PHYSIO-LEC-LE-3-Feed-2022 (1) Flashcards
- The greatest blood volume
A. Arteries
B. Arterioles
C. Capillaries
D. Veins
D. Veins
- Capillaries are ideal for the exchange of substances because they have:
✔ Large cross sectional area
- Slow response action potential is present in one of these:
A. Atrial myocytes
B. Bundle of his
C. Purkinje fibers
D. SA node
D. SA node
- Conduction is more likely to be_____ due to its slow response action potential that causes response due to _____ of action potential (question unclear).
✔ Slow Amplitude
- Phase 0 of cardiac action potential is due to:
A. Ca++ influx
B. Ca++ efflux
C. K+ efflux
D. Na+ influx
A. Ca++ influx
- During phase 4 of an action potential, this occurs.
✔ Sodium enters cell through 3 sodium 1 Calcium antiporter
- Depolarization of slow response action potential is due to
✔ Lets Calcium influx through Calcium channels
- Effect of acetylcholine to myocardial
A. Decrease in Ca channels
B. Decrease in K channels
C. Increase in Ca conductance
D. Increase in Na Funny channels
A. Decrease in Ca channels
- Importance of effective refractory period
✔ Prevents cardiac muscle to produce new AP
- Conduction velocity increases when there is
✔ Increase the rate of depolarization
- Effect of more negative action potential in conduction velocity is
✔ Increase conduction due to larger amplitude of an action potential
- Ionic currents involve slow response depolarization occurs outward
✔ Calcium influx and potassium efflux, potassium currents depolarizes cell
- Heart rate decreases when there is
✔ Increase negativity in the pressure potential
- Heart rate decreases when there is
✔ Increase negativity in the pressure potential
- Mechanism for overdrive suppression is:
A. Activation of cell’s intrinsic automaticity
B. Depolarization of cardiac cell with Na+ influx
C. Hyperpolarization of cell with Na+ efflux
D. Suppression of NaKATPase
C. Hyperpolarization of cell with Na+ efflux
- Importance of conduction delay in AV node is:
✔ Allow sufficient ventricular filling.
- Significance of long refractory period of Purkinje fibers is to:
A. Prevent premature contraction of atria
B. Prevent premature contraction of ventricle
C. Promote premature contraction of atria
D. Promote premature contraction of ventricle
B. Prevent premature contraction of ventricle
- This phenomenon is responsible for the initiation of impulses through the SA node as the pacemaker
A. Absolute Refractory Period
B. Overdrive Suppression
C. Post-repolarization refractories
D. Depolarization of diastole
B. Overdrive Suppression
- The major factor responsible for contractile stage of myocardium is:
A. Free intracellular Ca++
B. K+ gradient across membrane
C. Na+ gradient across membrane
D. Sarcoplasmic Ca++ concentration
A. Free intracellular Ca++
- What occurs during myocardial contraction?
