Arterial Hemodynamis Class 8 Unit 16 Flashcards
Systolic velocity is ________ than diastolic velocity
Higher
Why is systolic velocity higher than diastolic velocity?
Because of the heart pumping in systole and flowing moving on it’s own momentum in diastole .
Does systolic velocity increase or decrease, as the blood flows to the ankles?
It decreases.
When viewing in ultrasound of the peripheral arterial flow, what characteristic is usually found within the waveform?
Peripheral arterial flow is pulsatile, due to the pumping of the heart.
Doppler velocity waveforms demonstrate what?
Demonstrate velocity changes, throughout the cardiac cycle
In the peripheral arteries (le and ue), how is the velocity pattern demonstrated on doppler?
Velocity pattern is forward in systole, with a sharp upstroke, and narrow peak, followed by a short reversal of flow. (Looks more triaphasic )
In the normal le and ue, flow reversal is primarily due to what?
The resistance of the distal vascular bed that the artery is feeding.
In normal le and ue arteries, what is the resistance controlled by?
Arterioles
During exercise, what happens to the arterioles?
Arterioles open, which causes the resistance to decrease, and increases the flow needed for the muscles to work.
What determines the diastolic portion of the velocity waveform?
Resistance of distal vascular bed
Is there a high or low resistance, in the vessels feeding the brain, kidney, and liver?
Low resistance
Peripheral arteries normally _________ resistance at rest.
High
Why do arterioles open?
to reduce resistance and increase flow as needed.
When do arterioles open?
- During a proximal obstruction in the artery. -inflammation -exercise -anything that may cause decreased peripheral resistance.
Normal mean velocities in the peripheral arteries (These are not criteria, just average velocities)
