Exam 3- CV dynamics

Question 1

Flow rate of a liquid through a pipe is

Answer 1

directly proportional to the pressure gradient

indirectly proportional to the pipe’s resistance

Question 2

select the three best choices that would DECREASE RESISTANCE to blood flow

Answer 2

increase radius

decrease length and blood viscosity

Question 3

which has the greatest effect on blood flow

Answer 3

radius

Question 4

blood flows in the opening of the blood vessel referred to as the _____

Answer 4

lumen

Question 5

the driving force for blood flow is

Answer 5

pressure gradient

Question 6

the body increases blood vessel radius through

Answer 6

smooth muscle rlaxation

Question 7

after eating a heavy meal, while inactive one would expect

Answer 7

blood vessels to skeletal muscles to be constricted

blood vessels to digestive organs to be dilated

Question 8

what is the source of the pressure gradient that drives fluid/blood flow in the body?

Answer 8

CO/ the heart pump

Question 9

when you increased the flow tube radius the fluid flow rate

Answer 9

increased exponentially by a factor of 4

Question 10

which do NOT contribute to viscosity of blood

Answer 10

CO2, O2, Na+ [ ]

Question 11

the thickness or “stickiness” of a fluid is the ____

Answer 11

viscosity

Question 12

increasing the viscosity

Answer 12

decreases flow rate

Question 13

hypoalbuminemia is a reduction in serum albumin. The effect on blood viscosity would be to

Answer 13

decrease blood viscosity thus decrease resistance

Question 14

with dehydration one would predict

Answer 14

increased viscosity and decreased flow rate

Question 15

describe the components of blood that affect viscosity, and how changing the components change viscosity

Answer 15

The components of blood that affect viscosity are plasma proteins and formed elements. These include WBCs, RBCs, and platelets. Increasing any of these components will cause them to slide past one another more, increasing resistance and viscosity (decreasing flow rate). Decreasing any of these components will cause them to slide past eachother less, decreasing viscosity (increasing flow rate).

Question 16

decrease blood flow

Answer 16

polycythemia vera
IV transfusion of RBCs
dehydration

Question 17

increases blood flow

Answer 17

iron deficient anemia
liver disease
chronic gloeruloephritis
IV hydration with normal saline

Question 18

What happens to vessel length then you lose weight?

Answer 18

decreases

Question 19

increased flow tube length this lead to a

Answer 19

decreased flow rate

Question 20

Which change occurs on a daily basis

Answer 20

diameter

Question 21

The body might decrease vessel radius

Answer 21

decrease delivery of nutrients to an area that is less metabolically active

Question 22

which correctly describes the relationship between blood vessel length, resistance and blood flow

Answer 22

blood vessel length is directly proportional to resistance and inversely proportional to blood flow

Question 23

why does a 10% change in blood vessel radius affect blood flow more than a 10% change in blood vessel length?

Answer 23

When changing blood vessel radius by 10%, blood flow is affected by more than 10% because blood flow increases to the fourth power of the vessel radius.

Question 24

why does weight change affect blood pressure

Answer 24

Weight directly affects the length of the vessels. The longer the vessel (heavier person) the more resistance/friction in the vessel, slowing th flow and increasing the pressure. The opposite will happen for a lighter person. Shorter vessel, less resistance, faster flow, decreased pressure

Question 25

the driving force for blood flow is

Answer 25

pressure gradient, which increases with an increase in cardiac output

Question 26

increased pressure or cardiac output from the heart will, in absence of other changes

Answer 26

increased blood flow

Question 27

arteries closest to the heart are described as elastic arteries because they stretch in response to

Answer 27

pressure from ejection of blood during systole

Question 28

What is laminar flow, and what effect does a smaller vessel radius have on laminar flow

Answer 28

Laminar flow is blood that flows freely in the middle of the vessel. In a smaller, vasoconstricted vessel there is more contact between the blood and the lumen decreasing laminar flow. This prevents or delays the rate of blood flow in the vasoconstricted vessel when compared to vasodilated vessels.

Question 29

isolated increase in force of contraction in the heart would likely

Answer 29

increase BP

Question 30

isolated increase in arterial radius would likely

Answer 30

increase BF to the area

Question 31

Was the plot for change in pressure different than that for changes in radius/viscosity or tube length? If so what was different

Answer 31

he pressure plot had a linear trend in the positive direction demonstrating a directly proportional relationship. The radius/viscosity and tube length, the trend was in an exponential manner representing the indirect relationship

Question 32

There is a more effective method for controlling blood flow throughout the body than changing the strength of contraction of the heart. What is it and why is it more effective?

Answer 32

The more effective method of controlling blood flow would be vasoconstriction and vasodilation. Changing the vessel diameter controls the flow of blood more effectively because it is a factor that is more easily changed from minute to minute.

Question 33

hen the piston pushed blood out of the chamber the volume remaining in the chamber would be closest to the

Answer 33

ESV

Question 34

layer of a blood vessel most affected by the ANS is

Answer 34

smooth muscle

Question 35

ncreased contractility of the heart results in all but which of the following

Answer 35

increase ESV

Question 36

the effect of increasing the R flow tube radius

Answer 36

increased flow rate decreased resistance increased pump rate

Question 37

In a normal individual [a] percent of the blood contained within the heart is ejected during ventricular systole leaving [b] percent in the ventricle

Answer 37

60, 40

Question 38

at rest the overlap length for maximum tension production in cardiac muscle is

Answer 38

less than optimum

Question 39

factors that can decrease preload are

Answer 39

severe blood loss tachycardia dehydration

Question 40

The cardiovascular system can adjust blood flow from either the heart or the peripheral vascular system. What two changes can the heart make to adjust blood flow? would this have a systemic effect (affect the whole body) or a local effect (just affect one part of the body)

Answer 40

change SV and HR | effect on systemic- BP and blood flow

Question 41

the degree to which the ventricles are stretched by the end diastolic volume is the _____

Answer 41

preload

Question 42

the pump rate was analogous to the heart rate, what happened to the rate when you increased the stroke volume?

Answer 42

the pump rate decreased to maintain cardiac output

Question 43

why might an athlete's resting Heart rate be lower than an untrained individual

Answer 43

the athlete's heart has stronger contractions thus stronger stroke volume

Question 44

compare optimal muscle length in cardiac muscle compared to that in skeletal muscle. What does this mean for cardiac function?

Answer 44

Optimal length for cardiac muscles is in a stretched length compared to skeletal muscle which has an optimal length at rest. The stretching of the myocardium allows for the sarcomeres to have optimal overlap of actin and myosin to produce the most efficient contraction. For cardiac function, this means that the more preload (prestretch) of the cardiac muscle, the stronger the contraction

Question 45

Which had the greatest compensatory effect?

Answer 45

increasing pump pressure

Question 46

Aortic valve stenosis would cause an

Answer 46

increased L ventricular afterload

Question 47

in vivo the heart would compensate for a decrease in flow tube radius by

Answer 47

adjusting the force of contraction of the heart

Question 48

In arteriosclerosis arteries lose their elasticity. One would expect

Answer 48

an increase in systolic BP, a decrease in diastolic BP thus a widening of the pulse pressure

Question 49

in aortic valve regurgitation during diastole blood flows back into the L ventricle. This effect would

Answer 49

increase preload in the next cycle thus increasing pulse pressure