URR Hemodynamics Flashcards
What is the cycle of Systemic Circulation in the body ?
lt vent -> Ao -> arterioles -> capillaries -> venules -> veins -> IVC/SVC -> rt atrium
What is the cycle of Pulmonary Circulation in the body?
rt vent -> pulmonary A -> lungs -> pulmonary veins -> lt atrium
oxygen saturation is highest where in the heart?
pulmonary vein
oxygen saturation is lowest where in the heart?
IVC/SVC
what are the only arteries to carry deoxygenated blood?
pulmonary artery
what veins are the only veins to carry oxygenated blood?
pulmonary veins
what happens during systole in the cardiac pump?
(contraction) lt vent pressures increase rapidly to exceed aortic pressure and push bolus of blood into the arteries
what happens during diastole in the cardiac pump?
(relaxation) lt vent pressures decrease rapidly and lt vent refills with blood from the lt atrium
the normal heart rate is?
60-100 bpm
what is bradycardia?
< 60 bpm
what is tachycardia?
> 100 bpm
the heart pumps an average of how much blood into the Aorta with each contraction?
70ml
systemic pressure is greatest at the what?
heart
arterioles are responsible for what?
regulating resistance in the tissues
capillaries are responsible for what?
perfusion of the surrounding tissues and the exchange of nutrients and waste products between the blood and tissues
what is kinetic energy?
energy of motion
what is potential energy?
stored energy of motion
what is gravitational energy?
stored energy related to elevated position
kinetic energy is reduced in blood vessels due to what 3 factors?
-viscosity
-friction
-inertia
what is viscosity?
thicker blood moves slower
what is friction?
layers of blood sliding against each other, energy lost in form of heat
what is inertia?
energy lost when speed of blood changes
name at least 4 factors affecting blood flow?
-cardiac function
-peripheral resistance
-vessel compliance
-tone of vasc muscle
-vasoconstriction
-vasodilation
-viscosity
-exercise
-autoregulation
what is resistance?
determines the rate of flow in the arteries
what is resistance regulated by?
arterioles
if you increase viscosity, what happens to resistance?
increases
if you increase vessel length, what happens to resistance?
increases
if you increase the vessel radius, what happens to resistance?
decreases
if you increase resistance, what happens to blood flow?
decreases
if resistance increases, what happens to pressure?
decreases
what happens to resistance prox to a stenosis?
increases
what happens to resistance distal to a stenosis?
decreases
what is the equation for resistance?
8nL/ pie(r)^4
n= blood viscosity
L=length of a blood vessel
r=radius
what is the Poiseuilles Equation for?
-demonstrates relationship between flow volume and resistance
-used to describe how much fluid (blood) moves through an artery
in poiseulles equation, small changes in vessel radius cause the most significant changes in what?
flow
-vessel length and viscosity area constant, increase in either one will cause increase in resistance
equations for flow volume?
(Q) = (P1-P2) pie(r)^4/ 8nL
P= pressure
n= blood viscosity
L=length
r= radius
or
(Q) = (P1-P2)/R
P=pressure
R= resistance
what is the bernoulli effect?
-when fluid flows at a constant velocity from 1 point to another, energy remains constant
-if pressure changes, velocity changes
what is the equation for bernoulli effect?
triangle(Pressure)=4V^2
pressure is highest in which part of the heart?
lt vent
-increase in systole, decrease in diastole
flow volume is always proportional to what?
pressure
-increase volume = increase BP
