Physics Ch. 18 Hemodynamics

Front 1

Normally, what happens to venous flow in the legs during inspiration?

Back 1

Venous flow in the legs decreases during inspiration

Front 2

_______ indicates the volume of blood moving during a particular time

Back 2

Flow

Front 3

the speed or swiftness of a fluid moving from one location to another

Back 3

Velocity

Front 4

3 basic forms of blood flow

Back 4

Pulsatile, Phasic, and Steady

Front 5

Pulsatile

Back 5

when blood moves with a variable velocity. appears with arterial circulation

Front 6

Phasic Flow

Back 6

blood moves with variable velocity. accelerates and decelerates with respiration. Appears with venous circulation

Front 7

Laminar Flow

Back 7

means layer. Commonly found in normal physiology.

Front 8

Plug flow

Back 8

type of laminar flow. When all layers of blood flow at same velocity

Front 9

Parabolic

Back 9

type of laminar flow. bullet shaped. Velocity is highest in the center of the vessel

Front 10

Reynolds Number

Back 10

predicts whether blood flow is laminar or turbulent. 1,500-2,000

Front 11

Turbulent Flow

Back 11

chaotic flow patterns in many different directions and speeds. Often associated with pathology.

Front 12

Sound associated with turbulent flow

Back 12

murmur (heart), & bruit (vessel)

Front 13

Thrill

Back 13

VIBRATION associated with turbulence

Front 14

Energy Gradient

Back 14

when blood moves from regions of HIGHER energy to LOWER energy

Front 15

What provides energy to the circulating blood?

Back 15

the contraction of the heart during systole

Front 16

Kinetic Energy

Back 16

associated with a moving object. determined by object's MASS and SPEED. Heavy, swiftly moving objects have lots of kinetic energy

Front 17

Pressure Energy

Back 17

stored or potential energy. Creates flow by overcoming resistance

Front 18

Energy losses in Circulation

Back 18

1. Viscous loss
2. Frictional loss
3. Inertial loss

Front 19

Viscous Energy Loss

Back 19

Describes thickness of blood. More energy lost with high viscosity fluids. Units-Poise. determined by Hematocrit

Front 20

Frictional Energy Loss

Back 20

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

Front 21

Inertial Energy Loss

Back 21

Energy lost when speed of fluid changes.Tendency of a fluid to resist changes in velocity

Front 22

Stenosis

Back 22

narrowing of the lumen in a vessel.

Front 23

Where is the highest velocity in a stenotic vessel?

Back 23

where the vessel is most narrow

Front 24

Pressure Gradient across stenosis

Back 24

Post-stenotic pressure is lower than the pressure before the stenosis

Front 25

Effects of Stenosis

Back 25

-loss of pulsatility
-change in flow direction
-post-stenotic turblence
-increased velocity where vessel narrows

Front 26

Bernoulli's Principle

Back 26

describes relationship between VELOCITY and PRESSURE. the sum of kinetic energy and pressure energy remains constant

Front 27

Venous Hemodynamics

Back 27

have low pressure normally. As venous pressure increases the vessel becomes more round

Front 28

Hydrostatic Pressure

Back 28

the weight of blood pressing on a vessel when measured above or below heart level. mmHg.

Front 29

When a person is supine, what is the hydrostatic pressure?

Back 29

the Hydrostatic pressure is 0, everywhere

Front 30

circulatory pressure + hyrdrostatic pressure=

Back 30

measured pressure.