Fetal Physiology Flashcards
(20 cards)
what happens to the fetal brain between weeks 12 and 20?
neurons migrate from ventricular zone to the developing cortex and deep nuclei where they will reside for life
when is the highest period of neural proliferation?
weeks 8-15
what might occur if brain growth is reduced/increased between weeks 8-15 and what factors may cause this?
microencephaly (caused by alcohol or radiation) or megalocephaly (caused by G/T2DM)
what 4 processes occur in the development of fetal brain?
neurogenesis, synaptogenesis to connect new neurons, apoptosis of incorrect neurons, synaptic pruning to remove incorrect connections
development of newborn brain from embryonic brain involves massive _______, _________ of neurons and ______, and organisation of _____ __________
proliferation, differentiation, glia, brain regions
compare fetal arteries and veins and describe the blood they take and the direction it travels
fetal arteries take deoxygenated/nutrient poor/waste contaminated blood towards placenta, vein takes oxygenated etc blood to baby
when does O2 surge in fetal circulation and why?
O2 surges in T2 since the spiral arteries TB plug is removed
describe umbilical vein pathway
vein carries oxygenated blood from placenta travelling to large ductus venosus and smaller portal sinus, ductus venosus takes blood directly to the inferior vena cava whereas the portal sinus takes it to the liver
what does the ductus venosus become once closed?
ligamentum venosus
what is the purpose of the foramen ovale and where is it located?
located bw the right and left atria, allows blood to bypass the right ventricle and pulmonary circuit
what does the foramen ovale become once closed?
fossa ovalis
what is the purpose of the ductus arteriosus?
the ductus arteriosus allows blood to bypass the lungs as it flows from the pulmonary artery into the DA -> aorta and into circulation
what does the ductus arteriosus become once closed?
ligamentum arteriosum
describe internal iliac function in fetus
internal iliac branches off and has artery taking blood back to placenta
what does internal iliac placental branch become after birth?
medical umbilical ligament
describe the urachus
forms from embryonic allantois and is a functional way to remove urine
why does fetal heart need to be fast?
placenta has very low resistance due to branching therefore increased HR ensures blood can be pumped well enough to maintain enough pressure for circulation
when does fetal heart roughly become ready for birth?
32K, cells switch to adult phenotype
compare fetal kidneys over gestation
pronephros: first type, very primitive, minimal urine output
mesonephros: slightly more developed, start from 5K and degenerates around 11K
metanephros: final kidney, starts 5K but still relying on meso, releases certain compounds in urine to help develop lungs and GIT, nephrogenesis until 36K therefore prem babies will have less nephrons
what is the long term effect of being born with fewer nephrons?
HTN will occur at an earlier age
