PHYSIO-LEC-LE-3-Feed-CSV-2023-and-2024 Flashcards
1
Q
- Which of the ff ions is involved in contraction
A. Intracellular Calcium
B. Extracellular Calcium
C. Intracellular Potassium
D. Extracellular Sodium
A
A. Intracellular Calcium
2
Q
- One of these is correct pairing of action potential phase and ion involved
A. Phase 0 : K+ influx
B. Phase 1: K+ efflux
C. Phase 2: Na+ influx
D. Phase 3: Ca++ efflux
A
B. Phase 1: K+ efflux
3
Q
- This process occurs during phase 3 in the action potential
A. Ca++ channels close; K channels open
B. Ca++ channels open; K channels close
C. Na+ channels open; K channels close
D. Both Na+ and Ca++ channels open
A
A. Ca++ channels close; K channels open
4
Q
- One of this process is responsible for prolonging the duration of cardiac action potential
A. Efflux of Na+
B. Efflux of K+
C. Influx of Ca++
D. Influx of K+
A
C. Influx of Ca++
5
Q
- Which of this occurs during myocardial contraction?
A. Ca++ bind to Troponin C
B. Efflux of Ca++ thru Na+Ca++ antiporter
C. Inhibition of Troponin I by Ca++
D. Re-uptake of Ca++ by sarco reticulum
A
A. Ca++ bind to Troponin C
6
Q
- One of these processes occurs during cardiac muscle relaxation.
A. Release of Ca++ from sarco reticulum
B. Blocking of myosin binding sites to actin
C. Phosphorylation of MLCK
D. Binding of ATP to myosin heavy chains
A
B. Blocking of myosin binding sites to actin
7
Q
- S2 (second heart sound) is heard during this phase of cardiac cycle.
A. Isovolumic contraction
B. Isovolumic relaxation
C. Rapid filling
D. Rapid ejection
A
B. Isovolumic relaxation
8
Q
- One of this is associated with isovolumic contraction
A. Aortic valve closes; mitral valve opens
B. Aortic valve opens; mitral valve closes
C. Pulmo valve closes; tricuspid valve opens
D. Pulmo valve opens; tricuspid valve closes
A
B. Aortic valve opens; mitral valve closes
9
Q
- What happens to cardiac pressure and volume during rapid filling phase of the cardiac cycle?
A. Ventricular pressure & volume increases
B. Ventricular pressure & volume decreases
C. Ventricular pressure decreases; ventricular volume increases
D. Ventricular pressure increases; ventricular volume decreases
A
C. Ventricular pressure decreases; ventricular volume increases
10
Q
- The A wave to the jugular venous curve is associated with?
A. Atrial contraction
B. Atrial relaxation
C. Atrial repolarization
D. Atrial hyperpolarization
A
A. Atrial contraction
11
Q
- The Amount of blood ejected during systole of ventricles
A. Cardiac output
B. Ejection fraction
C. End systolic volume
D. Stroke volume
A
D. Stroke volume
12
Q
- Which of these valves prevent backflow from the ventricles to the atria?
A. Aortic and pulmonic
B. Aortic and mitral
C. Mitral and tricuspid
D. Pulmonic and tricuspid
A
C. Mitral and tricuspid
13
Q
- Semilunar valves are important because they:
A. Prevent backflow of blood from the artery to the atrium during systole
B. Prevent backflow of blood from the artery to the ventricles during diastole
C. Prevent backflow of blood from the artery to the ventricles during systole
D. Prevent backflow of blood from the artery to the atrium during diastole
A
B. Prevent backflow of blood from the artery to the ventricles during diastole
14
Q
- Difference between Semilunar valves and Atrio-ventricular valves:
A. AV valves facilitate more blood going into the ventricles
B. Semilunar valves are subjected to greater mechanical abrasion
C. Semilunar valves contain chordae tendinae
D. AV valves suddenly closes due to high pressure in the arteries at the end of systole
A
A. AV valves facilitate more blood going into the ventricles
B. Semilunar valves are subjected to greater mechanical abrasion
15
Q
- Which of these is the mechanism of S1?
A. Oscillation of blood in arterial walls
B. Oscillation of blood in ventricular walls
C. Vibration of arterial walls
D. Vibration of ventricular walls
A
D. Vibration of ventricular walls
16
Q
- The force that stretches the relaxed muscle fibers
A. Afterload
B. Diastole
C. Preload
D. Stroke volume
A
C. Preload
17
Q
Frank-Starling mechanism is shown in one of these:
A. Stretch of the right atrial wall decreases heart rate
B. An increase in left ventricular and diastolic volume increases stroke volume
C. The intrinsic ability of the heart to adapt to increasing and decreasing volumes of outflowing blood
D. Within physiological limits, the heart pumps all the blood that returns via arteries
A
B. An increase in left ventricular and diastolic volume increases stroke volume
18
Q
Difference between fast response and slow response action potential
A. Fast response has more prolonged phase 2
B. Fast response has less negative RMP
C. Slow response has steeper upstroke slope
D. Slow response has an early phase 3
A
A. Fast response has more prolonged phase 2
19
Q
Characteristic feature of Slow response action potential responsible for slow conduction of Action potential
A. Greater amplitude of Action potential
B. Steeper slope of Action potential
C. Faster Action potential
D. Smaller Action potential
A
D. Smaller Action potential
20
Q
Which of this will result in Sinus Tachycardia?
A. Delay of Action potential in AV node
B. Less negative threshold potential
C. More negative threshold potential
A
C. More negative threshold potential
21
Q
Conduction velocity of action potential decreases when there is:
A. More negative RMP
B. Decreased intervals of Action potentials
C. Slower rate of phase 0
D. An early conduction of phase 3
A
C. Slower rate of phase 0
22
Q
Which of these is/are the mechanism/s of pacemaker shift?
