Flashcards in COBINE FETAL PHYSIO Deck (100):
What is the weight change of the kid during the pregnancy?
first 3 months unnoticeable
last 2 months, 2 lbs gained per month!
What is the length change of the kid during the pregnancy?
the length increases steadily throughout the pregnancy
When does the heart start beating? What is its rate at this point?
@ 26 days
65 beats per minutes
The heart rate increases until it gets to _____ right before delivery.
140 beats per minute
Where are nucleated blood cells formed in the kid?
nucleated RBCs are only formed in the 3rd week from the yolk sac & mesothelial layer of the placenta
After the 3rd week...what happens to the kid's blood supply?
4-6 weeks: non-nucleated RBCs formed in the liver (then spleen)
In the 3rd or 4th month until birth there is another shift in RBC production. Where are they formed now?
bone marrow forms it in addition to the liver & spleen
After birth what are the sources of RBC production?
only the bone marrow after birth
What is the significance of the mnemonic Young Liver Synthesizes Blood?
Y: Yolk Sac
B: bone marrow
When do respiratory movements first begin in the kid?
during the 1st trimester
When do respiratory movements end in the kid? What is the purpose of halting this?
inhibited in the last trimester
**to prevent debris from meconium from entering the lungs
What do the baby lungs secrete to stay clean?
the alveolar epithelium secretes fluids to keep the airways clean...
When do skin reflexes begin in the fetus?
@ 3-4 months
T/F The development of the cerebral cortex is complete at birth.
False. the higher function of the cerebral cortex is still underdeveloped @ birth
When does the kid complete the myelinization of the tracts of his nervous system?
this takes 1 year to complete
What is the brain mass of the kid @ birth, 1 year, 2 years?
Birth: 26% of the adult brain
1 year: 55% of the adult brain
2 years: 80% of the adult brain
What is the substance that is excreted by the fetus?
Describe the GI development in utero.
@4.5 months: fetus ingests & absorbs large quantities of amniotic fluid
@6-7 months: GI fcn approximates that of a newborn
When do the fetal kidneys start developing?
@ the 5th week of gestation
When do the fetal kidneys begin excreting urine?
b/w 1st & 2nd trimesters: b/w 3-4 months gestation
The kidneys help with an electrolyte/fluid balance. When does this fcn begin with the fetal kidneys? When is this fcn fully developed?
after 4.5 months
takes months after birth to fully develop
What is the timeline for organ system development?
1st month: organ systems are all outlined, not fully developed
2nd & 3rd months: important times for development
4th month: organ systems very similar to a newborn-->still undergoes cellular development until birth
What are the systems that aren't fully developed @ birth?
When is the critical period? What is this all about?
**during this time organ systems are rapidly developing & highly susceptible to teratogens
**also women often don't know they are pregnant until a few months in...could have been drinking alcohol & causing damage.
Some important substances build up in the fetus during the gestational period. What are 3 important substances that build up? List them in order of most accumulated-->least accumulated.
When does most of this accumulate?
most of it accumulates in the last month of the gestational period.
Does the buildup of calcium in the fetus drain the mother or compromise her bone health?
Not really b/c only represents 1/50th of the mother's calcium content. But...during breastfeeding it often can.
Why does the fetus need so much iron accumulation?
b/c @ 3 weeks it starts making RBCs-->needs it for the hemoglobin.
Also, 1/3 of the accumulated iron is stored in the liver for future formation of hemoglobin.
What are the most important vitamins for the fetus?
Why is Vitamin B important for the fetus?
Vit B12 & folic acid vital b/c it helps w/ RBC production
Why is Vitamin C so important for the fetus?
helps w/ bone matrix & CT fiber formation
Why is Vitamin D so important for the fetus?
helps w/ calcium uptake--vital for bone growth
Why is Vitamin E so vital for the fetus?
maintains normal development in the early embryo
prevents spontaneous abortions
Why is Vitamin K so important for the fetus?
formation of blood coagulation factors in the liver: like factor VII & prothrombin
Where does the baby get its Vit K source from?
the mom b/c it comes from bacterial action in the colon
When does normal respiration start happening in a newborn? How long can a baby not breathe before brain damage starts occurring? How long can a baby not breathe before he dies?
usu within seconds
8-10 minutes w/o breathing: permanent brain damage
10-15 minutes w/o breathing: death (adults die in 4 min-->those little guys are resilient)!
