Hemodynamics

Question 1

_____ is the study of the forces and motion of blood flow
or of blood circulation

Answer 1

hemodynamics

Question 2

Blood flows due to _____ in the heart and _____ in the veins, returns to heart via _____

Answer 2

high pressure, low pressure, leg muscle contract

Question 3

how does blood flow? from what to what?

Answer 3

Heart, Arteries, Arterioles, Capillaries, Venules, Veins back to lungs

Question 4

what does this show?

Answer 4

how blood flows

Question 5

What are the 4 chambers of the heart?

____ create high pressure

____ have low pressure so blood returns

Answer 5

Right atrium. left atrium, Right ventricle, Left ventricle

Ventricles, Atria

Question 6

what returns blood to the Rt Atrium?

what does the superior vena cava drain?

inferior vena cava?

Answer 6

venous system

arms and head

abdomen and legs

Question 7

how does the arterial system flow?

Answer 7

Pumped via left ventricle (LV)
Creates high pressure
Blood travel via aorta to systemic arterial system
Returns to heart via systemic veins (IVC and SVC), into right atrium

Question 8

how does the pulmonary arterial system work?

Answer 8

Pumped via right ventricle (RV)
Creates high pressure
Blood travel via pulmonary artery to lungs
Returns to heart via pulmonary veins, into left atrium

Question 9

we have ~ ____ liters of blood in our body. it is circulated at appro ____ L/min. which means our entire blood volume is circulated every ___.

Answer 9

5, 5, minute

Question 10

what takes the shape of their container?

what are 2 examples?

Answer 10

fluid

gas and liquid

Question 11

what causes resistance to flow?

examples?

Answer 11

viscosity

“thicker”
Syrup is more viscous than water
Blood is “thicker” or viscous than water

Question 12

what does anemia cause?

Answer 12

lower viscosity, less RBC’s

Question 13

what does polycythemia cause?

Answer 13

higher viscosity, more RBC’s

Question 14

____ is the pressure blood exerts on vessel walls and
_____ is the energy of motion of blood

Answer 14

potential energy, kinetic energy

Question 15

____ is the difference in pressures which causes fluid to flow (pump, gravity…)

Answer 15

pressure gradient

Question 16

gravitational energy is described as ____________.

Answer 16

hydrostatic pressure

Question 17

blood always flows from ____ to ____

Answer 17

high pressure (heart pump), low pressure (venous system)

Question 18

increasing pressure gradiant cause ____ flow?

which will go faster?

Answer 18

increasing

bottom differenc eof 75mmHg as opposed to 25

Question 19

What is “flow”
Volume/amount of blood passing through a point per unit of time (mL/min)
Adult volumetric flow rate approximately 5000 mL/min (5 L/min)
Aka Cardiac output
Total blood volume circulates in approximately 1 min.

Answer 19

Volumetric Flow Rate (Q)

Question 20

____ is determined by
pressure difference (Pressure gradient )
resistance to flow

Answer 20

Volumetric Flow Rate (VFR)

Question 21

increase in pressure gradient = ____ VFR

increase in resistance = ____ VFR

what is the equation?

Answer 21

increased, decrease

VFR=pressure gradient/resistance

Question 22

increase reistance = ___ flow

resistance is affected by (3)…

when we exercise, resistance _____. how?

Answer 22

decreased

viscosity, tube length, radius

decreases - radius increases = increased flow = (heart works harder) higher pressure gradient

remember VFR = pressure gradient/resistance

Question 23

increased viscosity = _____ resistance = ___ flow

increased radius = ____ resistance = ___ flow

increased length = ___ resistance = ___ flow

Answer 23

increased, decreased

decreased, increased

increased, decreased

Question 24

____ demonstrates the relationship between pressure, volume of flow and resistance.

is aka radius to the 4th power, which demonstates radius has a significant affect on ___ and ____

Applies to steady flow and straight tubes, not situation in body

Useful in describing increasing and decreasing flows

Volumetric Flow(Q)= Pressure Gradient x 3.14r4
 8nL

Answer 24

Poiseuille’s Equation

resistance and flow

Question 25

Increased PG = ____ Flow Increased Diameter = ___ Flow Increased Length = _____ Flow variables in equation are

Answer 25

increase, increase, decrease radius and length

Question 26

According to Pousielles Equation, resistance increase is relative to the 4th power of the radius, so if you increase the radius 2x you will have ___ increase in flow? or is you decrease it to 1/2 you have ___ the flow

Answer 26

2˘4 = 16x 1/2 ˘4 = 1/16

Question 27

\_\_\_ determines ___ which determines \_\_\_ vasodilation = vasoconstricton =

Answer 27

radius, resistance, flow increase radius, decrease resistance, increase flow decrease radius, increase resistance, decrease flow

Question 28

at rest our legs are ___ b/c they don't need \_\_\_

Answer 28

vasoconstricted, much blood

Question 29

stenosis ____ radius, ___ resitance ___ flow infection causes vessels to \_\_\_\_, ___ radius, ___ resistance, ____ flow

Answer 29

decrease, increase, decrease vasodilate, increasing, decreasing, increasing to get blood to site to heal

Question 30

what types of flow are there? (4)

Answer 30

Plug Laminar Disturbed Turbulence

Question 31

\_\_\_ flow has the same flow speed throughout most vessel, Large vessels, Entrance of vessel

Answer 31

plug

Question 32

\_\_\_ flow Streamlines parallel Streamlines straight Fastest in center Slowest on outer edge Parabolic (define) -

Answer 32

parabolic sometimes word is interchanged w/ laminar. but not used often. it means speed on the side iis ~1/2 that in the center slowest speed = ½ maximum Nonparabolic laminar happens in body

Question 33

\_\_\_\_ flow means Streamlines are not straight Happens at Area of stenosis Bifurcation

Answer 33

disturbed also increased likelihood plaque will develop in these locations.

Question 34

\_\_\_\_\_ flow is Flow pattern is random and chaotic Different speeds and directions Eddies – area of flow reversal Occurs at a channel widening, after a stenosis What is Reynolds number? Where does this happen?

Answer 34

turbulent the point at which flow becomes spontaneously turbulent ~2000 \*there are places that widen naturally like the buldb of the aortic arch so can be result of natural, stenosis or aneurysm

Question 35

Density, Viscosity, Diameter and Speed determine the point at which flow becomes \_\_\_\_\_ the sound this gives off is \_\_\_\_ when tissue vibrates due to this it is called \_\_\_\_ where might this occur

Answer 35

turbulent bruit tissue bruit heart and proximal aorta