Part 2

Question 1

platelets help in the repair of a damaged vessel wall by releasing what substance

Answer 1

growth factor

Question 2

normally what prevents platelets from adhering to a normal endothelium

Answer 2

glycoproteins in the platelet wall

Question 3

what function does thromboxane A2 play in activation of platelets

Answer 3

potentates platelet granule release

Question 4

what is not a function of prostacyclin

Answer 4

acts as a vasoconstrictor

Question 5

how does aspirin block the formation of both thromboxane A2 and prostacyclin production

Answer 5

blocks FA cyclooxygenase

Question 6

which is capable of dissolving or liquifying a blood clot

Answer 6

plasmin

Question 7

how does dicumarol function as an anticoagulant

Answer 7

inhibits liver clotting factors

Question 8

what is the cause of a repercussion injury in the myocardium

Answer 8

free radical damage

Question 9

what effect will occur if fast Na channels in a cardiac cell is blocked

Answer 9

the cell will depolarize at a slower rate

Question 10

if EDV is 150 mL and ESV is 100 mL, what is the ejection fraction

Answer 10

33%

Question 11

during isovolumic contraction to the left-sided valves are in what state

Answer 11

mitral closed, aortic open

Question 12

most of the blood ejected from the ventricles is ejected in the first half of the ejection phase

Answer 12

true

Question 13

what percent of blood that moves from atria to ventricles is actively pumped by the atria

Answer 13

25%

Question 14

what is the major function of the AV node

Answer 14

delay the wave of depolarization from entering the ventricles

Question 15

the stable resting polarized state in a typical cardiac muscle cell is due to

Answer 15

K at its Nernst equilibrium and an impermeable membrane to Na and Ca

Question 16

under resting conditions, what % of oxygen is being extracted fro the arterial blood that is perfusing the myocardium

Answer 16

about 70%

Question 17

how does digitalis act to increase strength of contraction

Answer 17

decreases function of calcium exchange protein

Question 18

the first heart sound is associated with what event

Answer 18

closure of the AV valves

Question 19

a machinery murmur heard throughout the entire cardiac cycle is likely associated with what condition

Answer 19

patent ductus arteriosis

Question 20

a machinery murmur heard throughout the entire cardiac cycle is likely associated with what condition

Answer 20

patent ductus arteriosis

Question 21

a diastolic murmur would likely be associated with what condition

Answer 21

aortic insufficiency

Question 22

as systemic arterial blood pressure is increased, what happens to the strength of left ventricular contraction if the ANS effect on the heart is blocked

Answer 22

decrease in LV contractile strength

Question 23

what is the function of the papillary muscles in the wall of the RVs when they contract

Answer 23

prevents prolapse of the tricuspid valve

Question 24

which are dependent on ANS function

Answer 24

pressure induced homeometric autoregulation

Question 25

how does the stretch on the SA nose increase HR

Answer 25

by increasing membrane permeability to Na/Ca

Question 26

increase EC K levels 2-3X above normal will have what effect on myocardial performance

Answer 26

extreme weakness and flaccidity

Question 27

what effect would a fever of 100 degrees F have on resting HR

Answer 27

increased HR 10 bpm

Question 28

most of the energy consumed by the heart is associated with

Answer 28

the production of heat

Question 29

the principal energy source for cardiac output is

Answer 29

FAs

Question 30

increased stretch on the ventricular myocardium at the end of diastole is associated with

Answer 30

increase calcium influx

Question 31

PSNS activation can cause inhibition of NE release presynaptically

Answer 31

true

Question 32

what is most responsible for the all or none response of the cardiac myocardium

Answer 32

intercalated discs

Question 33

what is not a feature of the SA node

Answer 33

stable resting polarized state

Question 34

in a third degree AV block, what is true

Answer 34

the atria and ventricles are beating independently

Question 35

describe atrial repolarization

Answer 35

buried in the QRS complex

Question 36

what normally prevents cells other than SA nodal cells from firing spontaneously

Answer 36

purkinje cells

Question 37

if the net deflection of the QRS complex in lead I is negative 5 mm, and the net deflection in lead AvF is positive 5 mm, what can you say about the mean electrical axis

Answer 37

right axis deviation