Chest Pain quiz

Question 1

What is the equation for cardiac output

Answer 1

CO = HRxSV

Question 2

Which side of the heart provides systemic circulation?

Answer 2

Left side

Question 3

Which side of the heart provides pulmonary circulation?

Answer 3

Right side

Question 4

What kind of circuit is between the pulmonary and systemic?

Answer 4

Series

Question 5

What kind of circuit is between all the organs in systemic?

Answer 5

Parallel

Question 6

What is the equation for Ohm’s law in hemodynamics?

Answer 6

Q = delta P / R

Question 7

What is pressure difference in hemodynamics?

Answer 7

Delta P = MAP - CVP

Question 8

What is normal BP (systole/diastole)?

Answer 8

130/80

Question 9

What are the three main functions of cardiac action potentials?

Answer 9

Pacemaking by SA node, conduction of the impulse, initiating and controlling contraction

Question 10

What demonstrates fast APs?

Answer 10

Atrial muscle, ventricular muscle, his/purkinje (LEFT SIDE)

Question 11

What demonstrates slow APs?

Answer 11

Pacemaking (SA node), and slow conduction AV node (RIGHT SIDE)

Question 12

What are the phases of a fast AP (0-4)?

Answer 12

0: Rapid depolarization activation of inward Na+
1: Initial repolarization (inactivate inward Na+, activate outward K+)
2: Plateau phase mediated by slowly activating inward Ca++
3: Repolarization due to inactivation of Ca currents and activation of several K+ currents
4: Resting membrane pot’l due to inward-rectivying K+ channels

Question 13

What are the phases of a slow AP (0-4)?

Answer 13

0: slow depolarization due to activation of slowly-activating Ca++ channels
1: absent
2: absent
3: repolarization due to Ca++ channel inactivation and activation of K+ channels
4: slowly depolarizing resting potential

Question 14

What effect does the parasympathetic NS have on phase 4 depolarization?

Answer 14

The parasympathetic NS releases ACh which reacts with muscarinic ACh recepters, increase in Igirk K currents, reducing the depolarization and HR (negative chronotropic effect)

Question 15

What effect does the sympathetic NS have on phase 4 depolarization?

Answer 15

Sympathetic NS releases NorEpi and Epi at the heart which interact with B1 adrenergic recepts, increases both If (slow Na channels) and Ica leading to increase in HR and positive chronotropic effect

Question 16

What is the P-wave?

Answer 16

It is the wave of depolarization from the SA node through the atria

Question 17

What is the PR segment of an EKG?

Answer 17

It is the section after the P wave where there is no detectible signal as it is depolarizing the AV node

Question 18

What is the Q-wave?

Answer 18

The depolarization wave along the bundle of his and purkinje fibers

Question 19

What is the R-wave?

Answer 19

The peak, due to the mass of muscle involved. Wave of depolarization spreads throughout the ventricle, the deflection returns to zero.

Question 20

What is the S-wave?

Answer 20

The last part of the ventricle to depolarize is near the atrium, a brief negative deflection occurs

Question 21

What is the T-wave?

Answer 21

The ventricle repolarizes

Question 22

How do you measure heart rate?

Answer 22

The sinus rhythm is the interval between successive P-waves

Question 23

Where are the different leads located? (aVr, aVL, aVf, I, II, III)

Answer 23

aVr: -150, aVL = -30, I = 0, II = +60, aVf = +90, III = 120

Question 24

What is indicative of a heart block/AV nodal depression?

Answer 24

The PR-interval will increase, or the PR interval will not be followed by a QRS wave

Question 25

What causes an abnormal QRS complex?

Answer 25

Premature ventricular complex

Question 26

What is indicative of subendocardial injury?

Answer 26

ST depression

Question 27

What is indicative of a transmural epicardial injury?

Answer 27

ST elevation

Question 28

What is the equation for stroke volume?

