Deck 14: The Cardiovascular System: the Heart

Question 1

Is the pulmonary circulation parallel or in series to the systemic circulation?

A) parallel
B) in series
C) both
D) they are independent

Answer 1

B

Question 2

Heart valves ensure that blood will flow one-way. Which of the following accurately describes the role differences in pressure play in valve function?

A) AV open when pressure in the ventricles exceeds pressure in the atria.
B) SL open when pressure in the ventricles exceeds pressure in the arteries.
C) AV open when pressure in the ventricles exceeds pressure in the arteries.
D) SL open when pressure in the ventricles exceeds pressure in the atria.

Answer 2

B

Question 3

One of the functional tests of lung's oxygenating capacity requires comparing blood oxygen levels in most and least oxygenated points of the cardiovascular system. Where are these points respectively?

A) aorta and pulmonary vein
B) aorta and pulmonary artery
C) systemic veins and pulmonary artery
D) pulmonary veins and left ventricle

Answer 3

B

Question 4

When electricians assemble electrical circuits, they do it either parallel or in-series depending on the application. Isn't it amazing that evolution came up with the same idea way before the electricians did? Thinking about blood distribution throughout the body, which circuit is more widely represented in human body?

A) parallel
B) in series
C) both about even
D) There is no similarity between blood flow and electrical current flow.

Question 5

Identify the part of the heart that is incorrectly matched with its associated function.

A) coronary arteries: supply oxygen and nutrients to the heart muscle cells
B) purkinje fibers: initiate the changes of electrical potential in the heart.
C) ventricular septum: prevents mixing of oxygenated and deoxygenated blood
D) AV valves: force one-directional blood flow

Question 6

In pericarditis, excessive fluid accumulates in the pericardial cavity impairing heart's pumping ability. An immediate intervention to prevent heart tamponade is inserting a needle and draining the fluid. What layers of membranes would a cardiologist have to puncture to get there?

A) myocardium
B) endocardium
C) parietal layer of pericardium
D) visceral layer of pericardium

Question 7

Blood flow through the systemic circulation is "parallel". What is the physiological importance of such an arrangement?

A) it makes blood flow faster increasing the speed of delivery of essential nutrients and gases
B) it prevents organs from receiving used up blood that has passed through another organ already
C) it allows for central unified control of blood flow and blood pressure
D) it prevents back up of blood in systemic circulation in case of heart failure

Question 8

Which of the following chambers of the heart is surrounded by the thickest layer of myocardium?

A) right atrium
B) right ventricle
C) left atrium
D) left ventricle

Question 9

Parallel mode of blood flow means that

A) all blood vessels run parallel to one another
B) arteries run from one organ to another delivering blood in specified order
C) each organ receives equally oxygenated blood from its own arterial branch
D) arteries and veins are always parallel to each other

Question 10

During atrial fibrillation the electrical activity of atria is desynchronized and the atria do not contract. That causes the formation of blood clots in the atria. If a clot from the atria detaches and gets into circulation it might cause the blockage of blood flow to a certain area. Where would you find a blood clot that originated in the right atrium?

A) in the arteries in the lungs
B) in the coronary circulation
C) in one of the arteries in the legs
D) in the left ventricle

Question 11

The left ventricle works harder than the right ventricle because

A) the left ventricle pumps blood a longer distance than the right
B) there is a lower resistance to blood flow in the left ventricle
C) the left ventricle pumps larger volume of blood
D) All of the choices are correct.

Question 12

When inserting pacemaker leads into the left ventricle of the heart where would you insert a catheter?

A) in a systemic artery
B) in a systemic vein
C) in a pulmonary artery
D) it does not matter, the CV system is a closed circuit so I will get there eventually

Question 13

All of the following are the advantages of parallel blood flow in systemic circulation EXCEPT?

A) it allows each organ to receive equally oxygenated blood
B) it allows for independent regulation of blood flow to each organ
C) it makes sure other organs will keep receiving blood when one of them fails
D) it makes sure all organs receive the same volume of blood

Question 14

The apex of the heart is normally pointed

A) exactly at the midline
B) to the left of the midline
C) to the right of the midline
D) it is different for males vs females

Question 15

What organ's blood circulation is the exception to the rule of parallel flow, and one capillary bed between artery and vein?