A. Blockade of impulse transmission in conducting system.
B. The intrinsic mechanism for vascular smooth muscle contraction
C. Refers to the delayed AV conduction of the heart to allow enough filling time
D. None of the choices
A
A. Blockade of impulse transmission in conducting system.
23
Q
Vagal stimulation leads to conduction delay by?
A. Decreasing Parasympathetic response
B. Increasing Na+ permeability of the membrane
C. Increasing Ca++ permeability of the membrane
D. Increasing K+ permeability of the membrane
A
D. Increasing K+ permeability of the membrane
24
Q
Effect of Stimulation B-1 receptor is to produce?
A. Cardiac arrhythmia
B. Bradycardia
C. Tachycardia
D. Wide pulse pressure
A
C. Tachycardia
25
25. What is the mechanism of sinus nodal rhythmicity?
A.Less negative resting membrane potential of SA node.
B. Less negative resting threshold potential of SA node.
C. More negative resting membrane potential of SA node.
D. More negative resting threshold potential of SA node.
A.Less negative resting membrane potential of SA node.
26
26. What is associated with rapid blood flow?
A. High blood viscosity
B. Long narrow blood vessels
C. Narrow pressure difference
D. Short wide blood vessels
D. Short wide blood vessels
27
The most important factor that affects vascular resistance is?
Radius of the blood vessel
28
Which of these blood vessels have the slowest velocity of blood flow?
A. Arteries due to its low compliance
B. Aorta due to its diameter
C. Capillaries because of large cross-sectional area
D. Veins because of its low pressure
C. Capillaries because of large cross-sectional area
29
One of this condition results in Turbulent blood flow:
A. Absence of eddy currents
B. Pulsatile nature of blood flow
C. Parabolic flow along the lumen
D. Steady rate of blood flow
B. Pulsatile nature of blood flow
30
Compared to turbulent blood flow, laminar blood flow has one of these characteristics:
A. Presence of obstruction
B. Flow of blood along rough surfaces and edges
C. Parabolic blood flow at the periphery of the lumen
D. Central stream of blood moves rapidly
D. Central stream of blood moves rapidly
31
Based on Poiseuille’s law, one of these conditions is associated w slow blood flow:
A. Hemorrhage
B. Anemia
C. Thrombocytopenia
D. Polycythemia
D. Polycythemia
32
High blood pressure is associated with:
A. Arterial constriction
B. Arterial dilation
C. Decreased venous return
D. Decreased transmural pressure
A. Arterial constriction
33
Pulse pressure increases when high in
A. Compliance
B. Diastolic pressure
C. Conductance velocity
D. Stroke volume
D. Stroke volume
34
Which of these conditions will result in low Central venous pressure
A. Increased Cardiac contractility
B. Increased Cardiac output
C. Decreased preload
D. Decreased afterload
C. Decreased preload
35
Peripheral venous pressure is high in one of this condition:
A. Low Right Atrial pressure
B. High Right Atrial pressure
C. Low Left Atrial pressure
D. High Left Atrial pressure
B. High Right Atrial pressure
36
The most important factor that changes the diameter of blood vessels
A. Secretion of blood vessel metabolites
B. Contraction of the vascular smooth mm
C. ANS regulation
D. Myocardial contractility
B. Contraction of the vascular smooth mm
37
Outward movement of fluid into the interstitial space occurs when there is an increase in
A. Capillary hydrostatic pressure
B. Capillary colloid osmotic pressure
C. Interstitial hydrostatic pressure
D. Interstitial colloid osmotic pressure
A. Capillary hydrostatic pressure
38
Lymph flow increases when there is a decrease in
A. Interstitial hydrostatic pressure
B. Interstitial oncotic pressure
C. Plasma hydrostatic pressure
D. Plasma oncotic pressure
D. Plasma oncotic pressure
39
At the Arterial end of capillaries there is an outward movement of fluid because of
A. High capillary hydrostatic pressure
B. High capillary oncotic pressure
C. High interstitial hydrostatic pressure
D. None of the above
A. High capillary hydrostatic pressure
40
All of this will most likely cause peripheral edema except
A. Hypoalbuminemia
B. Muscle contraction
C. Proteinuria
D. All of the above
B. Muscle contraction
41
The metabolic factor and predominant regulator of _____ circulation
Cerebral
42
All of these will increase myocardial perfusion except:
Contraction of the myocardium
43
The primary function of cutaneous circ?
A. Supplies blood flow to mm during exercise
B. Maintain constant body temperature
C. Sympathetic nerve plays a minor role
D. Mechanical compression during systol
B. Maintain constant body temperature
44
One of these is characteristic feature of fetal circulation
A. The Ductus venosus by passes the liver and drains to the superior vena cava
B.Ductus arteriosus connects the pulmonary artery and aort
C. The foramen ovale shunts the blood from the inferior vena cava to the right atrium
D. All of the above
B.Ductus arteriosus connects the pulmonary artery and aort
45
One of these leads to a circulatory change in Newborn baby
A. Closure of umbilical vessels decreases total peripheral resistance
B. High arterial Oxygen pressure initiates the closure of ductus arteriosus
C. The increase in pulmonary resistance increases the left atrial pressure.
D. Reversal of the pressure gradient across the ventricles abruptly closes foramen ovale
B. High arterial Oxygen pressure initiates the closure of ductus arteriosus
46
Physiologic effect of contraction to smooth muscle of Arteries includes:
Increase Lumen Diameter
47
Mechanism of color change of fingers when placed in cold water
Interruption of blood flow
48
After cold exposure, bright red fingers are due to:
Accumulation of vasodilator metabolites
49
Which of the following is the normal response of cutaneous blood vessel to temperature?