Answer 28

EDV-ESV = SV (NORMAL = 60-100)

Question 29

What is the equation for ejection fraction/

Answer 29

EJ = SV/EDV (NORMAL = 55-70%)

Question 30

What is preload?

Answer 30

Preload s the load present before contraction has started, is provided by the venous return that fills the atrium and enters the ventricle during diastole. Preload represents ventricular stretching prior to contraction

Question 31

What is the law of LaPlace

Answer 31

Wall stress = (Pressure x chamber radius)/(2 wall thickness)

Question 32

What is afterload?

Answer 32

Afterload represents the force that the heart has to overcome to force blood into the aorta, technically, afterload is the wall stress present at peak systolic pressure

Question 33

What is inotrophy?

Answer 33

The ability to modulate the degree of force generation in cardiac muscle

Question 34

What effect does increasing preload have on SV and CO?

Answer 34

Increasing preload increases stroke volume to increase CO

Question 35

What is one pathophysiological example of increasing preload?

Answer 35

In the case of heart failure. The reduced CO triggers compensatory steps to increase blood vol thereby increasing preload and CO. (Can lead to hypertrophy by LaPlace law)

Question 36

What is one pathophysiological example of increasing afterload?

Answer 36

Aortic stenosis. Left ventricular emptying is impared due to narrowing of aortic valve leading to higher resistance, leading to compensatory increase in EDV limited by ventricular hypertrophy leading to a large increase with EDP

Question 37

What is one physiological example of increasing inotrophy?

Answer 37

Increase the amount of Ca that enter the cardiac myocyte during phase 2 of the AP leading to an increase in the amount of Ca released from the SR generating a larger force of contraction. This can be seen through symphathetic NS.

Question 38

What is Poiseulle's equation?

Answer 38

Q=(deltaP*pie*r^4)/(8*L*viscosity) - not the prettiest I know I apologize

Question 39

What is the relationship between flow and radius?

Answer 39

If increasing radius by 2, you are increasing flow by 16

Question 40

What is normal viscosity and the factors effecting viscosity?

Answer 40

Normal - 38-54%, factors: altitude, polycythemia vera, severe dehydration, sickle-cell anemia

Question 41

What is resistance in series and in parallel?

Answer 41

Series = Rtot=R1+R2+R3, Parallel 1/RTOT=1/R1 + 1/R2 +1/R3

Question 42

What is the equation for total peripheral resistance?

Answer 42

TPR = (MAP - CVP)/CO

Question 43

How can MAP be calculated?

Answer 43

``` MAP = DBP + (PP)/3 PP = SBP-DBP ```

Question 44

What is Starling's law of the Capillary?

Answer 44

Bulk flow Q= K(Hydro Cap + tissue oncotic) - (Hydro tissue + Plasma oncotic)

Question 45

What are the two types of control of blood flow through the capillaries?

Answer 45

Local control and central control (CNS)

Question 46

What are the two main mechanisms of local control?

Answer 46

Metabolic - increase metabolic waste -> vasodilation -> increase blood flow Myogenic - increased pressure, muscle contracts, resistance increases (autoregulation of blood flow)

Question 47

What are the two main mechanisms of central control?

Answer 47

Humoral mechanisms-everywhere and Neural mechanisms-fine control

Question 48

What does ANP cause?

Answer 48

Atrial natriuretic peptide - causes excretion of Na and water, also causes vasodilation to decrease TPR

Question 49

What does AngII cause?

Answer 49

Angiotensin II is a potent vasoconstrictor; stimulating aldosterone synthesis and release for retention of Na

Question 50

What does Epidnephrine cause?

Answer 50

released from adrenals via sympathetic stimulation vasodilation in live and skeletal muscle; increases heart rate

Question 51

What does NO cause

Answer 51

Gas produced by endotheliu, very short half life cause vascular relaxation and vasodilation

Question 52

What does Endothelin do?

Answer 52

ET-1 is a potent vasoconstrictor from endothelium