A) brain
B) kidney
C) heart
D) striated muscle

Question 16

The tricuspid valve's job is to ensure that blood flows in one direction. If there is a defect of the tricuspid valve, where is backflow expected to happen?

A) backflow of blood from aorta into the left ventricle
B) backflow of blood from left ventricle into the right atrium
C) backflow of blood from right ventricle to right atrium
D) backflow of blood from left ventricle to left atrium

Question 17

The left ventricle has the thickest wall of the 4 chambers of the heart. What is the physiological explanation for that?

A) the left ventricle is the strongest pumping chamber of the heart
B) the left ventricle transfers blood from the systemic circulation to be oxygenated
C) the left ventricle uses only anaerobic glycolysis as energy source
D) the left ventricle does not have any valves

Question 18

During the heart dissection lab, you are supposed to cut the wall of right ventricle first. But you get a little disoriented how to properly position a heart on your table. Nevertheless you make the cut and open the heart. Of the following, which is the best way to recognize that you are in the correct ventricle?

A) The walls of the ventricle I opened are thick.
B) There are four holes leading to this chamber with no valves.
C) The valve inside the chamber I opened has three flaps.
D) There is no valve where the large blood vessels attach.

Question 19

Where in the circulatory system would you find blood with lowest oxygen saturation levels?

A) pulmonary vein
B) pulmonary artery
C) aorta
D) coronary arteries

Question 20

Blood returning to the heart from the systemic circulation first enters the

A) right atrium
B) left atrium
C) right ventricle
D) left ventricle

Question 21

Main ions that contribute to excitation-contraction coupling in the heart are

A) Ca²⁺
B) Cl ^-
C) K⁺
D) Mg²⁺

Question 22

If the SA node is damaged and stops functioning, what will most likely occur?

A) heart rate will increase
B) heart rate will decrease
C) nobody will notice, heart rate won't change
D) the heart will stop without a functioning SA node

Question 23

A part of the heart's electrical conduction system found within the ventricular myocardium is called

A) atrioventricular node
B) atrioventricular bundle
C) bundle of His
D) Purkinje fibers

Question 24

Excitation-contraction coupling in the heart can be described as

A) a cyclical change in heart function leading to production of action potentials that can be recorded as ECG
B) a sequence of processes that link the electrical changes in the heart to its contraction
C) the changes in heart metabolism in response to contraction
D) production of special type of depolarizations that only happen in the autorhythmic fibers

Question 25

The normal physiological pacemaker of the heart is

A) SA node
B) AV node
C) bundle of His
D) AV bundle

Question 26

Which of the valves listed below is NOT supported by muscular structures?

A) aortic valve
B) mitral valve
C) tricuspid valve
D) atrioventricular valve

Question 27

Which is one of the functional characteristics of cardiac myocytes that makes them adapted for the hard and continuous work they do?

A) each cardiac myocyte maintains electrical independence
B) mechanical integrity of the muscle is maintained by intercalated discs
C) excitation spreads ONLY through the specialized conduction system
D) they rely only on Ca²⁺ channels for creation of action potentials

Question 28

The largest flow through the coronary arteries can be observed

A) during ventricular systole
B) during isovolumetric ventricular contraction
C) during ventricular ejection phase
D) during ventricular relaxation

Question 29

Autorhythmic activity of the heart is the result of

A) innervation of the heart by vagus nerve
B) spontaneous generation of action potentials in the conduction system
C) response to nerve stimulation of sympathetic nerves innervating the heart
D) the interaction of somatic and autonomic nervous systems

Question 30

What is the correct order the pathway that the excitation moves throughout the heart?

A) SA node - Purkinje fibers - AV node - bundle of His
B) bundle of His - AV node - Purkinje fibers - SA node
C) SA node - bundle of His- AV node - Purkinje fibers
D) SA node - AV node - bundle of His - Purkinje fibers

Question 31

Which channel is responsible for depolarization phase of action potential in the contractile cardiac muscle fibers?

A) opening of voltage gated Na⁺ channels
B) closing of voltage gated Na⁺ channels
C) opening of fast voltage gated K⁺ channels
D) closing of slow voltage gated K⁺ channels

Question 32

Cardiac muscle fibers differ from skeletal muscle fibers in that cardiac fibers are

A) longer and greater in diameter
B) electrically coupled to one another
C) multinucleated
D) lacking cell junctions called desmosomes

Question 33

Action potential in the contractile cardiac muscle fibers has a unique shape with a long plateau. What ion channels are responsible for the plateau phase of cardiac action potential?