What is it that prompts a normal respiratory rhythm in a newborn?
the low O2 from the birthing process & the cool temp on the skin of the new environment
**if don't breathe right-->prompted to do so by increasing CO2 & decreasing O2 in their bodies.
What does delayed & abnormal breathing lead to? What are some things that can cause this?
umbilical cord compression
premature placental separation
excessive contraction of the uterus
What are the specific dangers of hypoxia to the child?
depression of the respiratory center
lesions in the thalamus, inferior colliculi, parts of brainstem
**affects motor functions of the body
What is the fcn of the thalamus? Inferior colliculi?
Thalamus: regulates consciousness & sleep
Inferior Colliculi: auditory fcns
How much negative pressure is required to open the baby's lungs for the first time?
25 mmHg negative pressure
The first inspiration can create up to ____ mmHg of negative pressure in the intrapleural space. THis amount reduces in time, however, & the second breath is much easier. When does breathing become normal for the baby?
breathing becomes normal after about 40 minutes
Which is oxygen rich & which is oxygen poor? Umbilical arteries & umbilical veins.
Umbilical Arteries: oxygen poor
Umbilical veins: oxygen rich
Describe the circulation of the fetus in utero w/ a focus on liver, lungs & placenta.
Liver & lungs partially functional b/c placenta is doing all of the work, don't require as much blood so they are bypassed a lot.
Placenta needs a LOT of blood.
Describe the circulation of the fetus in utero w/ a focus on the umbilical vein's journey.
Umbilical vein has oxygen rich blood.
This bypasses the liver via the ductus venosus. This goes into the IVC & then the RA. It goes thru the foramen ovale into the LA. Then the LV & out thru the aorta to the vessels of the head & forelimbs.
Describe the circulation of the fetus in utero w/ a focus on the umbilical artery's journey.
SVC has oxygen poor blood. This empties into the RA-->RV. This goes into the pulmonary arteries. It goes thru the ductus arteriosus to get to the descending aorta. It splits into the umbilical arteries & goes back out to the placenta to get re-oxygenated.
In terms of pressures, what are some changes that happen after birth?
systemic vascular resistance increases w/ loss of the placenta
increased pressures in the aorta, LA & LV
pulmonary vascular resistance decreases-->lung expansion possible
RV & arterial pressure reduced
Describe the closure of the foramen ovale.
After birth, the pressure on the left side of the heart increases.
Low RA pressure & high LA pressure makes blood want to flow from L-->R thru the foramen ovale. There is a valve on the left side of the heart that creates a functional closure of the foramen ovale when this happens. After this, it is known as the fossa ovalis.
Describe the closure of the ductus arteriosus.
Normally, this would allow blood from the pulmonary artery to get into the aorta. With birth, you have decreased pressure in the pulmonary artery & increased pressure in the aorta. Then blood wants to flow from the aorta-->pulmonary artery. Within the first 1-8 days a functional closure begins. Then, within 1-4 months there is complete occlusion of the ductus arteriosus b/c of the deposition of fibrous tissue.
Describe the closure of the ductus venosus.
Normally, the umbilical vein bypasses the liver by putting blood thru the ductus venosus & then into the IVC. At birth, blood no longer flows thru the umbilical vein. At first, the portal vein still bypasses the liver by putting blood into the ductus venosus. But then, w/i 1-3 hours after birth-->it constricts. Blood starts going into the liver & the portal venous pressure raises from 0mmHg to 10mmHg
Compare a newborn's respiration with that of an adult.
total minute respiratory volume 2X that of an adult
FRC 1/2 of an adult
Compare a newborn's cardiac output with that of an adult.