A. Vasoconstriction and Vasodilation of Hot weather
B. Vasoconstriction and Vasodilation on Cold weather
C.Vasoconstriction to warming and vasodilation to cold
D.Vasodilation to warming and vasoconstriction to cold
D.Vasodilation to warming and vasoconstriction to cold
50
Which of the following is/are mediator/s of the response of cutaneous vessels
A.Postganglionic receptors transmit impulses to the higher centers of the brain
B.Peripheral temperature receptors transmit impulses to the anterior hypothalamus
C.Parasympathetic nervous response in maintaining the blood vessel ton
D.All of the above
B.Peripheral temperature receptors transmit impulses to the anterior hypothalamus
51
51.Effects of coronary artery occlusion on interstitial fluid, K+ concentration, resting membrane potential of myocardial cells in Ischemic cells is:
High K+ levels makes RMP less negative
52
52.One of this is the effect of altered RMP on impulse propagation
Slower propagation due to smaller amplitude of the Action potential
53
53.Effect of the increased Vagal Activity in the SA node is to:
Increase negativity of the RMP due to increase K+ conductance
54
54.Effect if increased Vagal activity on AV node conduction fibers is to:
Prolong AV conduction due to decreased Ca++ conductance
55
55.Re-entrant is associated with one of this altered impulse propagation
Slow conduction leads to unidirectional block
56
56.Which of the following statements best describes Nervous control of the Cardiovascular System?
A.Presence of stretch receptors located in the walls of carotid sinus
B.Increase in intrathoracic pressure decreases venous return
C.Decreased vasoconstriction results from an increased sympathetic outflow
D.Sympathetic nervous system enhances Atrial and Ventricular contractility
D.Sympathetic nervous system enhances Atrial and Ventricular contractility
57
57.What is the effect of stimulating the cerebral centers ventromedial region?
Decreases Arterial blood pressure
58
58.Which of the following statements best describes regulation of peripheral circ?
A.Blood flow is regulated by altering arteriolar pressure
B.Contraction of vascular smooth muscle is initiated upon stretch
C.Changes in perfusion pressure evokes changes in vascular resistance maintaining constant blood flow
D.None of the above
C.Changes in perfusion pressure evokes changes in vascular resistance maintaining constant blood flow
59
59.Which of the following conditions will result in an increased heart rate?
A.Initiation of Valsalva maneuver
B.Administration of beta blockers
C.Infusing blood/Saline (BAINBRIDGE)
D.All of the above
C.Infusing blood/Saline (BAINBRIDGE)
60
60.Which of the following conditions will increase myocardial contractility?
A.Infusion of Norepinephrine
B.Decreased phospholamban
C.Severe hypoxia
D.Hypercapnia
A.Infusion of Norepinephrine
61
61.Which of the following diseases will present with a decrease in myocardial contractility?
A. Hyperthyroidism
B. Emphysema
C. Addison’s disease
D. Hypopituitarism
D. Hypopituitarism
62
62.Which of the conditions would increase myocardial contractility?
A.Insulin resistance
B.Mild Hypoxia
C.Severe Hypoxia
Increased PaCO2 levels
B.Mild Hypoxia
63
63.Which of the following statements best describes autoregulation of blood flow?
Mediated by myogenic mechanism
64
64.Which of the following humoral factors contribute to Vasodilation?
Adenosine
65
65.Which of the following vascular controls has the least effect on cerebral and cardiac resistance vessels?
Sympathetic neural vasoconstriction
66
66.Which of the following is the principal means by which HR is controlled?
Autonomic Nervous system
67
67.Which of the following explains the rhythmic variation of HR during respiration?
Changes in Vagal activity
68
68.Which of the following conditions will increase Cardiac Output?
Normal inspiration
69
69.Which of the following statements does not describe the cardiac function curve. Cardiac output is dependent on:
Left ventricular end diastolic pressure
70
70.Which of the following factors results in the upward shift of cardiac function curve?
Increased contractility
71
71.Which of the following will cause a downward shift in the cardiac function curve?
Giving negative Inotropes
72
72. Which of the following effects are derived from the Cardiac function curve?
Increase in both stroke volume and cardiac output
73
73.Which of the following statements can be derived from the cardiac and vascular function curve?
Increased mean systemic filling pressure
74
74.Which of the following factors cause a change in Cardiac and Vascular function curve depicted by the dashed line?
Increased in blood volume
75
75.Which of the following effects is not seen on the Cardiac and Vascular function curve?
Increased Myocardial contractility
76
76.Which of the following controls the stimulation of skeletal muscles during exercise?
Local metabolic factors
77
77.Which of the following has profound effect in limiting exercise performance?
Delivery of blood to the active muscles.
78
78.Which of the following event is expected during exercise?
Reduction in total peripheral resistance increases venous return.
79
79.Which of the following decompensatory mechanism is involved during an acute blood loss?
Monocyte phagocytic system function is increased
80
80.Which of the following statements best describes the compensatory mechanisms during acute blood loss
Reduction of vagal tone and enhancement of sympathetic tone.
81
81.Which of the following statements is true?
ECG lead II detects the current running from the right arm lead to left leg lead.
82
82.One of the current leads which would detect the most accurate vector of the normal heart current
Lead II
83
83.Ectopic Foci in the Heart which emits abnormal contractions during cardiac cycle
PAC
84
84.P wave means
Atrial depolarization
85
85.An arrythmia wherein the QRS complex is considerably prolonged with a high voltage and T wave deflected in the opposite direction
Premature ventricular tachycardia
86
86.Which of the following bipolar ECG leads detect current on vertical plane
Leads II, III and aVf
87
87.Which of the following conditions can cause a deviation of the normal axis of the heart
Right ventricular hypertrophy can cause right axis deviation
88
88.Which of the ff is correct?
