Hemodynamics (Quiz 1)

Question 1

What part of the heart functions as a primer pump that increases the ventricular pumping effectiveness as much as 20%?

Answer 1

atria

Question 2

During ventricular systole, large amounts of blood accumulate in the R/L atria because of the closed _____ valves

Answer 2

AV

Question 3

As soon as systole is over, and the ventricular pressures fall again to their low diastolic values, the moderately increased pressures that have developed in the atria during ventricular systole immediately push the ___________ open and allow blood to flow rapidly into the ventricles

Answer 3

AV valves

Question 4

When the L ventricular pressure rises slightly above 80 mmHg, the ventricular pressures push the ____________ valves open

Answer 4

semilunar

Question 5

What percentage of blood in the ventricles is ejected at the end of diastole?

Answer 5

60%

Question 6

What are the AV valves?

Answer 6

tricuspid and mitral/bicuspid

Question 7

Which valves prevent back flow of blood from the ventricles to the atria during systole?

Answer 7

AV valves

Question 8

What are the semilunar valves?

Answer 8

aortic and pulmonary

Question 9

Which valves prevent back flow from the aorta and pulmonary arteries into the ventricles during diastole?

Answer 9

semilunar valves

Question 10

When do valves close?

Answer 10

when a backward pressure gradient pushes blood backward

Question 11

When do valves open?

Answer 11

when a forward pressure gradient forces blood in the forward direction

Question 12

T/F: the high pressure in the arteries at the end of systole cause the semilunar valves to snap close

Answer 12

true

Question 13

T/F: the velocity of blood ejection through the aortic and pulmonary valves is much greater than that through the much larger AV valves

Answer 13

true

Question 14

The edges of the ______________ valves are subjected to much greater mechanical abrasion than the ___________ valves

Answer 14

semilunar, AV

Question 15

Which valves are supported by chordae tendineae?

Answer 15

AV valves

Question 16

define murmur

Answer 16

any sound that isn’t predicted

Question 17

Which valve most commonly regurgs and causes murmurs?

Answer 17

mitral valve

Question 18

Which valves are constructed with a fibrous tissue?

Answer 18

semilunar

Question 19

When do we hear heart sounds through stethoscope?

Answer 19

when valves close

Question 20

What are the normal heart sounds?

Answer 20

lub dub

Question 21

When do we hear the lub sound?

Answer 21

closure of AV valve at the beginning of systole

Question 22

When do we hear the dub sound?

Answer 22

closure of the semilunar valves at the end of systole (S1/S2)

Question 23

Which sound is this?
-low pitch, longer sound

Answer 23

S1

Question 24

Which sound is this?
-shorter sound, higher frequency

Answer 24

S2

Question 25

If a microphone specially designed to detect low frequency sound is placed on the chest, the heart sounds can be amplified and recorded by a high speed recording apparatus. The recording is called a ____________________ and the heart sounds appear as waves

Answer 25

phonocardiogram

Question 26

define pressure

Answer 26

force over area

Question 27

define blood pressure

Answer 27

a force of blood over blood vessel surface area or in other words, force that the blood exerts on the surface area of the walls of blood vessels

Question 28

define blood flow

Answer 28

quantity of blood that passes a given point in the circulation in a given period of time

Question 29

total blood flow should always equal....

Answer 29

cardiac output

Question 30

The overall blood flow in the total circulation of an adult person at rest is about 500ml/min. This is called the _______________ because it is the amount of blood pumped into the aorta by the heart each minute

Answer 30

cardiac output

Question 31

Blood flow through a blood vessel is determined by 2 factors. What are they? test q

Answer 31

1) pressure difference/gradient 2) vascular resistence note: these are independent factors, can work together or alone

Question 32

What pressure does the aorta have?

Answer 32

80mmHg to maintain pressure gradient

Question 33

Which part of the heart has the highest pressure?

Answer 33

aorta

Question 34

What in the CV system has the largest pressure drop?

Answer 34

arterioles

Question 35

Which part of the heart has the lowest pressure?

Answer 35

vena cava

Question 36

What are the 2 devices to measure blood flow?

Answer 36

1) electromagnetic flowmeter 2) ultrasonic doppler flowmeter

Question 37

What is blood flow velocity?

Answer 37

distance traveled in certain amount of time

Question 38

What is the blood flow velocity equation?

Answer 38

Flow (F)= Pressure (P) / Resistence (R)

Question 39

T/F: higher the resistence, the higher the flow

Answer 39

false, its the opposite higher resistance= lower the flow

Question 40

What are the 4 factors determining the amount of resistance?