A) L type voltage gated Ca²⁺ channels
B) T type voltage gated Ca²⁺ channels
C) fast voltage gated K⁺ channels
D) F type Na⁺ channels

Question 34

Purkinje fibers in the heart are the modified muscle fibers that

A) form the high resistance path through the heart
B) are a primary pacemaker for the healthy heart
C) are able to generate spontaneous depolarizations
D) have unusually large number of contractile filaments

Question 35

Which cardiac valve prevents reflux of blood back into the right ventricle?

A) aortic valve
B) pulmonary valve
C) bicuspid valve
D) tricuspid valve

Question 36

What is the function of the fibrous skeleton of the heart?

A) it helps valves to open and stay open during systole
B) it electrically isolates atria and ventricles
C) it strengthens the tension of the cardiac muscle
D) it makes sure the coronary blood vessels never collapse

Question 37

What event is responsible for the excitation-contraction coupling in the myocardium?

A) increase of Ca²⁺ concentration in the sarcoplasm
B) removal of Ca²⁺ from the troponin
C) transport of Ca²⁺ to sarcoplasm by the ATPase
D) inactivation of Ca²⁺ release channels in the SR

Question 38

What ion channels in the contractile cardiac muscle fiber are open and conducting during the initial repolarizing phase of an action potential?

A) fast voltage-gated Na⁺ channels
B) fast voltage-gated K⁺ channels
C) L-type voltage-gated Ca²⁺ channels
D) slow voltage-gated K⁺ channels

Question 39

The second phase of the contractile fiber's cardiomyocyte action potential is called

A) slow depolarization
B) initial repolarization
C) final rapid repolarization
D) slow repolarization

Question 40

Which autorhythmic fibers start the impulse that is responsible for a P wave in the ECG?

A) SA node
B) AV node
C) AV bundle
D) Purkinje fibers

Question 41

Electrocardiogram is a powerful technique that allows health professionals to look at the heart's

A) pumping force
B) pressure changes during cardiac cycle
C) depolarization and repolarization cycles
D) dynamics of blood flow

Question 42

Which disorders of the heart can be seen on an ECG?

A) valve defects
B) hypoxia of the cardiac muscle
C) hypertension
D) low cardiac output

Question 43

Calculate the ejection fraction for a person with 135 mL EDV, and 65 mL of ESV.

A) 65 mL
B) 70 mL
C) 48%
D) 52%

Question 44

During passive ventricular filling phase, which are the correct states of the heart valves?

A) atrioventricular valves are closed, semilunar valves are open
B) atrioventricular valves are open, semilunar valves are closed
C) all four valves are closed
D) all four valves are open

Question 45

ECG provides information about

A) end diastolic volume of the heart
B) stroke volume
C) both end diastolic volume of the heart and stroke volume
D) electrical potentials of the heart

Question 46

The ST segment in the ECG corresponds to which mechanical events of the cardiac cycle?

A) a pause between ventricular systole and atrial diastole
B) ventricular systole
C) ventricular relaxation
D) ventricular diastole
E) nothing in particular, it's a flat line

Question 47

What is the average volume of blood in the ventricles at the end of passive ventricular filling?

A) 60mL
B) 100mL
C) 130 mL
D) 5L

Question 48

After heart attack, scar tissue develops in the heart causing a detour of action potentials traveling in the conduction system. In which part of an ECG trace would change be detected?

A) QRS complex because it is the depolarization phase of the majority of the heart muscle
B) PQ interval because it corresponds to travel of the potential in the fibers of the conduction system
C) P wave because the excitation cannot travel backward to atria
D) T wave because scar tissue can't re polarize properly

Question 49

What is an EDV?

A) the volume of blood in the ventricles at the end of passive ventricular filling phase
B) the volume of blood in the atria before they contract
C) the volume of blood in the ventricles after atria contract
D) the volume of blood in the ventricles at the end of isovolumetric relaxation

Question 50

The cardiac cycle proceeds in a series of 5 phases. Identify the phases of cardiac cycle for the state atrial diastole, ventricular systole. Select all that apply.