Tachycardia means an increase in heart rate above 100 bpm in adults.
89
89.This is true of the T wave
A.A positive deflection on ECG being a negative vector repolarization contraction
B.Represents atrial repolarization
C.Represents ventricular contraction
D.A negative deflection on ECG being a positive vector depolarization contraction
A.A positive deflection on ECG being a negative vector repolarization contraction
90
90.True of the augmented limb leads aVR, aVL, aVF.
They measure the resultant vector from the center of Einthoven’s triangle towards the right atrium, left arm, left leg limb leads electrode.
91
91.Results from cessation of all spontaneous electrical control signals in the heart.
Cardiac arrest
92
92.This occurs when propagating impulses fall to die out after normal activation of the cardiac muscles and persists to reexcite the heart after refractory period has ended.
Reentry phenomenon.
93
93.Electrical signal travels as a single large wave always in 1 direction around and around the atrial muscle mass
Atrial Flutter
94
94.Major direction of the overall electrical activity of the heart is the
Axis
95
95.The most serious cardiac arrhythmias wherein the cardiac impulses emanate from various sites of the ventricular muscle mass resulting in ineffective ventricular contraction
Ventricular fibrillation
96
96.True statement about the deflection seen in ECG:
Depolarization wave moving towards the positive electrode generates an upward deflection on the ECG
97
97.Which of the following is postulated to be the cause of most cardiac arrhythmias?
A.Starling Forces
B.Re entry Phenomenon
C.Automaticity
D.AOTA
B.Re entry Phenomenon
98
98.Einthoven’s triangle is form by which of the ff combination on ECG electrodes
Right arm lead, left arm lead, left leg lead
99
99.What is the heart rate on the above ECG tracing?
51 beats per minute
100
100.In the ECG tracing, the Lead I magnitude is -5 while the AVF is +8. What is the axis of the heart?
Right axis deviation
101
One of these occurs during diastole;
A. Ca2+ activates ryanodine receptor channels
B. Ca2+ enters myocytes
C. Ca2+ enters sarcoplasmic reticulum
D. Ca2+ interacts with troponin
Ca2+ enters sarcoplasmic reticulum
102
Compared to fast response action potentials, slow response action potentials occur in;
A. Atrial myocytes
B. Atrio-ventricular node
C. Purkinje fibers
D. Ventricular myocytes
Atrio-ventricular node
103
Conduction delay in the AV node is important because it;
A. Prevents effective myocardial ejection
B. Prevents repolarization of cardiac myocytes
C. Promotes effective atrial relaxation
D. Promotes optimal ventricular filling
Promotes optimal ventricular filling
104
One of these events occurs during period of ejection.
A. Aortic valve opens
B. Blood flows into ventricle
C. Ventricular pressure decreases
D. Ventricular volume increases
Aortic valve opens
105
Phase 0 of cardiac action potential is due to;
A. Efflux of K+
B. Efflux of Na+
C. Influx of K+
D. Influx of Na+
Influx of Na+
106
This phase of cardiac cycle coincides with R wave of the ECG:
A. Isovolumic contraction
B. Isovolumic relaxation
C. Rapid ejection
D. Rapid filling
Isovolumic contraction
107
A wave seen in jugular veins is due to;
A. Bulging of AV valves toward atria
B. Closure of tricuspid valve
C. Contraction of atria
D. Flow of blood into atria
Contraction of atria
108
Difference between fast response and slow response action potential includes;
A. Fast response has less negative phase 4
B. Fast response has no phase 1
C. Slow response has less prolonged phase 2
D. Slow response has more step 0
Slow response has less prolonged phase 2
109
Heart rate INCREASES when there is INCREASED;
A. Amplitude of action potential
B. Duration of phase 2
C. Rate of phase 0
D. Rate of slow diastolic depolarization
Rate of phase 0
110
Amount of blood ejected by ventricle during systole is;
A. Ejection fraction
B. End-diastolic volume
C. End-systolic volume
D. Stroke volume
Stroke volume
111
Phase of cardiac cycle that occurs after P wave of 12-lead ECG is;
A. Arial systole
B. Slow filling
C. Rapid filling
D. Ventricular systole
Arial systole
112
Funny channels of Na+ is important because it;
A. Carries Na+ out of SA nodal cells
B. Mediates slow diastolic depolarization
C. Opposes outward Ca2+ current
D. Repolarizes SA nodal cells after phase 0
Mediates slow diastolic depolarization
113
One of these ionic currents mediate slow diastolic depolarization of cardiac action potentials;
A. ATP-driven Ca2+ pump
B. Inward Na+ current
C. Na+ - Ca2+ exchange
D. Outward Ca2+ current
Na+ - Ca2+ exchange
114
Venous blood returning to atria and released into ventricles occurs during;
A. Isovolumic contraction
B. Isovolumic relaxation
C. Rapid ejection
D. Rapid filling
Rapid filling
115
The amplitude of cardiac action potential is dependent on;
A. Ca2+ influx
B. K+ efflux
C. K+ influx
D. Na+ influx
Na+ influx
116
Difference between semilunar and atrio-ventricular valves;
A. Absent chordae tendinae in AV valves
B. Rapid closure of semilunar valves
C. Slow ejection of blood through semilunar valves
D. Small openings of AV valves
Rapid closure of semilunar valves
117
Which of these processes is involved in excitation-contraction coupling during systole?
A. Ca2+ dissociates from troponin C
B. Ca2+ troponin complex inhibits troponin I on actin
C. Myosin blocks myosin binding site on actin
D. Myosin interacts with active site on actin
Myosin interacts with active site on actin
118
Rapid ejection phase of cardiac cycle has one of these characteristics.
