratory center?
- compression of the umbilical cord
- premature separation of the placenta
- excessive contraction of the uterus
- anesthesia to the mother
82
What is "failure to breathe" and what are its results?
4 minutes or greater with no breathing. Causes death of the neonate. If the neonate survives, they will most likely have serious and permanent brain damage (cerebral palsy, effect on thalamus, loss of motor control).
83
What is respiratory distress?
failure to produce enough surfactant
84
When does respiratory distress present and what happens during it?
first hours to days after birth, alveoli fill with high protein fluid.
85
What population is at the highest risk for respiratory distress?
occurs mostly in premature neonates, and neonates whose mothers are diabetic.
86
Pulmonary vascular resistance decreases associated with what?
taking the first breath
87
Blood flow to the liver immediately _________ after birth because of the loss of placental blood flow.
increases
88
Changes in pressure between left and right atria causes blood to flow backward through __________ which will permanently close within months to years for 2/3 of people.
foramen ovale
89
Why is it typical that neonates have jaundice shortly after birth?
bilirubin formed by the fetus passes the placenta into the mother to be excreted through the mothers liver, but after birth, neonates liver must work.
90
Plasma bilirubin levels rise ____ times the first 3 days of life, and slowly return to normal as liver functions.
5
91
How is jaundice treated?
sunlight
92
What are intrinsic factors that cause hyperbilirubinemia?
enzyme conditions and sickle cell
93
What are extrinsic factors that cause hyperbilirubinemia?
sepsis and Rh incompatibility
94
What is severe hyperbilirubinemia called? What are its results?
Kernicterus; severe CNS injury
95
Neonate's stored glucose only lasts a few hours, it cannot do gluconeogenesis (liver not functional yet), and mother's milk is not fully developed. How does the neonate remedy this?
neonate begins to use stored protein and fat for the next few days
96
After birth, how much will the neonates weight drop?
20%
97
At what time intervals is the Apgar test given?
1 and 5 minutes
98
What does Apgar stand for?
```
Appearance
Pulse
Grimace
Activity
Respiratory
```
99
What Apgar score at 10 and 30 minutes is associated with long-term neurological damage?
below 3
100
Why is an Apgar score of 10 hardly seen?
normal early cyanosis
