Ultrasound Physics - 18\hemodynamics Part I

Front 1

The study of blood moving through the circulatory system

Back 1

Hemodynamics

Front 2

This indicates the volume off blood moving during a particular time; it answers the question, "How much?"

Back 2

Flow
Volume Flow Rate

Front 3

Flow is reported in what units?

Back 3

Any volume divided by time
(L/min, ml/s, etc)

Front 4

This indicates the speed of a fluid moving from one location to another; it answers the question, "How fast?"

Back 4

Velocity

Front 5

Velocity is reported in what units?

Back 5

Any distance divided by time
(cm/s, m/min, etc)

Front 6

The following are forms of what?
- pulsatile
- phasic
- steady

Back 6

Flow

Front 7

This occurs when blood moves with variable velocity resulting from cardiac contraction (ex: arterial circulation)

Back 7

Pulsatile Flow

Front 8

This occurs when blood moves with a variable velocity resulting from respiration (ex: venous circulation)

Back 8

Phasic Flow

Front 9

This occurs when blood moves at a constant velocity (ex: venous circulation when breathing stops for a moment)

Back 9

Steady Flow

Front 10

What kind of flow exists when flows are aligned and parallel

Back 10

Laminar Flow

Front 11

The following are two forms of what?
- Plug Flow
- Parabolic Flow

Back 11

Laminar Flow

Front 12

This type of laminar flow occurs when all of the layers and blood cells travel at the same velocity

Back 12

Plug Flow

Front 13

This type of laminar flow occurs when velocity is highest in the center of the lumen and weakest at the vessel wall

Back 13

Parabolic Flow

Front 14

Is plug flow and parabolic flow a normal finding?

Back 14

Yes

Front 15

What kind of flow exists when chaotic flow pattern - in many directions and many velocities - are present?

Back 15

Turbulent Flow

Front 16

Turbulant Flow converts flow energy into other energy forms such as ___ and ___

Back 16

Sound & Vibration

Front 17

Sound associated with turbulent flow is called a ___

Back 17

Bruit
Murmur

Front 18

Vibrations associated with a turbulent flow is called a ___

Back 18

Thrill
Palpable Murmur

Front 19

Blood flows when the total fluid energy at one location differs from the total fluid energy at another location. What is this difference in energy called?

Back 19

Energy Gradient

Front 20

Which statement is more precise?blood flows due to a pressure gradient or blood flows due to an energy gradient

Back 20

Blood flows due to an energy gradient

Front 21

The following are forms of what?
- kinetic
- pressure
- gravitational

Back 21

Energy

Front 22

This form of energy is associated with a moving object. It is determined by the object's mass and it's speed

Back 22

Kinetic Energy

Front 23

This form of energy is a form of stored or potential energy, which has the ability to perform work

Back 23

Pressure Energy

Front 24

This form of energy is a form of stored or potential energy that is associated with any elevated object.

Back 24

Gravitational Energy

Front 25

How is energy imparted to blood?

Back 25

LV contraction during systole

Front 26

As blood flows throughout the body, name three ways its energy is lost

Back 26

1. Viscous Loss
2. Frictional Loss
3. Inertial Loss

Front 27

This describes the thickness of a fluid

Back 27

Viscosity

Front 28

More energy is lost with the movement of (high or low?) viscosity fluids.

Back 28

High Viscosity

Front 29

The percentage of red blood cells (and other cellular matter) in the blood is called what?

Back 29

Hematocrit

Front 30

What is the normal hematocrit level?

Back 30

45%

Front 31

What happens to blood viscosity if the hematocrit level drops (anemia)?

Back 31

With lower hematocrit levels, blood has reduced viscosity

Front 32

This form of energy loss occurs when flow energy is converted to heat as one object rubs against another

Back 32

Frictional Energy Loss

Front 33

This form of energy loss occurs when blood overcomes its own internal stickiness

Back 33

Viscous Energy Loss

Front 34

This form of energy loss occurs when the speed of a fluid changes (regardless of whether it accelerates or decelerates)

Back 34

Inertial Energy Loss

Front 35

What form of energy loss occurs at these three events:
- pulsatile flow
- phasic flow
- stenosis

Back 35

Inertial Energy Loss

Front 36

In a stenotic vessel, where does maximal velocity occur?

Back 36

At the vessel's narrowest point

Front 37

In a stenotic vessel, where does reduced velocity occur?

Back 37

Beyond the vessel's narrowest point

Front 38

A narrowing in the lumen of a blood vessel is called what?

Back 38

Stenosis

Front 39

How does stenosis effect flow direction?

Back 39

Flow direction can change (turbulence) as blood flows through the narrowing

Front 40

How does stenosis effect flow velocity?

Back 40

Velocity increases flowing into the narrowing and decreases past the narrowing

Front 41

How does stenosis effect pressure?

Back 41

Increased pressure at the narrowing, decreased pressure past the narrowing (pressure gradient)

Front 42

How does stenosis effect flow pattern (pulsatile, phasic, steady)?

Back 42

Pulsatile flow pattern converts to a steady flow pattern