Cardiovascular Physiology

Question 0

What is ANP (atrial natriuretic peptide) released in response to?

Answer 0

Increased atrial pressure

Question 1

How many liters of blood per minute is pumped in a 70kg man

Answer 1

5-6 liters

Question 2

What is BNP (b-type natriuretic peptide) released in response to?

Answer 2

overstretched ventricles

Question 3

Intercalated discs allow the heart to contract in synchrony as one unit, what is this called?

Answer 3

Syncytium

Question 4

What is happening with the ions in the initial repolarization in cardiac muscle contraction?

Answer 4

Inactivation of Na+ influx

K+ efflux

Question 5

What is happening in the plateau phase of the cardiac muscle contraction? (ions)

Answer 5

Ca++ influx through L-type Ca++ channels

Question 6

What determines the force of contraction of the myocardial cell?

Answer 6

The amount of intracellular calcium

Question 7

No action potential can be initiated regardless of the stimulus strength, what refractory period is this?

Answer 7

Absolute refractory period

Question 8

An action potential can be elicited, however a greater stimulus is needed, what refractory period is this?

Answer 8

Relative refractory period

Question 9

Why is cardiac muscle incapable of sustained contraction (tetany) as in skeletal muscle?

Answer 9

Because of the relatively long refractory period

Question 10

What is the Frank-Sterling law?

Answer 10

Cardiac output is directly proportional to venous return

Question 11

The 1st heart sound is due to what?

Answer 11

Closure of the tricuspid and mitral valves

Question 12

The 2nd heart sound is due to what?

Answer 12

Closure of the pulmonary and aortic valves

Question 13

3rd heart sound occurs when?

Answer 13

After the 2nd heart sound and is seen in congestive heart failure

Question 14

The 4th heart sound is heard when?

Answer 14

Before the 1st heart sound and is seen in hypertrophic ventricles

Question 15

Systole (contraction) occurs between which heart sounds?

Answer 15

1st and 2nd

Question 16

Diastole (relaxation) occurs between which heart sounds?

Answer 16

2nd and 1st

Question 17

If there is a prolonged PR interval (>200 milliseconds)

Answer 17

1st degree AV block

Question 18

If there is progressive prolongation of the PR interval with dropped beats

Answer 18

2nd degree AV block (Mobitz 1- Wenckebach phenomenon)

Question 19

Isovolumic contraction occurs when?

Answer 19

Between the closure of the AV valves and the opening of the aortic valve

Question 20

Increase in pressure without change in volume is called what?

Answer 20

Isovolumic contraction

Question 21

What is it called when only 70ml of the 120ml of blood is expelled from the ventricle?

Answer 21

Ejection fraction

Question 22

A decrease in the ventricular pressure without a change in the volume is called?

Answer 22

Isovolumic relaxation

Question 23

When does isovolumic relaxation occur?

Answer 23

Between the closing of the aortic valve and the opening of the AV valves

Question 24

Sympathetic control of heart rate comes from which vertebral levels and which sympathetic ganglia?

Answer 24

T1-T5, middle and inferior cervical ganglia

Question 25

What is it called when the sympathetic nervous system increases heart rate?

Answer 25

Positive chronotropism

Question 26

How does the sympathetic nervous system increase the heart rate?

Answer 26

By increasing the rate of Phase 4

Question 27

What is it called when there is an increase in conduction velocity?

Answer 27

Positive dromotropism

Question 28

How does the sympathetic nervous system increase conduction velocity?

Answer 28

By decreasing the PR interval

Question 29

What is it called when there is an increase in force of contraction in the heart?

Answer 29

Positive inotropism

Question 30

How does the sympathetic nervous system increase force of contraction?

Answer 30

By increasing Ca++ influx in Phase 2

Question 31

Which CN controls parasympathetic control to the heart?

Answer 31

Vagus through its cardiac branches

Question 32

Cardiac Output x Peripheral Resistance = ?

Answer 32

Blood Pressure

Question 33

Stroke Volume x Heat Rate = ?

Answer 33

Cardiac Ouput

Question 34

Afferent high pressure sensors (baroreceptors) information in the carotid sinus are carried in which nerve?

Answer 34

Cranial nerve IX

Question 35

Afferent high pressure sensors (baroreceptors) information in the aortic arch is carried in which nerve?

Answer 35

Cranial nerve X

Question 36

CN IX and CN X carry afferent high pressure baroreceptor information to which area of the brain?

Answer 36

The Medulla

Question 37

Where are the low pressure baroreceptors located?

Answer 37

SVC, IVC and the right atrium

Question 38

What do low pressure baroreceptors monitor?

Answer 38

Volume

Question 39

What is Poiseuille's Law?

Answer 39

Peripheral resistance is directly proportional to viscosity of blood and lenth of the vessel and inversely proportional to the radius of the vessel raised to the 4th power

Question 40

The greatest resistance in the vascular system is offered where?

Answer 40

Arterioles

Question 41

Blood flow through a tubular structure is governed by which law?

Answer 41

La Place's law

Question 42

What is La Place's law?

Answer 42

The pressure within a blood vessel is related to the tension, size and shape of the vessel

Question 43

What is blood flow inversely proportional to?

Answer 43

The diameter of the blood vessel

Question 44

How much of the total blood volume is contained within the venous system?

Answer 44

60%

Question 45

How much of the total blood volume is contained within the pulmonary system?

Answer 45

15%

Question 46

How much of the total blood volume is contained within the capillaries?

Answer 46

5%

Question 48

Where is blood flow the greatest?

Answer 48

Within the arteries and veins

Question 49

Where is the least amount of blood flow?

Answer 49

The capillaries

Question 51

How much of the total blood volume is contained within the arteries and arterioles?

Answer 51

20%

Question 52

Pressure which tends to force fluids out into the interstitial space (+)

Answer 52

Intracapillary hydrostatic

Question 53

Pressure which tends to pull fluids into the capillary (-)

Answer 53

Intracapillary oncotic pressure

Question 54

Pressure which forces fluids into the capillary

Answer 54

Interstitial hydrostatic pressure

Question 55

Pressure which pulls fluid out of the capillary

Answer 55

Interstitial oncotic pressure

Question 56

Prolonged exercise leads to cardiac muscle hypertrophy which leads to?

Answer 56

Athletic Heart Syndrome