B4M2Q1 18-19 Flashcards
During the Physiology Laboratory, Peter was tasked to expose the heart of the frog.
He was asked by his professor to locate the SA node. Which would best describe
the location of the SA node?
A. It is located in the posterior wall of the right atrium, behind the tricuspid valve
B. It is located in the superior posterolateral wall of the right atrium, immediately
below and slightly lateral to the opening of the superior vena cava
C. It is located in the inferior anterolateral wall of the right atrium, immediately
behind the tricuspid valve
D. It is located in the posterior wall just behind the opening of the superior vena
cava
B. It is located in the superior posterolateral wall of the right atrium, immediately
below and slightly lateral to the opening of the superior vena cava
Which of the secondary pacemakers of the heart would have a discharge rate of
40-60/ min?
A. Penetrating portions of AV bundle
B. Purkinje fibers
C. AV node
D. Atria
C. AV node
How much time is the delay in the AV node itself before an impulse enters the
penetrating portion of the AV bundle
A. 0.03 sec
B. 0.06 sec
C. 0.09 sec
D. 012 sec
C. 0.09 sec
If you were on duty, where would you place the chest lead to measure V1?
A. 4th ICS, left sternal border
B. 4th ICS, right sternal border
C. 5th ICS, right midclavicular line
D. 5th ICS, left midclavicular line
B. 4th ICS, right sternal border
Where would you position your unipolar limb lead to measure the aVL?
A. Right arm
B. Left arm
C. Right leg
D. Left leg
B. Left arm
Liza was experiencing Angina pectoris upon going up a flight of 5 stairs. She was
brought to your clinic for evaluation. Which test would you do to get a graphic
recording of the electric potential generated by the heart?
A. 3D Echogram
B. CT-scan
C. Doppler ultrasonography
D. Electrocardiogram
D. Electrocardiogram
Tricia, a 30 year old, BPO employee had her ECG taken and she brought to you her
tracings. Which represents depolarization of the atrial muscle in the ECG
tracings?
A. P wave
B. T wave
C. PR interval
D. QT interval
A. P wave
The deflection of the QRS complex is biphasic in which lead?
A. V3
B. V4
C. V5
D. V6
A. V3
The deflection of the QRS complex is negative in which lead/leads?
A. AVL, V4 to V6
B. AVR, V1 to V2
C. AVF, V4 to V6
D. AVL, AVF and AVR
B. AVR, V1 to V2
Given that there are 25 small squares between 2 consecutive QRS complexes, what
is the heart rate if the 1500 method is used?
A. 100 bpm
B. 80 bpm
C. 60 bpm
D. 40 bpm
C. 60 bpm
If you place your stethoscope on the second right interspace what valve are you
auscultating?
A. Pulmonic
B. Tricuspid
C. Aortic
D. Mitral
C. Aortic
Sounds from the pulmonic valve are best heard at the:
A. first and second interspaces close to the sternum
B. fourth interspace midclavicular
C. second and third interspace close to the sternum
D. fifth interspace
C. second and third interspace close to the sternum
Which of the following is supplied by the left coronary artery?
A. All of the right ventricle
B. Diaphragmatic surface of the left ventricle
C. Posterior inferior third of the ventricular septum
D. Right bundle branch
D. Right bundle branch
What valve guards the opening of the coronary sinus?
A. Eustachian
B. Thebesian
C. Mitral
D. Aortic
B. Thebesian
Where do the cardiac muscles attach to?
A. Cardiac jelly
B. Fibrous pericardium
C. Cardiac skeleton
D. Purkinje fibers
C. Cardiac skeleton
An embolus found in the left pulmonary artery most probably came from the:
A. Left coronary artery
B. Left atrium
C. Right ventricle
D. Right coronary artery
C. Right ventricle
Where does the coronary sinus open into?
A. Right atrium
B. Left atrium
C. Right ventricle
D. Left ventricle
A. Right atrium
From what nerve does the parasympathetic supply of the heart come from?
A. Phrenic
B. Vagus
C. Splanchnic
D. Coronary
B. Vagus
Activation of the postganglionic sympathetic fibers supplying the heart would result
to:
A. cardiac deceleration
B. decreased force of myocardial contraction
C. decreased ventricular contractions
D. dilatation of coronary arteries
D. dilatation of coronary arteries
A chondroid tissue that serves as central support of the heart and for attachment of
muscles is the:
A. subendocardial layer
B. cardiac skeleton
C. Purkinje fibers
D. fibrous pericardium
B. cardiac skeleton
Which of the following depolarizes the membrane to threshold?
A. Inward current
B. Outward current
C. Subthreshold inward current
D. Subthreshold outward current
A. Inward current
Which of the following describes slow response action potential?
A. Na channels open
B. Na channels abruptly close
C. Ca-Na channels remain open
D.K channels open
C. Ca-Na channels remain open
Which of the following determines the resting membrane potential?
A.K ions
B. Na ions
C.Ca ions
D. Mg ions
A.K ions
Which of the (5) phases in the ventricle, atria, purkinje system action potential
corresponds to the resting membrane potential?
A. Phase 1
B. Phase 2
C. Phase 3
D. Phase 4
D. Phase 4
What is the K+ equilibrium potential?