Answer 40

1) radius/diameter of blood vessel 2) length of blood vessel 3) viscosity of blood 4) turbulence (how is liquid moving) note: resistance also depends on blood vessel arrangement-> series or parallel

Question 41

The arteries, arterioles, capillaries, venules, and veins are collectively arranged in _______

Answer 41

series

Question 42

When blood vessels are arranged in series, flow through each blood vessel is the same, and the total resistance to blood flow is equal to the _____ of the resistance of each vessel

Answer 42

sum

Question 43

Blood vessels branch extensively to form parallel circuits that supply blood to the many organs and tissues of the body. This parallel arrangement permits each tissue to regulate....

Answer 43

its own blood flow, independently of flow to other tissues

Question 44

__________ and __________ of a blood vessel change flow and conductance

Answer 44

Radius, length

Question 45

______________ is a measure of the blood flow through a vessel for a given pressure difference

Answer 45

Conductance

Question 46

What is the exact reciprocal of resistance?

Answer 46

conductance

Question 47

What is the conductance equation?

Answer 47

conductance= 1/resistance

Question 48

What is the conductance of a blood vessel with a diameter of 1? test q

Answer 48

1 ml/min

Question 49

What is the conductance of a blood vessel with a diameter of 2?

Answer 49

16 ml/min

Question 50

What is the conductance of a blood vessel with a diameter of 4?

Answer 50

256 ml/min

Question 51

Would a small or large blood vessel have more resistance?

Answer 51

small vessel

Question 52

The greater the viscosity, the _________ the flow in a vessel if all other factors are constant

Answer 52

lower

Question 53

The viscosity of normal BLOOD is about ______x as great as the viscosity of water

Answer 53

3

Question 54

What factors could affect blood viscosity?

Answer 54

-anemia (low RBCs) -dehydration -high glucose -blood temp -inflammation -fibrinogen/coagulation levels

Question 55

The viscosity of normal PLASMA is about ______x as great as the viscosity of water

Answer 55

4 note: with anemia this would decrease

Question 56

What does PCV stand for?

Answer 56

packed cell volume

Question 57

What percentage of a normal hematocrit/PCV test is plasma? test q

Answer 57

60%

Question 58

What percentage of a normal hematocrit/PCV test is RBCs? test q

Answer 58

40% (so 40% of blood should be RBCs)

Question 59

The flow of blood in straight blood vessels like the flow of liquids in narrow rigid tubes, is normally ___________

Answer 59

laminar

Question 60

When blood flows at a steady rate through a long smooth blood vessel, it flows in streamlines each layer of blood remaining the same distance from the vessel wall. This type of flow is called _______________

Answer 60

laminar flow or streamline flow

Question 61

Where is velocity the greatest in a vessel?

Answer 61

the center

Question 62

What is another term used to describe turbulent blood flow? test q

Answer 62

chaotic or eddy currents (more turbulence= more energy needed to get from point A to B)

Question 63

When does turbulent blood flow occur?

Answer 63

-velocity of flow becomes too high above the critical velocity -scars, obstructions -branch points of large arteries -stenotic vessels (narrowing) -across heart valves or rough surfaces

Question 64

The tendency of turbulent flow increases in DIRECT proportion to....

Answer 64

-the velocity of blood flow -the diameter of the blood vessel -the density of the blood

Question 65

The tendency of turbulent flow increases in INVERSE proportion to....

Answer 65

the viscosity of the blood

Question 66

What does Reynolds' number (Re) represent?

Answer 66

measure of the tendency for turbulence to occur

Question 67

The higher the value of Re, the ____________ the probability of turbulence test q

Answer 67

greater

Question 68

As viscosity decreases, Re _____________ test q

Answer 68

increases

Question 69

As velocity increases (ex: increased CO), Re ___________ test q

Answer 69

increases

Question 70

Decrease in diameter (thrombus, plaque), velocity increases so Reynolds number ______________ test q

Answer 70

increases

Question 71

T/F: all blood vessels are distensible

Answer 71

true

Question 72

The most distensible of all vessels are....

Answer 72

veins

Question 73

What is the vascular distensibility equation?

Answer 73

vascular distensibility= increase in volume/ increase in pressure x original volume

Question 74

Veins are about ______x more distensible than the arteries

Answer 74

8

Question 75

What is the compliance/capacitance of a vascular bed equation?

Answer 75

vascular compliance = increase in volume/ increase in pressure

Question 76

Are compliance and distensibility the same thing?

Answer 76

no!!!!

Question 77

Compliance = distensibility x ____________

Answer 77

volume

Question 78

A small change in pressure would have a huge effect on the....

Answer 78

venous system