A. Decrease in aortic blood flow
B. Decrease in ventricular pressure
C. Increase in aortic pressure
D. Increase in ventricular volume
Increase in ventricular volume
119
Opening of tricuspid valves cut during ___ phase of cardiac cycle;
A. Isovolumic contraction
B. Isovolumic relaxation
C. Rapid ejection
D. Rapid filling
Isovolumic contraction
120
Mechanism of vagal effects on the heart is;
A. Depolarization of membrane due to rapid Na+ influx
B. Hyperpolarization of membrane due to rapid K+ efflux
C. Reduction of membrane permeability to K+
D. Stimulation of diastolic depolarization due to Na+ funny channels
Hyperpolarization of membrane due to rapid K+ efflux
121
The second heart sound is heard during ___ phase of cardiac cycle;
A. Isovolumic contraction
B. Isovolumic relaxation
C. Rapid ejection
D. Rapid filling
Isovolumic contraction
122
Slow response action potentials are prone to conduction block because;
A. Amplitude is small
B. Phase 1 is absent
C. Phase 2 is prolonged
D. Threshold potential is low
Amplitude is small
123
One of this is a characteristic feature of phase 3 of cardiac action potential;
A. Efflux of K+ exceeds influx of Ca2+
B. Efflux of Na+ initiates repolarization
C. Influx of Ca2+ exceeds efflux of K+
D. Influx of K+ initiates repolarization
Efflux of K+ exceeds influx of Ca2+
124
Heart sound heart best at the 5th intercostal space, left mid-clavicular line is associated with closure of;
A. Aortic valve
B. Mitral valve
C. Pulmonic valve
D. Tricuspid valve
Mitral valve
125
Phase 0 of slow response action potential is produced by;
A. Efflux of Ca2+ through L-Cha RLD
B. Efflux of Na+ through fast voltge-activated Na+ channels
C. Influx of Ca2+ through L-Ca2+ channels
D. Influx of Na+ through fast voltage-activated Na+ channels
Influx of Ca2+ through L-Ca2+ channels
126
An increase in extracellular potassium levels can cause;
A. A decrease in heart rate
B. An increase in force of contraction
C. An increase in stroke volume
D. All of the choices are correct
A decrease in heart rate
127
Increased parasympathetic stimulation of the heart.
A. Increases cardiac output
B. Increase the force of ventricular contraction
C. Decreases heart rate
D. Increases the rate of depolarization in the SA node
Decreases heart rate
128
T waves on an ECG represent.
A. Depolarization of the ventricles
B. Repolarization of the atria
C. Depolarization of the atria
D. Repolarization of the ventricles
Repolarization of the ventricles
129
Purkinje fibers;
A. Conduct impulses much more slowly than ordinary cardiac muscle
B. Connect the SA node and the AV node
C. Conduct action potentials through the atria
D. Specialized cardiac muscle cells
E. Ensure that ventricular contraction starts at the base of the heart
Specialized cardiac muscle cells
130
Given these structures of the conducting system of the heart: (1) atrioventricular bundle, (2) AV node, (3) bundle branches, (4) Purkinje fibers and (5) SA node. Choose the arrangement that potential passes through them.
A. 52134
B. 25314
C. 25134
D. 25413
52134
131
During the transmission of action potentials through the conducting system of the heart, there is a temporary delay at the;
A. Bundle branches
B. AV node
C. AV bundle
D. Purkinje fibers
E. SA node
AV node
132
Cardiac pacemaker muscle cells are autorhythmic because;
A. They spontaneously develop action potentials
B. There is a delay between atrial and ventricular stimulation
C. They produces action potential the fastest
D. There is a plateau at phase 2 of the action potential
They spontaneously develop action potentials
133
Which of the following is necessary for the heart to effectively function as a pump?
A. Almost simultaneous contraction of the ventricular muscles
B. Prolongation of phase 2 of the cardiac action potential
C. The ventricle contracts ahead of the atria by 1/6 of a second
D. Closure of aortic and pulmonic valves during systole
Almost simultaneous contraction of the ventricular muscles
134
Which of the following characteristics give the cardiac pacemaker is responsible for the autoregeneration of action potential?
A. Balancing of countercurrent mechanisms between potassium and calcium
B. Constant outward movement of potassium through rectifier channels
C. Presence of leaky sodium and calcium ion channels
D. Opening of fast sodium ion channels during phase 0 of the cardiac cycle
Presence of leaky sodium and calcium ion channels
135
True about the resting membrane potential of sinus nodal fibers;
A. Less excitable than ventricular muscle fibers due to lower negativity
B. Less negative than other cardiac muscle and conductive fibers
C. All of the statements are true
D. Maintained at -85 to -90 mV
Less negative than other cardiac muscle and conductive fibers
136
Which of the following prevents cardiac action potential in the atria to immediately cause depolarization of the ventricular muscles?
A. Less gap junctions in tissues after the cardiac pacemaker
B. Atrioventricular node
C. Atrioventricular fibrous tissue
D. Anterior interatrial band
Atrioventricular fibrous tissue
137
Total time for transmission of the cardiac impulse from the initial bundle branches to the last of the ventricular muscle fibers in the normal heart.
A. 0.4 seconds
B. 0.7 msec
C. 0.6 seconds
D. 0.5 msec
0.6 seconds
138
Discharge rate per minute of the atrioventricular node.
A. 70-80 beats per minute
B. 40-60 beats per minute
C. 80-100 beats per minute
D. 15-40 beats per minute
40-60 beats per minute
139
Major consequence of ectopic pacemakers.
A. The apical muscles tend to contract first
B. The pacemaker is elsewhere than the sinoatrial node
C. Ineffective pump function due to abnormal sequence of contraction of cardiac muscles
D. There is simultaneous contraction of both ventricles
Ineffective pump function due to abnormal sequence of contraction of cardiac muscles
140
Electrical balance in the cardiac action potential occurs in which phase?