CO is 2X that of an adult.
Compare a newborn's arterial pressure with that of an adult.
Starts off super low (70/50) & then increases in the next few months to 90/60
Eventually, increases to adolescent values of 115/70.
What is the rough RBC count of a newborn?
How does the RBC count change with umbilical cord stripping? What is this?
can rise from 3 X 106-3.75 X 106
**milking the umbilical cord blood back into the infant
Good: raises the hematocrit
Bad: some believe it could cause pulmonary edema
How does the WBC count of the infant compare to that of an adult?
5X that of an adult
How does the kid handle bilirubin from RBC breakdown in utero v. after birth?
in utero: excretes it thru the placenta
after birth: uses the liver (but at first the liver isn't fully functional)
B/c the liver isn't fully functional after birth, what happens to bilirubin levels in a newborn? What is this called?
they rise to about 5X what they were 3 days after life...
this is called physiological hyperbilirubinemia (mild jaundice)
What is erythroblastosis fetalis?
happens w/ a Rh incompatibility b/w the mother & fetus
maternal system creates antibodies against the RBCs of the infant
this causes large quantities of bilirubin to be released into the plasma.
Newborns are particularly susceptible to over hydration & under hydration. Explain why.
fluid intake & excretion is 7X that of an adult
kidney development isn't complete until 1 month after birth
infants can only conc'n urine 1.5X (as opposed to 3-4X)
Newborns are particularly susceptible to acidosis. Explain why.
their metabolism is 2X that of an adult
therefore, 2X the acid formation
naturally slightly acidotic
The liver is only marginally functional at birth. What are the implications of this in terms of bilirubin excretion & clotting?
Bilirubin excretion is poor at first in a newborn b/c difficult for the liver to conjugate the bilirubin with glucuronic acid
**poor formation of blood coagulation factors
Why might a newborn develop hypoglycemia?
one possible reason is that the liver isn't fully functional to perform gluconeogenesis.
Why might a newborn develop hypoproteinemic edema?
b/c of reduced plasma protein formation b/c the liver isn't yet fully functional
What is the first line of nutrition for a newborn? Hint: only lasts a few hours
glycogen stores in the newborn
T/F Blood glucose in an infant can easily fall to half of normal.
True. This is b/c the liver isn't fully functional to perform gluconeogenesis.
What is the second line of nutrition for a newborn? This lasts 2-3 days while the mother's milk is coming in.
utilization of stored fats & proteins
T/F Newborns have a steady increase in their weight from birth to adolescence.
False. there is often a 5-10% reduction in weight while the mother's milk supply is coming in.
Why don't you feed a newborn a high carb, high fat solid food meal right away?
b/c they lack sufficient pancreatic amylase (no starches)
also, they aren't good @ absorbing fats (don't give them high fat milk)
blood glucose is unstable (liver not fully fcnl)
What is a newborn really good at utilizing in terms of metabolism?
about 90% of them are utilized in the formation of body proteins
What are some substances that are necessary to have in a mother's well-balanced diet so that it can be transferred to the kid?
Why is it important for a newborn to have sufficient calcium & vitamin D?
b/c of the rapid ossification of bones in a newborn
if theses are insufficient-->rickets.
Why is it important for a newborn to have sufficient iron?
**could get anemia @ 3 months if the mom doesn't have enough.
**if mom does have enough, good for first 6 months of life.
What is a common reason for infants to get vitamin C deficiency?
maybe mom feeds them cow's milk. Low in Vit C--may need to supplement this with juice.
What is the metabolic rate of a neonate compared to that of an adult?
2X that of an adult--why they need so many calories
Why does a baby's body temperature often drop after birth before it recovers?
well they have a low body mass...& they have a relatively large surface area. Perfect recipe for temperature loss.
