foetus and birth Flashcards
difference between foetal and postnatal circulation?
lungs not function in foetus
how oxygenated blood from the placenta is diverted during foetal development.
Why does foramen ovale stay open in foetus?
foremen Ovale - Oxygenated blood can move from left to right atrium and move directly towards the aorta and therefore brain
Why does Ductus arteriosus stay open in foetus?
carries blood from the pulmonary artery to the descending Aorta to supply the lower body and thus preserve the brain’s oxygen supply
Why does Ductus venous stay open in foetus?
Oxygenated blood bypasses the liver and moves towards the heart, not away from it
the changes that occur during the first breath?
O2 pressure rises- pulmonary dilation-R heart pressure falls - foramen ovale closes - venous blood - lungs - O2 pressure rises
ALSO when the placental circulation ceases, the L heart pressure rises which cause the foramen ovale to close.
SO closes as the LA pressure is greater than RA
Understand why foetal circulation may persist in newborns (most common problems).
1) Teralogy of Fallot - caused by unequal divison of trancus anteriosus resulting in stenotic pulmonary trunk - so baby don’t receive inadequate oxygenation (4 cardiac defects seen is Pulmonary atery stenosis, ventricular septal defect, overidding aorta (receiving blood from right verticle), right vetricular hypertrophy.
What Ig antibodies can carry diseases from the placenta to fetus?
IgG
What is the first indicator of pregnancy?
missed menstrural period
What increases the susceptibility to UTI in pregnancy?
Progesterone - relaxes smooth muscles in the bladder and ureter. When muscles relax, it increases the risk of UTI.
Where is human chorionic gondatrophin (hCG) produced in the first 3-5 weeks of pregnancy?
Trophoblast - this is the outer layer of the blastocyst, which produces hCG.
What is Zona Pelucida?
glycoprotein protective layer surrounding the plasma membrane of mammalian oocyte
What is a pluriblast?
it is the inncer cell mass within the blastocyst
How is the corpus luteum maintained?
maintained by the hCG
What is decidua?
maternal endometrium during pregnancy that becomes a maternal part of the placenta by the 10th week of pregnancy.