A. Phase 1
B. Phase 3
C. Phase 2
D. Phase 0
Phase 2
141
Normal resting membrane potential of cardiac myocytes.
A. -70 mV
B. -90 mV
C. -60 mV
D. -80 mV
-90 mV
142
Threshold for excitation of cardiac myocytes.
A. -60 mV
B. -90 mV
C. -80 mV
D. -70 mV
-70 mV
143
True about the principle of electrocardiography.
A. The ECG tracing is a vector representation of the cardiac action potential as it travels along the conductive pathways
B. Chest leads measure potential differences along the coronal or vertical plane of the heart.
C. The resulting tracing represents the pahses of the cardiac action potential.
D. Limb leads are composed of 6 physical electrodes detecting potential differences along the vertical plane of the heart.
The ECG tracing is a vector representation of the cardiac action potential as it travels along the conductive pathways
144
This type of arrhythmia is a result of action potentials travelling around within the atrium causing repeated atrial depolarization.
A. Atrial fibrillation
B. Atrial flutter
C. Sinus node activation
D. Ectopic pacemaker
Atrial flutter
145
Cessation of all electrical signals of the heart is represented on ECG as:
A. Flat line on all leads
B. QRS without preceding P wave
C. Atrial P wave but without QRS-T
D. PR interval of more than 0.2 seconds
Flat line on all leads
146
A dropped beat in second degree AV block is described as;
Atrial P wave but no QRS-T wave
QRS without preceding P wave
PR interval of more than 0.2 seconds
P wave occurs too soon in the ECG tracing
Atrial P wave but no QRS-T wave
147
Which of the following statements is/are true about the ECG tracing?
A. In a standardization of 10mm=1mV, 10 small squares would correspond to 10 mV
B. An RR interval of 35 small squares is equal to a heart rate of 90 beats per minute
C. The P wave preceding the QRS wave represents ventricular repolarization
D. In standard rate of 25mm/sec tracing, 5 small squares is equal to 0.04 sec.
In standard rate of 25mm/sec tracing, 5 small squares is equal to 0.04 sec.
148
Which of the following are true of contiguous ECG limb leads?
A. All of the statements are true
B. Precordial leads V1, V2, V3, V4, V5 and V6 represent the anteroseptal wall supplied by the left circumflex artery
C. Leads II, III and avF represents the heart’s inferior wall supplied by the right coronary artery
D. Lead I and aVL represents the heart’s lateral wall together with precordial leads V1 and V2.
Leads II, III and avF represents the heart’s inferior wall supplied by the right coronary artery
149
Among the ECG leads which on best represents the flow of current in the heart?
A. Limb lead II
B. Limb lead I
C. Limb lead III
D. Limb lead IV
Limb lead II
150
The mean direction of action potentials traveling through the ventricles during ventricular depolarization is determined on ECG by which of the following?
A. Presence of P wave
B. Regularity of the P and RR interval
C. Heart axis
D. Height of the T wave
Heart axis
151
1.Which of the following statements regarding blood pressure measurement is correct?
A.As inflation pressure approaches the diastolic level, the Korotkoff sounds start to appear.
B.Systolic pressure may be estimated by palpation of the brachial artery.
C.If the inflation pressure is above the systolic level, no blood passes through the brachial artery.
D.Korotkoff sounds start to disappear when inflation pressure falls just below the systolic level
C.If the inflation pressure is above the systolic level, no blood passes through the brachial artery.
152
2.Which of the following metabolites autoregulate blood flow to the brain?
A.CO2
B.O2
C.Adenosine
D.Lactate
A.CO2
153
3.Which of the following decompensatory mechanisms is invoked during an acute blood loss?
A.Acidosis stimulates the heart
B.Initial phase of hypocoagulability
C.MPS function is increased
D.Myocardial contractility is depressed
D.Myocardial contractility is depressed
154
4.Which statement best describes autoregulation of blood flow.
A.Maintains constant pressure despite changes in blood flow.
B.Mediated by a myogenic mechanism
C.Increase in transmural pressure elicits a dilatation of vascular smooth muscle
D.Dependent on the endothelium
B.Mediated by a myogenic mechanism
155
5.Which of the following conditions is not expected when there is an increase in arteriolar resistance?
A.Step up in the afterload
B.Rise in capillary filtration
C.Elevation in arterial pressure
B.Rise in capillary filtration
156
6.Which of the following statements best describes the nervous control of the cardiovascular system?
A.Effect of stimulation of cholinergic fibers on total vascular resistance is large
B.Regulation of the peripheral circulation is achieved mainly by the parasympathetic nervous system
C.Sympathetic nervous activity enhances atrial and ventricular contractility
D.Intrinsic heart rate prevails after complete synthetic blockade
C.Sympathetic nervous activity enhances atrial and ventricular contractility
157
7.Which of the following factors is the major regulator of coronary blood flow?
A.Aortic pressure
B.Coronary resistance
C.Extravascular compression
D.Blood viscosity
A.Aortic pressure
158
8.Which of the following area in the vascular system has the highest systolic blood pressure?
A.Renal artery
B.Central vein
C.Aorta
D.Pulmonary artery
A.Renal artery
159
9.Which of the following variables can be used interchangeably to label the x-axis in a cardiac and vascular function curve?
A.Mean systemic filling pressure
B.Pulse pressure
C.End-diastolic volume
D.End-systolic volume
C.End-diastolic volume
160
10.Which of the following compensatory changes should occur when a person moves from a supine position to a standing position?
A.Increase sympathetic outflow resulting to increased contractility
B.Decreased venous return contributing to decreased cardiac output
C.Decrease parasympathetic outflow leading to a decreased heart rate
D.Activation of the vasomotor center resulting to decreased total peripheral resistance
A.Increase sympathetic outflow resulting to increased contractility
161
11.Which of the following medications can cause the phenomenon coronary steal?