Describe the immunity issues of a baby? When do they start getting allergies?
maternally inherited immunity lasts for six months & protects against major diseases (don't need vaccinations before 6 mo)
allergies begin to appear after 6 mo when the baby starts producing their own antibodies.
What can happen if a mom has excess androgenic hormones?
female children may experience masculinization of their sex organs (hermaphrodites)
What can happen if a mom has a prolactinoma or something & has excess sex hormones or prolactin?
neonatal breast development
What is the problem with a diabetic woman experiencing hyperglycemia while pregnant?
this is problem b/c then the fetus may experience hypertrophy & hyper function of their islets of Langerhans
If a mother is experiencing hypothyroidism or hyperthyroidism or insufficient secretions from her adrenal gland or excessive secretions from her adrenal gland...what will the baby do?
the baby's body will compensate for the deficiency or excess.
If mom has hyperthyroidism: baby will have hypo secretion of her thyroid gland. And so on & so forth.
What can happen to a fetus if it experiences hypothyroidism?
poor bone growth & mental retardation
What are the main issues seen in babies born prematurely?
respiratory distress syndrome
GI problems with absorption: intolerant of fats, needing diets high in calcium & Vit D
Liver even more nonfunctional: hypoproteinemic edema
Even greater difficulty regulating body temp: need to use incubator
Should babies that are born prematurely be given oxygen?
perhaps, but in a very closely regulated way.
When O2 is high, the blood vessels in the retina are inhibited from further growth. If a child is suddenly taken off of O2, the blood vessels will rapidly grow in the vitreous humor & block the passage of light to the retina. Called retinopathy. Blindness may result from unchecked oxygen therapy.
What is another name for respiratory distress syndrome? What characterizes this disorder? What is the ultimate cause of it, though?
Hyaline Membrane Disease
large quantities of a fluid with proteins (looks like plasma) in the alveoli
ultimately caused by a lack of surfactant secretion
**prevents gas exchange-->babies can't get adequate oxygen
When do baby's lungs start secreting surfactant in utero?
1-3 months before birth
secreted by Type II Alveolar Cells
If RDS progresses, what horrific things can result?
pulmonary emphysema (alveolar damage)
What are the risk factors for developing RDS?
second born twin
lecithin/sphingomyelin ratio < 2 in the amniotic fluid
What are the clinical features of RDS?
tachypnea (rapid breathing)
chest x ray shows "ground glass" appearance (clogged alveoli)
If you use oxygen therapy in a baby w/ RDS...what are some negative things that might result?
bronchopulmonary dysplasia (scarring of the alveoli)
When is the APGAR scoring conducted on newborns? What are the intervals @ which it is performed?
immediately after birth
@1 min, 5 min & if something is wrong: 10 min
What are the 5 features that are evaluated w/ the APGAR score? What is each one rated?
G: grimace, reflexes
A: appearance (skin color)
Summed up to give a max score of 10.
What is considered a normal score? What is considered a moderate score? What is considered a low & dangerous score?
Normal: 7-10 (10 is max)
Moderate: 4-6 (resuscitative measure may need to be done)
Low: 1-3 (immediate resuscitation required)
What would an activity score of 0, 1, 2 mean?
0: no activity at all
1: arms & legs flexed
2: active movement
What would a pulse of 0, 1, 2 mean?
0: pulse absent
1: pulse less than 100 bpm
2: pulse greater than 100 bpm
What would a grimace of 0, 1, 2 mean?
0: no response, no reflex
2: sneeze, cough, pull away
What would an appearance score of 0, 1, 2 mean?
0: blue-grey pale all over
1: normal, maybe abnormal in extremities
2: normal everywhere
What would a respiration score of 0, 1, 2 mean?
0: no respiration
1: slow, irregular respiration
2: good respiration, crying
Describe the difference in the height growth of boys & girls. What ultimately stops someone from getting taller?
both usu have grown 10 inches in first year & 20 inches in second year
@ puberty: huge increase in growth w/ both genders
Girls rich their max height before boys, however.
Height determined by the fusing of epiphyseal plates.