✔ Entry of calcium through calcium channels
- Cardiac glycosides increase cardiac contractile force through
✔ Increase in intracellular sodium decrease in calcium (…)
- Catecholamines have one of these effects on excitation-contraction coupling
✔ Inhibit binding of calcium by troponin C
- Increased Preload
A. Decrease BP
B. Decrease Myocardial Contraction Force
C. Increase Afterload
D. Increase Stroke Volume
D. Increase Stroke Volume
- Frank-Starling mechanism is responsible for one of this:
✔ Increased stroke volume when ventricular diastolic volume is increased
- The constant preload an increase in afterload results in
✔ Increase systolic pressure
- Positive inotropy in the heart will increase
✔ Cardiac output
- The ratio of volume ejected from LV per beat (Stroke Volume) to volume of blood in LV (EDV)
A. Blood Pressure
B. Cardiac Output
C. Ejection Fraction
D. Pulse Pressure
C. Ejection Fraction
- The cardiac valves are physiologically important because
✔ Ensure unidirectional flow of blood
- Closure of the aortic valve is best heard at the
✔ Second intercostal space right sternal boarder
- The physiologic splitting of the second heart sound is the closure of the
✔ Pulmonic valve
- R wave of the electrocardiogram coincides with one of the stages in the cardiac cycle
✔ Isovolemic contraction
- S2 is heard during what phase
A. Isovolumic contraction
B. Isovolumic relaxation
C. Rapid ejection
D. Rapid filling
D. Rapid filling
- Phase between the closing of mitral valve and opening of aortic valve
A. Isovolumic relaxation
B. Isovolumic contraction
C. Rapid filling
D. Rapid ejection
B. Isovolumic contraction
- One of these proceeds rapid phase in the cardiac cycle
✔ Opening of the aortic valve
- According to Poiseuilles Law if blood flow is increased:
✔ Radius also increases
- The most important factor that changes blood vessel diameter
✔ Smooth muscle contraction
- The 12 lead ECG is useful for the diagnosis of all of these except:
✔ Congestive heart failure
- QT interval of ECG represents:
A. Atrial Depolarization
B. Atrial Systole
C. Ventricular Depolarization
D. Ventricular Systole
D. Ventricular Systole
- What represent atrial depolarization
✔ P wave
- Cardiac axis of ECG of -180 degrees signifies the presence of
✔ Right axis deviation
- Mechanism of sinus tachycardia is increased
✔ Rate of depolarization
- The most important factor that affects muscular resistance is
✔ Radius of the vessel
- Turbulent flow occurs when there is DECREASED:
A. Blood Viscosity
B. Flow Velocity
C. Fluid Density
D. Vessel Diameter
A. Blood Viscosity
- Blood pressure increases when there is
✔ Increase peripheral vascular resistance and cardiac output
- What is the effect of flow stroke volume on BP decreases due to
✔ Decrease in cardiac output
- Arterial pulse pressure increases when there is decrease
✔ Arterial compliance
- All of these can prevent venous pooling towards the legs except:
✔ Prolonged Standing
- Critical (…) in pressure increases when there is
✔ Inhibition of sympathetic stimulates the parasympathetic nervous system
- One of these is associated with edema:
✔ Low serum albumin and low plasma oncotic pressure
- Rate of fluid movement into capillary walls decreases when there is an increase in
✔ Distance across capillary wall
- Lymphatics are important because they
✔ Return flow rates in the vascular spaces
- Lymph will increase in following
A. Low hydrostatic pressure
B. High plasma oncotic pressure
C. High interstitial oncotic pressure
D. High interstitial hydrostatic pressure
B. High plasma oncotic pressure
- Which of these factors decrease coronary blood flow
✔ Extravascular compression of the coronary vessels
- What Main function of cutaneous circulation?
✔ To maintain body temperature
- Metabolic factor predominant in control of ______ circulation
A. Cerebral
B. Fetal
C. Hepatic
D. Resting muscle
???
- One of these is characteristic feature of fetal circulation
✔ Ductus arteriosus connects pulmonary artery and the aorta
- Which of these circulatory changes during birth?
✔ High arterial oxygen initiates closure of the ductus arteriosus
- PNS is responsible for beat to beat control of SA node because it has
A. Gradual onset of action
B. Long latency
C. Rapid decay of response
D. All of the above
???
- A reflex that decreases the heart rate when the blood pressure increases.
✔ Baroreceptor
- Mechanism for sinus tachycardia is that heart rate
✔ Is that heart rate increases during inspiration and decreases during expiration
✔ Heart rate increases due to increased venous return
- Which if this is responsible for intrinsic regulation of myocardial performance
✔ Frank starling mechanism
- Effect of increase ventricular volume on myocardial performance
✔ Increase sensitivity of the cardiac myofilaments to calcium
- The effect of increased heart rate of myocardial cell calcium is that
✔ Myocardial cell calcium increases due to increase (…)
- The effect of sympathetic stimulation on ventricular contractility
✔ Ventricular contractility increases with increase in ventricular filling
- Which of the following increase cardiac output by decreasing peripheral vascular resistance?
