Hemodynamics

Question 0

What are the two kinds of flow?

Answer 0

forward and reverse flow

Question 1

What is hemodynamics?

Answer 1

literally “blood movement”

the study of blood FLOW or the circulation

Question 2

Forward flow is _____the line, reverse flow is ______the line

Answer 2

Above

Below

Question 3

What is circulation?

Answer 3

flow of blood through a closed system

Question 4

What makes up the arterial system?

Answer 4

multibranched elastic conduit that carries blood away from the heart

Question 5

What is energy?

Answer 5

blood flow is in motion

ability to do work

conservation of energy - energy is never lost only converts to another form

Question 6

What is potential energy?

Answer 6

resting energy (static)

Question 7

What is kinetic energy?

Answer 7

motion energy (dynamic)

Question 8

What is power?

Answer 8

concentration of force per unit area

force behind fluid flow

Question 9

What is total energy?

Answer 9

kinetic + static

Question 10

the pressure exerted by a fluid due to its weight or force per unit area is called?

Answer 10

hydrostatic pressure

Question 11

What is the energy or pressure gradient?

Answer 11

pressure difference in order for blood to move

flow is from high to low pressure

gradient = difference

Question 12

Pressure has to build in the left ventricle before it can eject blood out of the aortic valve into the aorta, true or false?

Answer 12

true

Question 13

What is stroke volume?

Answer 13

the AMOUNT (volume) of blood ejected

equal to the DIFFERENCE between end diastolic volume and end systolic volume

Question 14

pressure is necessary to….

Answer 14

maintain flow

Question 15

the greater the pressure gradient, the ______the flow rate

Answer 15

greater

Question 16

What is the energy gradient?

Answer 16

determines flow

Question 17

what causes loss in flow?

Answer 17

friction

resistance

Question 18

What are some things that can cause friction/resistance?

Answer 18

clot

thrombus

tumor

Question 19

The greater the resistance the ______the flow

Answer 19

lower

Question 20

what is the sign for the pressure gradient?

Answer 20

triangle ^P

Question 21

What is viscosity?

Answer 21

THICKNESS — resistance to flow

Question 22

What are the different types of flow?

Answer 22

laminar flow - normal - layers with the highest velocities in the center stream

parabolic - bullet shape

plug - SAME velocity

these are all NORMAL

Question 23

What is Poiseuille’s Law?

Answer 23

in an ARTIFICIAL SYSTEM how the flow changes

the smaller the more pressure needed

the thicker the slower the flow

how much pressure is needed if you change pressure, length or viscosity

Question 24

What are the three primary factors that determine the resistance to blood flow within a single vessel

Answer 24

finish slide 28

Question 25

In Poiseuille's Law, what are the direct and indirect relationships?

Answer 25

Direct: pressure increases, flow rate increases diameter increases, flow rate increases Indirect: length increased, flow rate decreased viscosity increases, flow rate decreases resistance increases, flow rate decreases

Question 26

What accounts for about half of the resistance in systemic circulation?

Answer 26

resistance of the ARTERIOLES

Question 27

What does Bernoulli's principal say about pressure?

Answer 27

velocity and pressure are inversely related high velocity = low pressure low velicity = high pressure *relationship in a stenosis* high velocity with low pressure

Question 28

look at slide 34...what is the diagnosis?

Answer 28

spectral broading....LRA stenosis

Question 29

Slide 35, recognize the difference flow patterns

Answer 29

peripheral resistance low resistance high resistance

Question 30

What happens to velocity and pressure when you have a stenotic vessel?

Answer 30

velocity increase pressure decreases

Question 31

What three things might you see on US if you have a stenotic vessel?

Answer 31

reduction in volume flow bruits spectral broadening slide 37 for picture

Question 32

What are the different types of laminar flow?

Answer 32

parabolic disturbed - flow breaks down plug - uniform speed or velocity

Question 33

What are the two kinds of turbulent flow

Answer 33

chaotic Eddies - flow is kind of like a tornado (ex: pseudoaneryusm)

Question 34

What is Reynolds number?

Answer 34

a number used to show turbulence if the number is above 2000, flow is turbulent

Question 35

increase in flow speed increases _________number, increase in vessel radius _______ reynolds number

Answer 35

reynolds number increases

Question 36

What is pulsatile flow?

Answer 36

non steady flow with acceleration and deceleration over the cardiac cycle

Question 37

What is the continuity rule?

Answer 37

flow rate must be constant proximal, at and distal to a stenosis

Question 38

flow speed ______at a stenosis and _______can occur distally

Answer 38

increases turbulence

Question 39

What is an occlusion?

Answer 39

blocked vessel - no flow

Question 40

what is bruits?

Answer 40

sound produced by turbulence - indicates a change in flow

Question 41

What is triphasic - high pulsatility?

Answer 41

sharp upstroke in systole - has three points flow reversal - resistance forward flow

Question 42

what is biphasic flow?

Answer 42

moderate pulsatility - goes up and down

Question 43

What is monophasic flow?

Answer 43

low pulsatility broad systolic peaks