Lifespan Flashcards
foramen ovale
between r and l atria (bypasses the r ventricle) so that most blood is going to body through l ventricle and not to lungs (no need)
after birth, because of the change in pressure in the atria, (L>R) it closes
ductus arteriosus
connects pulmonary artery to aorta (so blood that goes to the RV instead of through foramen ovale gets shunted to the aorta to go to the body)
umbilical vein
carries oxygenated blood to baby
umbilical artery
carries unoxygenated blood to mom
tricuspid atresia
R to L defect, cardiac shunt
tricuspid valve does not form, so wall btwn RA and RV
all blood goes through LV, fine until baby has to breathe on its own
baby will most likely die unless other defects (ventricular septum defect) allows some blood to go to the lungs
tetralogy of fallot
R to L
- ventricular septum defect–doesnt completely form
- something wrong with infindibulum of RV–blood can’t get out
- aorta comes off where septum should have been–mal positioned RV blood goes to aorta, mixes with LV blood
- as a consequence, RV continues to work harder than it should, hypertrophies
patent ductus arteriosus (PDA)
DA does not close, remains functioning
since aorta has a higher pressure, blood flows back into the pulmonary artery and bypasses the lungs twice
not enough blood gets to the periphery
the baby is hypoxic but not hypoxemic
atrial septal defect
less costly/consequential than ventricular
ventricular septal defect
communication between L & R ventricle, blood flows from L into R because of the pressure difference and bypasses the lungs again
hypoxic but not hypoxemic
coarctation of the aorta
narrow aorta–usually right at the site of the DA (over-fibrosing)
causes muscle tone below the arms to be very poor, low blood flow to the organs
first breath changes in pulmonary system
- changes in ventilation
- changes in respiration: gas exchange
- changes in blood flow
- changes in cardiac chamber pressure
changes in ventilation after first breath
movement of fluid out of airspaces into lymphatics
surfactant present, opens alveoli
breathing pattern begins: uncoordinated
changes in blood flow after first breath
umbilical vessels close due to cold and lack of oxygen
no placental circulation causes immediate fall of blood volume on the right and decreased pressure in IVC and RA
dereased blood flow resistance because of oxygen in the lungs
increased blood return from lungs via pulmonary vein to LA
increased peripheral vascular resistance due to systemic oxygenation
changes in cardiac chamber pressures due to first breath
more blood going to LA, increased La pressure and decrease RA pressure, close foramen ovale
when does the embryo have a 4 chambered heart
7 weeks