A. +120 mV
B. -90 mV
C. +65 mV
D. -85 mV
D. -85 mV
Which of the following has the fastest intrinsic rate of depolarization?
A. Purkinje fibers
B.AV node
C.SA node
D. bundle of His
C.SA node
Which of the following accounts for the pacemaker activity of the SA node?
A. Inward Na current
B. Inward Ca current
C. Outward K current
D. Outward Ca current
A. Inward Na current
Which of the following causes rapid depolarization phase of the atrial, ventricular
and Purkinje fibers?
A. Na current
B.K current
C.Ca current
D. pacemaker current
A. Na current
Which of the following is true for relative refractory period?
A. Membrane cannot be reexcited by outside stimulus
B. Only a local response can be produced
C. Propagated action potential cannot be generated
D. Stronger than normal stimulus cause excitation
D. Stronger than normal stimulus cause excitation
What is the role of Na-K-ATPase?
A. Brings positive charge into the cell
B. Takes positive charge out of the cell
C. Maintains ion gradients across the cell membrane
D. Establishes diffusion potentials of permeant ions
C. Maintains ion gradients across the cell membrane
Conduction tissues of the heart where the transmission of impulses from the atria
to the ventricle is delayed.
A. SA node
B. AV node
C. AV bundle
D. Purkinje fibers
B. AV node
Conduction of impulses in the AV bundle is extremely slow due to-
A. absence of contractile elements in its fibers
B. diminish number of gap junction between the successive muscle cell
C. allows only forward conduction from the atria to the ventricle and vice versa
D. it’s very large fibers than the ventricular muscle
B. diminish number of gap junction between the successive muscle cell
Stimulation of the vagus nerves can cause which of the following?
A. Decrease the rate of rhythm of the SA node
B. Shortens the AV nodal conduction time
C. Increase the force of contraction of the heart
D. Increase the level of excitability of the heart
A. Decrease the rate of rhythm of the SA node
Which of the following ions is responsible for the action potential of the SA and
AV node?
A. Na+
B. K+
C. Ca++
D. Mg++
C. Ca++
The arrow in the ECG tracing in Figure 1 represents what waveform?
Figure 1:
A. P wave
B. QRS complex
C. Q wave
D. T wave
D. T wave
The arrow in Figure 1 represents which phase of the cardiac action potential?
A. Atrial depolarization
B. Atrial repolarization
C. Ventricular repolarization
D. Ventricular depolarization
C. Ventricular repolarization
The shaded portion in the ECG tracing in Figure 2 represents what? Figure 2:
A. P wave
B. PR interval
C. PR segment
D. P-P interval
B. PR interval
The shaded portion of the ECG tracing in Figure 2 may become abnormal in which
of the following conditions?
A. Ventricular hypertrophy
B. Ventricular infarction
C. Ventricular ischemia
D. AV conduction blocks
D. AV conduction blocks
Which of the following statements concerning the delay of transmission of cardiac
impulses from the atria into the ventricular is true?
A. This is caused to a very high level of permeability of the gap junction
B. Prevents re-entry of cardiac impulses back to the atria
C. This allow time for the atria to empty their blood into the ventricles before
ventricular contraction.
D. This is due to unstable membrane potential
C. This allow time for the atria to empty their blood into the ventricles before
The fibers of this specialized conducting tissues have almost no contractile
filaments:
A. Purkinje fibers
B. AV node
C. AV bundle
D. SA node
D. SA node
In utero, the heart begins to beat when the fetus is:
A. 10-12 days
B. 22-23 days
C. 25-28 days
D. 32-35 days
B. 22-23 days
The only adult derivative of the posterior cardinal veins:
A. Common iliac vein
B. Gonadal vein
C. Superior vena cava
D. aortic arch
A. Common iliac vein
The base of the heart is attached to:
A. Bronchi
B. Descending aorta
C. Fibrous pericardium
D. Central tendon
D. Central tendon
The apex of the heart is formed by:
A. Right ventricle
B. Left ventricle
C. Right and left ventricle
D. Right atrium and left ventricle
B. Left ventricle
The superior border of the heart is formed by:
A. Left ventricle
B. Left costal cartilage
C. Third right costal cartilage
D. Roots of the great blood vessels
D. Roots of the great blood vessels
Which of the following atrioventricular openings has no valve?
A. Superior vena cava
B. Coronary sinus
C. Aortic orifice
D. Right atrioventricular opening
A. Superior vena cava
A shallow depression which is the remnast of the foramen ovale located on the atrial
septum.
A. Musculi pectinati
B. Oblique sinus
C. Fossa ovalis
D. Sulcus terminalis
C. Fossa ovalis
Which of the following statements concerning the left ventricle is true?
A. Has lesser trabeculae carneae
B. Three times thicker than the right ventricle
C. Has 4 openings for pulomonary veins
D. has 5 large papillary muscle
B. Three times thicker than the right ventricle
The right atrioventricular opening is guarded by:
A. Mitral valve
B. Thebesian valve
C. Tricuspid valve
D. Eustachian valve
C. Tricuspid valve
Location of the pericardium:
A. Located at the roots of the great vessels
B. Lie within the middle mediastinum
C. Lie opposite the apex of the heart
D. Lie at the level of the fifth left intercostal space
B. Lie within the middle mediastinum