A) passive ventricular filling
B) atrial contraction
C) isovolumetric ventricular contraction
D) ventricular ejection
E) isovolumetric ventricular relaxation

Question 51

Which factor has NO influence on the EDV?

A) time of ventricular diastole
B) arterial blood pressure
C) venous return
D) blood volume

Question 52

The cardiac cycle proceeds in a series of 5 phases. Identify the phases of cardiac cycle for the state atrial diastole, ventricular diastole. Select all that apply.

A) passive ventricular filling
B) atrial contraction
C) isovolumetric ventricular contraction
D) ventricular ejection
E) isovolumetric ventricular relaxation

Question 53

Which statement correctly describes events during cardiac cycle?

A) Atrial systole immediately follows the ventricular systole.
B) At least one pair of cardiac valves is closed in every phase of the cardiac cycle.
C) Blood flows through the heart in every phase of the cycle.
D) The pressure in the ventricles is always higher than the pressure in the atria.

Question 54

ST segment on the ECG trace is measured from

A) the end of the QRS complex to the end of T wave
B) the end of QRS to the beginning of T wave
C) the beginning of QRS to the end of T wave
D) the beginning of QRS the end of T wave

Question 55

The cardiac cycle proceeds in a series of 5 phases. Identify the phase of cardiac cycle for the state when atria are in systole, and ventricles in diastole.

A) passive ventricular filling
B) atrial contraction
C) isovolumetric ventricular contraction
D) ventricular ejection
E) isovolumetric ventricular relaxation

Question 56

Calcium influx into cardiac contractile fibers is responsible for all the following EXCEPT

A) the plateau phase of action potential
B) the depolarizing phase of action potential
C) Ca²⁺ release from the sarcoplasmic reticulum
D) exposing myosin binding sites on actin

Question 57

In the ECG what does the P-wave represent?

A) depolarization of the atria
B) repolarization of the atria
C) hyperpolarization of the bundle branches
D) repolarization of left ventricle

Question 58

If QRS complex and T wave represent depolarization and repolarization of ventricles respectively; why is T wave wider and smaller than QRS complex?

A) because QRS complex represents force of contraction
B) because repolarization is slower than depolarization
C) because T wave is a composite of depolarization of atria and ventricles
D) because QRS complex is a composite of depolarization of atria and ventricles

Question 59

In cardiac muscle cells, what cellular mechanism is responsible for generating force of contraction?

A) interaction between tropomyosin, troponin and myosin filaments
B) formation of cross bridges between myosin heads and actin
C) shortening of tropomyosin filaments
D) actin pulling the intercalated discs together

Question 60

On an electrocardiogram, which wave represents the repolarization of muscle cells of the ventricles?

A) P wave
B) QRS complex
C) T wave
D) R wave

Question 61

Which statement accurately describes the influence exercise has on the resting cardiac output?

A) An athlete has about the same resting cardiac output as a healthy untrained person of the same size because when the stroke volume increases the heart rate will decrease.
B) An athlete has a higher resting cardiac output than a healthy untrained person of the same size because both stroke volume and heart rate increase as a result of training.
C) An athlete has a lower resting cardiac output than a healthy untrained person of the same size because both stroke volume and heart rate decrease as a result of training.
D) An athlete has about the same resting cardiac output as the healthy untrained person of the same size because stroke volume decreases and heart rate increases once the exercise stops.

Question 62

Epinephrine is often administered in the emergency room to patients admitted to the hospital as a result of the accident. Administration of epinephrine has

A) negative ionotropic effect
B) positive chronotropic effect
C) negative effect on afterload
D) negative effect on O₂ saturation

Question 63

Athletes experience the decrease of the resting heart rate as their fitness increases. This so called resting bradycardia is the result of

A) decreased sympathetic activity decrease in cardiac motor neurons activity
B) decreased oxygen consumption
C) compensation for increased stroke volume
D) damage to the heart from too much of exercise

Question 64

The first heart sound (lubb) is associated with which of the events listed?

A) opening of the semilunar valves
B) opening atrioventricular valves
C) closure of the atrioventricular valves
D) closure of the semilunar valves

Question 65

Approximately how many cardiac cycles does the heart complete each day?