✔ Thyroid hormone
- When arterioles contract in response to increase perfussion pressure is an example of ____ peripheral regulation conduction
A. Endothelium mediated
B. Frank-starling mechanism
C. Metabolic mechanism
D. Myocardial mechanism
D. Myocardial mechanism
- One of these is the effect of stimulation of pressor area of dorsal lateral medulla
A. + inotropy, chronotropy, vasodilation
B. + inotropy, chronotropy, vasoconstriction
C. - inotropy, chronotropy, vasodilation
D. - inotropy, chronotropy, vasoconstriction
B. + inotropy, chronotropy, vasoconstriction
- Vascular response to high pressure is to: A. Peripheral vasoconstriction due to inhibition of sympathetic outflow
B. Peripheral vasoconstriction due to stimulation of sympathetic outflow
C. Peripheral vasodilation due to inhibition of sympathetic outflow
D. Peripheral vasodilation due to stimulation of sympathetic outflow
C. Peripheral vasodilation due to inhibition of sympathetic outflow
- Feature of baroreceptors
A. Sensitive to changes in BP
B. Sensitive to changes in Blood Volume
C. reactive to (…)
D. reactive to small (…)
A. Sensitive to changes in BP
- Stimulation of peripheral chemoreceptors will cause
A. Vasoconstriction Low BP
B. Vasoconstriction High BP
C. Vasodilation High BP
D. Vasodilation Low BP
B. Vasoconstriction High BP
- Characteristic feature of factors affecting vascular calcium currents increase in
✔ Peripheral resistance decreases central venous pressure
- Compared to cardiac function curve, vascular function curve is one of this features
✔ Central venous pressure depends on cardiac valve
- Cardiac output decreases when there is an increase in
A. Blood volume
B. Myocardial contractility
C. Peripheral vascular resistance
D. Preload
C. Peripheral vascular resistance
- Mechanism of reduction of cardiac output in Muller’s maneuver
✔ Increase venous return due to the collapse in the extra thoracic veins
- The effect of Valsalva’s maneuver on blood pressure is that
✔ Blood pressure decreases due to decrease in venous return
- Cardiovascular adjustment during exercise includes
A. Decrease blood flow to the brain
B. Decrease heart rate
C. Increase CO
D. Increase Vagal Stimulation
C. Increase CO
- Post exercise recovery is characterized of which of the following?
✔ Decrease in peripheral vascular resistance due to vasodilator predominance
- Effect of physical exercise and conditioning of the circulatory system:
✔ Decrease peripheral vascular resistance.
- Compensatory mechanism to hypotension during hemorrhage includes
✔ Increase myocardial contractile force
- Effect of cranial ischemia to hypovolemic shock:
✔ Increase sympathetic tone
- Mechanism for heart failure during hypovolemic shock, Decrease in
✔ Ventricular function due to decrease coronary protrusion
- Acidosis during hypo..
✔ Impaired in (…) will increase Hydrogen ions
- The effect of blood loss on cardiovascular system is
✔ To decrease preload due to increase stroke volume
- Which of these cardiovascular responses in hemorrhage will (…) severity of blood loss
✔ Heart rate
- Major compensatory mechanism to restore intravascular volume during hemorrhage?
✔ Trancapillary Refill
- Mechanism for failure of vasoconstrictor response during hemorrhagic shock includes
✔ Depletion of neurotransmitter to vasoconstrict
- Which of these occurs during transcapilllary refill
✔ Capillary hydrostatic pressure increases
- One of these promoted blood flow upward during erect posture:
✔ Muscle contraction and venous valves
- Fight or flight response include:
✔ High cardiac output
- Fight or flight reaction includes
A. High CO
B. Low BP
C. Slow HR
D. Venous dilatation
A. High CO
- The major cardiovascular response to exercise is
✔ Increase cardiac output
- Progressive prolongation PR interval followed by a drop beat
✔ Decremental conduction
- One of these is disorder of impulse formation abnormal automaticity
✔ AV Junctional tachycardia
- Which of these affects impulse conduction?
A. Membrane potential at the end of repolarization
B. Rate of depolarization
C. Slope of phase 4
D. Threshold potential
B. Rate of depolarization
