CV system

Question 1

t/f: the main drop in pressure occurs in the arteries

Answer 1

false. it occurs in the arterioles

Question 2

t/f: contributing factors to BP are ANS, cardiac output, and peripheral vascular resistance

Answer 2

true

Question 3

cardiac output

Answer 3

volume of blood pumped by the heart in 1 minute (5 L/min)

Question 4

t/f: altering heart rate will alter chronotropy

Answer 4

true

Question 5

t/f: altering stroke volume will alter inotropy

Answer 5

true

Question 6

altering chronotropy and inotropy will alter cardiac output

Answer 6

true

Question 7

preload

Answer 7

initial stretching of myocardium before contraction

Question 8

afterload

Answer 8

force of heart during contraction

Question 9

frank-starling mechanism

Answer 9

increasing the stretch increases the contractility

Question 10

laplace’s law

Answer 10

increase stretch will increase the tension

Question 11

normal ejection fraction is

Answer 11

55-75%

Question 12

formula for ejection fraction

Answer 12

sv/edvv

Question 13

t/f: nitric oxide and prostacyclin cause vasoconstriction

Answer 13

false. they cause vasodilaton

Question 14

t/f: thrombozane and endothelins cause vasodilation

Answer 14

false. they cause vasoconstriction

Question 15

t/f: nitric oxide is formed by an enzyme (NOS) that is activated by Ca ions

Answer 15

true

Question 16

nitric oxide mechanism

Answer 16

• nitric oxide diffuse between endothelial cells
• activate guanylyl cyclase
• increase cGMP
• activate protein kinase G (by phosphorylation)
• vasodilation

Question 17

t/f: the RAAS system modulates vasoconstriction, causing increase BP and hypertension

Answer 17

true

Question 18

t/f: treatments for hypertension can target the RAAS system

Answer 18

true

Question 19

t/f: resting membrane potential of ventricles is around -85 to -90 mV

Answer 19

true

Question 20

t/f: the main ions involved in action potentials are sodium, potassium, and calcium

Answer 20

true

Question 21

t/f: during contraction, L-type sodium channels open

Answer 21

false. L-type calcium

Question 22

t/f: digitalis is a cardiac glycoside that reversibly inhibits the na-k atpase pump

Answer 22

true

Question 23

t/f: digitalis will cause decreased contractility

Answer 23

false. it will increase contractions (by increasing ca ions in the myocyte)

Question 24

t/f: the SA node has a higher resting membrane potential

Answer 24

true (so easier to stimulate)

Question 25

t/f: it is easier to stimulate the SA node due to its lower peak and less steep slope

Answer 25

true

Question 26

at/f: ventricular action potential begins with a fast outward of sodium ions

Answer 26

false. fast inward of sodium

Question 27

t/f: SA node action potential begins with a fast inward of sodium

Answer 27

false. sustained (slower) inward of calcium

Question 28

t/f: electrocardiogram is an electrical recordign of all changes/action potentials across the heart

Answer 28

true

Question 29

P wave represents

Answer 29

atrial depolarization

Question 30

QRS complex represents

Answer 30

ventricular depolarization

Question 31

T wave represents

Answer 31

ventricular repolarization

Question 32

PR interval represents

Answer 32

AV conduction (time between signal from atria to ventricle)

Question 33

t/f: ST segment can be changed by ischemia

Answer 33

true

Question 34

t/f: depression of the ST segment is caused by transmural ischemia

Answer 34

false. it’s caused by subendocardial ischemia

Question 35

t/f: elevation of ST segment is caused by subendocardial ischemia

Answer 35

false. it’s caused by transmural ischemia

Question 36

t/f: the function/activity of the heart can be viewed using MRI

Answer 36

false. it is seen in SPECT