Cardiovascular Overview Flashcards
Where path does fetal blood to the brain take?
Where path fetal blood to the rest of the body take?
To the brain: Ductus venosus* -> IVC -> RA -> foramen ovale -> aorta -> brain.
To the body: SVC -> RA -> RV -> pulmonary artery -> ductus arteriosus -> descending aorta
*correctedd
5 modifications found in fetal circulation?
Ductus venosus Foramen ovale Ductus arteriosis Increased pulmonary resistance Decreased RV dialstolic compliance
Where path does fetal blood to the brain take?
Where path fetal blood to the rest of the body take?
To the brain: Ductus venosus* -> IVC -> RA -> foramen ovale -> aorta -> brain.
To the body: SVC -> RA -> RV -> pulmonary artery -> ductus arteriosus -> descending aorta
*corrected
What are 2 signals that lead to the closure of the ductus arteriosus?
Increased O2 concentration.
Withdrawal of PGE2.
(this change takes a little longer, and is usually done by 4 days)
What’s cardiac output?
Liters blood pumped / minute
What’s the cardiac index?
Cardiac output / body surface area.
What’s the left ventricular ejection fraction (LVEF)? Importance?
LVEF is fraction of blood present at end-diastole (filling) that gets ejected in systole. Normal is 55-70%. It’s a crude measure of LV contractile performance.
Definition of compliance?
delta V / delta P
What’s the relationship between pressure and velocity?
Bernoulli’s: P + 0.5(rho)v^2 = Constant
What’s LaPlace’s principle?
Tension = pressure x radius
For a bigger vessel, the wall needs to be stronger to withstand a given pressure.
How is radius related to flow?
Flow is proportional to r^4, so small differences in radius make huge changes in flow.
(Poiseulles - also talks about viscosity)
What is Reynold’s principle used for?
For determining at what velocity non-linear flow (a murmur) will occur.
How are flow, pressure, and resistance related?
Q (flow) = P / R