A.Dypiridamole
B.Carvediol
C.Isosorbide dinitrate
D.Verapamil
A.Dypiridamole
162
12.What will be the effect of stimulating the cerebral centers caudal and ventromedial to the pressor region?
A.Decreases arterial blood pressure
B.Accelerates heart rate
C.Vasoconstriction
D.Enhances myocardial contractility
A.Decreases arterial blood pressure
163
13.Which of the following conditions would increase myocardial contractility?
A.Infusion of norepinephrine
B.Inspiration
C.Cholinergic stimulation
D.Severe hypoxia
A.Infusion of norepinephrine
164
14.Which of the following humoral factors contribute to vasodilatation?
A.Endothelin
B.Vasopressin
C.Angiotensin II
D.Adenosine
D.Adenosine
165
15.Which of the following intracellular concentrations of ions is best correlated with myocardial contractility?
A.Ca2+
B.Na+
C.Mg2+
D.K+
A.Ca2+
166
16.Which of the following events is expected to occur during exercise?
A.Vagus nerve impulse are stimulated resulting to an increase in heart rate and myocardial contractile force
B.Reduction in total peripheral resistance increases venous return
C.Vascular resistance decreases in the skin, kidneys, splanchnic regions, and inactive muscles
D.Sympathetic nervous system is inhibited
B.Reduction in total peripheral resistance increases venous return
167
17.Which of the following conditions will increase cardiac output?
A.Severe hypoxemia
B.Hypertension
C.Supraventricular tachycardia
D.Normal inspiration
D.Normal inspiration
168
18.Which of the following receptors would decrease the heart rate when stimulated?
A.Muscarinic receptors
B.α1 receptors
C.β1 receptors
D.β2 receptors
A.Muscarinic receptors
169
19.Which of the following predominates in the control of circulation of the skeletal muscles during exercise?
A.Parasympathetic nervous system
B.Sympathetic nervous system
C.Autoregulation
D. Local metabolic factors
D. Local metabolic factors
170
20.Which of the following statements is true regarding the venous system?
A.Gravitational forces have no influence in the amount of blood in the venous system
B.Veins are very distensible and have very high resistance to blood flow
C.Muscular contraction promotes venous pooling and increases capillary hydrostatic pressure flow
D. After standing up, the slowness in the rise in venous pressure is attributable to the venous valves
D. After standing up, the slowness in the rise in venous pressure is attributable to the venous valves
171
21.Which of the following parameters is expected to decrease if the ejection fraction was increased?
A.End-systolic volume
B.Stroke volume
C.Cardiac output
D.End-diastolic volume
A.End-systolic volume
172
22.Which of the following would demonstrate increase in myocardial contractility by the Frank-Starling relationship?
A.Decreased cardiac output for a given end-diastolic volume
B.Increased cardiac output for a given end-diastolic volume
C.Decreased cardiac output for a given end-systolic volume
D.Increased cardiac output for a given end-systolic volume
B.Increased cardiac output for a given end-diastolic volume
173
23.Which of the following diseases would present with a decrease in myocardial contractility?
A.Insulinoma
B.Hyperthyroidism
C.Hypopituitarism
D.Glucagonoma
C.Hypopituitarism
174
24.Which of the following explains the rhythmic variation in heart rate during respiration?
A.Changes in sympathetic activity
B.Changes in both vagal and sympathetic activity
C.No relationship with the change in vagal or sympathetic activity
D.Changes in vagal activity
D.Changes in vagal activity
175
25.Which of the following conditions would increase myocardial contractility?
A.Acidosis
B.Mild hypoxia
C.Severe hypoxia
D.Hypercapnia
B.Mild hypoxia
176
26.Which of the following would explain the physiologic response to embarrassment or anger?
A.Cerebral stimulation of the sympathetic nerve
B.Stimulation of temperature-regulating centers in the anterior hypothalamus
C.Cerebral inhibition of the sympathetic nerve
D.Cold-induced shift of the oxyhemoglobin dissociation curve to the left
B.Stimulation of temperature-regulating centers in the anterior hypothalamus
177
27.Which of the following mechanisms would explain the increase in myocardial contractility when increasing heart rate?
A.More Ca2+ ions enter the cell during each action potential
B.Increasing the storage of Ca2+ by the sarcoplasmic reticulum
C.Increasing entry of more Ca2+ during the plateau
D.Inhibiting the Na+-K+ pump
A.More Ca2+ ions enter the cell during each action potential
178
28.Which of the following is true of the circulatory changes that occur at birth?
A.Closure of the umbilical vessels increases total peripheral resistance and the arterial blood pressure
B.Continuation of blood flow to umbilical vein because ductus venosus remains open closes
C.Thickness of the right ventricle is greater than the left ventricle
D.Increased in pulmonary vascular resistance as the lungs fill with air
A.Closure of the umbilical vessels increases total peripheral resistance and the arterial blood pressure
179
29.Which of the following would explain the fall in arterial pressure upon standing up in a person who has had a sympathectomy?
A.An exaggerated response of the brainbridge reflex
B.An exaggerated response of the baroreceptor mechanism
C.A suppressed response of the brainbridge reflex
D.A suppressed response of the baroreceptor mechanism
D.A suppressed response of the baroreceptor mechanism
180
30.Which of the following statements does NOT describe the cardiac function curve?
A.Cardiac output is dependent on right ventricular end-diastolic pressure
B.Cardiac output is dependent on central venous pressure
C.Cardiac output is dependent on right atrial pressure
D.Cardiac output is dependent on left ventricular end pressure
D.Cardiac output is dependent on left ventricular end pressure
181
31.Which of the following has a profound effect in limiting exercise performance?
