Physio- adaptations to pregnancy Flashcards
what are teh blood glucose changes in the mother in pregnancy?
decreased blood glucose early, and insulin resistence later
what mediates the blood glucose changes( increased blood glucose on ingestion, and exaggerated insulin response)?
human placental lactogen
what does increase in estrogen ( DHEAS) LEAD TO?
increase in excitabiluyt ( gap junctions in the myometrium)–> prostaglandin synthesis, increase in oxytocin receptors, increase contraction of the uterus ( increased oxytocin released from pituitary
the release of what hastens the maturation of the respiratoy system?
CRH–> ACTH
what is needed to make milk?
estrogen and progesterone are needed for prolactin to make milk
what promotes full lobuloalveolar development of the mamarry glands?
prolactin from the pituitary
what does prolactin cause after birth?
fomration of milk, and secretion into the ducts
what does oxytocin do after birth?
contraction of myoepithelial cells, ejection of milk out of the nipple
what si the function of the placenta?
gas exchange, nutritional, homeostatic
what is the casue of slower diffusion in the embryo?
increase in distance that the gas has to go to diffuse ( 3.5 micrometers vs .6)
what si the net effect of the increased distance for gas exchange, and the difference in change of Pressure?
difusion of O2 at the placenta is reduced
what aer teh blood gases of a fetus compared to mom?
PaO2 = 35 (HbF high affinity for O2)
PaC02 higher- mom has respiratory alkalosis
ph is a little lower in the fetus ( 7.37)
what do synaptic formations in the brain depend on?
genetics and experience
when do movements of the fetus become stereotypical?
third trimester
what sit eh process of synapses?
too many are formed, thus pruning is needed, and this is done by experience ( occurs late trimester, and after birth)
what happens on EEG in the last trimester?
increased voltage
what is teh respiratory generator in the fetus?
pre-botzinger
what aer teh two breathing forms of fetus?
paradoxical ( abs out, ribs in)
gentle ( abs and ribs out)- occurs during REM
what are the characteristcis of the fetal lungs?
high elastin levels= low compliance
what is needed for physcial growth of the lungs?
IGF-2 and GH
do peripheral chemoreceptors effect breathing? are centrl chemo receptors functional?
NO, and NO
what happens to breathing during times of fetal hypoxia?
respiration is supressed
what si the action of the mechano receptors on respiration?
STRONGLY inhibited- this means anything that increases the work of breathing, will cease breathing
what is the initial compliance of the lung at birth?
LOW, due to low lung volume
what has to happen with the mechano receptors after birth?
must become less inhibitory
what is teh oxygenation of the portal vein, and ductus vebnosis? what about the ascending aorta/head?
80% and 65%
where is blood preferantially directed to from the inferior vena cava?
heart and head, because it is oxygenated from the placenta
where is blood from the superior venacava sent?
to the placenta to get oxygenated
what is the cardiovascualr response to stimulus of chemo receptors?
vasoconstrics all but heart, brain and placenta, and also the heart becomes bradycardic
what is the fetal GFR?
50 ( about half of the normal adult GFR)
what is the result of the fetal inadequate renal function?
loss of Na+, loss of glucose and amino acids, lack of ability to concentrate or dilute the urine
why is the GI function of absorption limited in utero?
due to the lack of intestinal flora
what is the main function of the liver in utero?
to store glycogen and iron
what is the main growth hormone of the fetus?
insulin
