CH 18 - Hemodynamics

Question 1

the study of blood moving through the circulatory system

Answer 1

hemodynamics

Question 2

flow / volume flow rate

Answer 2

indicates the volume of blood moving during a particular time
units - L/min

Question 3

velocity

Answer 3

speed of a fluid moving from one location to another

units - cm/s

Question 4

three basic forms of blood flow

Answer 4

pulsatile
phasic
steady

Question 5

type of flow that occurs when blood moves with a variable velocity

Answer 5

pulsatile flow

Question 6

blood has a variable velocity because of

Answer 6

cardiac contraction

Question 7

pulsatile flow commonly appears in the ___ circulation

Answer 7

arterial

Question 8

this type of flow also occurs when blood moves with a variable velocity, but because of respirations

Answer 8

phasic flow

Question 9

phasic flow often appears in ___ circulation

Answer 9

venous

Question 10

occurs when a fluid moves at a constant speed or velocity

Answer 10

steady flow

Question 11

steady flow is present in the venous circulation when ___

Answer 11

individuals stop breathing for a brief moment

Question 12

when the flow streamlines are aligned and parallel

Answer 12

laminar flow

Question 13

laminar flow is characterized by layers of blood that travel at …

Answer 13

individual speeds

Question 14

laminar flow patterns are normal or abnormal

Answer 14

normal

Question 15

laminar flow has 2 terms

Answer 15

plug flow

parabolic flow

Question 16

occurs when all of the layers of blood cells travel at the same velocity

Answer 16

plug flow

Question 17

parabolic flow

Answer 17

bullet shaped profile

velocity is highest in the center of the lumen and gradually decreases at the walls of the vessel

Question 18

Reynolds number

Answer 18

predicts whether flow is laminar or turbulent

laminar is less than 1500

Question 19

flow that is characterized by chaotic flow patterns in many different directions and many speeds

Answer 19

turbulent flow

Question 20

turbulence is often associated with a ___

Answer 20

pathology

Question 21

sound associated with a turbulence

Answer 21

murmur

bruit

Question 22

vibration associated with turbulence

Answer 22

thrill

Question 23

a palpable murmur that you can feel with your fingertips

Answer 23

thrill

Question 24

Reynolds number of turbulent flow

Answer 24

greater than 2000

Question 25

why does blood move from one location to another

Answer 25

energy gradient - moves from high to low energy

Question 26

what event provides energy to the circulating blood

Answer 26

systole

Question 27

forms of energy in blood

Answer 27

kinetic pressure gravity

Question 28

kinetic energy is associated with a moving object | has 2 factors

Answer 28

an objects mass (high mass, high kinetic energy) | the speed at which it moves (high speed, high kinetic energy)

Question 29

pressure energy is a form of ___ or ___ energy

Answer 29

stored or potential energy

Question 30

a form of stored or potential energy associated with any elevated object

Answer 30

gravitational energy

Question 31

energy is lost in 3 ways in curculation

Answer 31

viscous loss frictional loss inertial loss

Question 32

the thickness of a fluid

Answer 32

viscosity

Question 33

viscosity units

Answer 33

Poise

Question 34

the percentage of blood made up of red blood cells

Answer 34

hematocrit

Question 35

how do we determine viscous energy loss in blood

Answer 35

hematocrit

Question 36

normal hematocrit level

Answer 36

45%

Question 37

occurs when flow energy is converted to heat as one object rubs against another

Answer 37

frictional energy loss

Question 38

energy loss when speed of a fluid changes regardless of whether the fluid speeds up or slows down

Answer 38

inertial energy loss

Question 39

the tendency of a fluid to resist changes in its velocity

Answer 39

inertia

Question 40

inertial energy loss occurs during 3 events

Answer 40

pulsatile flow phasic flow stenosis

Question 41

velocity increases as the vessel widens/narrows

Answer 41

narrows

Question 42

narrowing in the lumen of a vessel

Answer 42

stenosis

Question 43

a type of turbulence downstream from the stenosis

Answer 43

post-stenotic turbulence

Question 44

describes the relationship between velocity and pressure in a moving fluid

Answer 44

Bernoulli's principle (states that the sum of kinetic energy and pressure energy remains constant)

Question 45

pressure-flow relationship

Answer 45

relationship between flow, resistance, and pressure gradient

Question 46

pressure gradient increases when

Answer 46

flow increases or when | resistance increases

Question 47

flow increases when

Answer 47

pressure gradient increases or | resistance decreases

Question 48

Ohm's Law

Answer 48

voltage = current x resistance

Question 49

fluids

Answer 49

pressure flow resistance

Question 50

electricity

Answer 50

voltage current resistance

Question 51

electrical resistance units

Answer 51

ohms

Question 52

resistance vessels in the circulatory systems are called

Answer 52

arterioles

Question 53

what is the typical resistance of veins

Answer 53

low resistance vessels

Question 54

how do veins adapt to increased inflow during periods of exercise?

Answer 54

the CSA of the vessel changes to oval and then round to accommodate a large volume increase

Question 55

pressure related to the weight of blood pressing on a vessel measured at a height above or below heart level

Answer 55

hydrostatic pressure | units - mmHg

Question 56

clinical significance of hydrostatic pressure

Answer 56

when taking a patients blood pressure

Question 57

supine

Answer 57

laying flat on back

Question 58

during supine position, the hydrostatic pressure is

Answer 58

zero everywhere