A.O2 consumption of the muscles
B.Delivery of blood to the active muscles
C.Blood O2 extraction
D.Arterial O2 saturation
B.Delivery of blood to the active muscles
182
32.Which of the following compensatory mechanisms is expected to occur when a person stands from a supine position?
A.Increase contractility
B.Decrease total peripheral resistance (TPR)
C.Decrease cardiac output
D.Decrease in heart rate
A.Increase contractility
183
33.Which of the following condition would explain the drop in pressure that occurs across the arterioles?
A.The velocity of blood flow through arterioles is the highest
B.The arterioles have the greatest resistance
C.Arterioles have the greatest surface area
D.Arterioles have the greatest cross-sectional area
B.The arterioles have the greatest resistance
184
34.Which of the following statements best describe the compensatory mechanisms during an acute blood loss?
A.NaCl and water excretion is increased
B.Reduction of vagal tone and enhancement of sympathetic tone
C.Threshold for stimulation of baroreceptors is at an arterial pressure of 40 mmHg
D.Direction of the secondary changes in pressure is toward the direction of the initiating change
B.Reduction of vagal tone and enhancement of sympathetic tone
185
35.Which of the following vascular controls has the least effect on the cerebral and cardiac resistance vessels?
A.Metabolic regulation
B. Endothelium-mediated
C.Sympathetic neural vasoconstriction
Myogenic regulation
C.Sympathetic neural vasoconstriction
186
36.Which of the following is the principal means by which heart rate is controlled?
A.Autonomic nervous system
B.Brainbridge reflex
C.Baroreceptor reflex
Chemoreceptors
A.Autonomic nervous system
187
37.Which of the following statements is true regarding pulse pressure?
A.Decreases with aging due to a decrease in capacitance of the arteries
B.Determined by the cardiac output
C.Difference between mean arterial pressure and central venous pressure
D.Determined by the difference between end-diastolic volume and end-systolic volume
D.Determined by the difference between end-diastolic volume and end-systolic volume
188
38.Which of the following statements best describes the regulation of peripheral circulation?
A.Low concentrations of epinephrine constrict resistance vessels
B.Adequate O2 supply prompts the formation of vasodilator metabolites
C.Changes in perfusion pressure evoke changes in vascular resistance maintaining constant blood flow
C.Changes in perfusion pressure evoke changes in vascular resistance maintaining constant blood flow
189
39.Which of the following conditions would result to an increase in heart rate?
A.Expiration
B.Hypoxemia with mild increase in respiration
C.Increasing arterial pressure
D.Infusing blood or saline
D.Infusing blood or saline
190
40.Which of the following components is expected to decrease when administering a positive inotropic agent?
A.Stroke volume
B.End-systolic volume
C.Cardiac output
D.Heart rate
B.End-systolic volume
191
41.Which of the following parameters is NOT expected during moderate exercise?
A.Increase in pulse pressure
B.Increase in heart rate
C.Increase in cardiac output
D.Increase in total peripheral resistance
D.Increase in total peripheral resistance
192
42.Which of the following conditions would favour edema formation?
A.Enhanced muscular activity
B.Vasoconstriction of the arterioles
C.Rise in the venous pressure
D.Increase in the plasma protein concentration
C.Rise in the venous pressure
193
43. Which of the following would cause a downward shift in the cardiac function curve?
A.Giving intravenous saline
B.Giving vasoconstrictors
C.Giving negative inotropes
Giving positive chronotropes
C.Giving negative inotropes
194
44. Which of the following factors caused the upward shift in the cardiac function curve?
A.Increased total peripheral resistance (TPR)
B.Increased blood volume
C.Increased mean systemic filling pressure
D.Increased contractility
D.Increased contractility
195
45. Which of the following effects are derived from the cardiac function curve?
A.Decrease in stroke volume alone
B.Increase in both stroke volume and cardiac output
C.Increase in cardiac output alone
D.Decrease in both stroke volume and cardiac output
B.Increase in both stroke volume and cardiac output
196
46. Which of the following statements can be derived from the cardiac and vascular function curve?
A. Decreased cardiac output in the new state
B. Decreased venous return in the new state
C. Increased myocardial contractility
D. Increased mean systemic filling pressure
D. Increased mean systemic filling pressure
197
47. Which of the following factors caused the change in the cardiac and vascular function curve depicted by the dashed line?
A. Increase in blood volume
B. Increase in myocardial contractility
C. Increase in venomotor tone
D. Increase in cardiac output
A. Increase in blood volume
198
48.Which of the following effects is NOT seen in the cardiac and vascular function curve?
A.Increased myocardial contractility
B.Increased cardiac output
C.Increased venous return
D.Increased mean systemic filling pressure
A.Increased myocardial contractility
199
49.A 30-year old woman went for consult due to severe diarrhea. Her blood pressure then was 90/60 mmHg with her heart rate at 100beats/min. When she stood up the doctors noted her heart rate increased to 120 beats/min.
A.Decrease in total peripheral resistance
B.Decrease in venous return
C.Increase in contractility
D.Increase in venoconstriction
B.Decrease in venous return
200
50.A 30-year old woman went for consult due to severe diarrhea. Her blood pressure then was 90/60 mmHg with her heart rate at 100 beats per minute. When she stood up the doctors noted heart rate increased to 120 beats/min. After standing up, she felt dizzy and light-headed. Which of the following would explain the patient’s symptoms?
A.Increase in contractility, increased heart rate, increased cardiac output
B.Increase in venoconstriction, increased total peripheral resistance, increased arterial pressure
C.Decrease in total peripheral resistance, increased heart rate, increased cardiac output
D.Decrease in venous return, decreased preload, decreased cardiac output
D.Decrease in venous return, decreased preload, decreased cardiac output