A) 1
B) 1,000
C) 10,000
D) 100,000

Question 66

What is true about right and left side of the heart during cardiac cycle?

A) both right and left ventricles develop the same pressure
B) both right and left sides of the heart pump the same amount of blood
C) left side of the heart contracts before the right side does
D) right ventricle develops higher force of contraction than the left

Question 67

Select the appropriate relationship between the valves opening and closing and pressure changes during the cardiac cycle.

A) semilunar valves begin to open when the pressure in the ventricles exceed diastolic blood pressure in the aorta or pulmonary artery
B) semilunar valves begin to open when the pressure in the ventricles exceed systolic pressure in the aorta or pulmonary artery
C) atrioventricular valves begin to open when the pressure in the ventricles exceeds the pressure in the atria
D) atrioventricular valves begin to close when the pressure in the aorta or pulmonary artery exceeds the pressure in the ventricles

Question 68

Binding of epinephrine to β1 adrenergic receptors in the heart causes

A) production of second messengers that activate protein kinase A and phosphorylation of myosin heads
B) inhibition of Ca²⁺ ATPase in the sarcoplasmic reticulum and decreased Ca²⁺ uptake
C) opening of voltage gated Na⁺ channels and depolarization
D) no effect, heart does not have functional β1 receptors

Question 69

What type of receptor is involved in the positive ionotropic effect of epinephrine or norepinephrine on the heart contractility?

A) G protein coupled receptor
B) receptor tyrosine kinase
C) ion channel receptor
D) intracellular receptor

Question 70

When the heart rhythm speeds up or slows down, which phase of cardiac cycle is affected more than others?

A) passive ventricular filling
B) atrial contraction
C) isovolumetric ventricular contraction
D) ventricular ejection
E) isovolumetric ventricular relaxation

Question 71

To maintain cardiac output adequate to the metabolic needs of the body in case of heavy blood loss the heart would

A) speed up its contraction rate
B) increase the contractility of heart muscle
C) simultaneously speed up its contraction rate and increase the contractility of heart muscle
D) the cardiac output will decrease and only the transfusion of blood can help

Question 72

The strength of cardiac muscle contraction for a particular preload (ionotropic effect) is regulated by

A) degree of activation of motor neurons
B) level of amino acids in blood
C) level of calcium in blood
D) presence or absence of inflammatory mediators

Question 73

How does atherosclerosis increase afterload?

A) because it dilates the arteries and lowers blood pressure
B) because it causes the semilunar valves to close too early
C) because it narrows the arteries and increases the blood pressure
D) because it increases the venous return volume

Question 74

Which of the following factors is responsible for increase of cardiac output during aerobic exercise?

A) increased arterial blood pressure
B) decreased venous return
C) increased preload
D) increased heart filling time

Question 75

What would be the effect of dehydration on the stroke volume and why?

A) It would decrease stroke volume because of lower preload.
B) It would increase stroke volume because of the higher afterload.
C) It would decrease stroke volume because of increased the EDV.
D) It would increase stroke volume because of decreased contractility.

Question 76

Patients with heart failure may be prescribed a beta blocker for their conditions. How is this useful? Inhibition of β adrenergic receptors in the heart causes

A) increase of heart contraction force
B) decrease of heart contraction force
C) no change in heart contraction force

Question 77

Why does the heart muscle go through the period of isovolumetric ventricular contraction?

A) to increase the contractility of the ventricles
B) to develop enough pressure to overcome the pressure in the aorta
C) to "top up" volume of blood in the ventricles by contracting the atria
D) to give time to the electrical impulses to spread and depolarize the muscle

Question 78

Ach secreted from the synapses of the parasympathetic nerve endings in the heart causes

A) an increase of the duration of the action potential in SA node
B) lower amplitude of action potential in SA node
C) hyperpolarization of cells in SA node
D) conduction to speed up between atria and ventricles

Question 79

Which of the following is the cause of stroke volume increase during intense physical activity

A) the increase of end diastolic volume
B) the elongation of filling time of the ventricles
C) the increase of the heart rate
D) the decrease of venous return

Question 80

Deep breathing is one of the nonpharmacological ways to increase activity in the vagus nerve. Activation of vagus nerve leads to

A) higher ATP consumption be the heart muscle
B) irregular heart beat
C) decrease of the heart rate
D) increased force of contraction in the heart