ajkim1's version from 2015-05-30 01:25


Question Answer
Cardiac output from the left side of the heart is _____ blood flowSystemic
Cardiac output from the right side of the heart is _____ blood flowPulmonary
Blood volume contained in the arteries is called _____ _____Stressed volume
Site of highest resistance in the CV systemArterioles
Where A1-adrenergic receptors are foundArterioles of skin, splanchnic, and renal circulations
Where B2-adrenergic receptors are foundArterioles of skeletal muscles
Largest total cross-sectional and surface area of CV systemCapillaries
Site of highest proportion of blood in the CV systemVeins
Blood volume contained in the veins is called _____Unstressed volume
Equation for velocity of blood flowv=Q/A
Velocity is _____ proportional to blood flow and _____ proportional to the cross-sectional area at any level of the CV systemDirectly; Inversely
Equation for blood flowQ=[delta(P)]/R
Poiseuille's equation of resistanceR=(8nl)/(pi*r^4)
_____ _____ predicts whether blood flow will be laminar or turbulentReynold's number
Increased Reynold's number indicates _____Turbulence
Shear is _____ at the wall, where the difference in blood velocity is _____ and _____ at the center of the vessel, where blood velocity is _____Highest; greatest; lowest; constant
Equation for capacitanceC=V/P
Highest arterial pressure during a cardiac cycleSystolic pressure
Lowest arterial pressure during a cardiac cycleDiastolic pressure
Most important determinant of pulse pressureStroke volume
Mean arterial pressureDiastolic pressure + 1/3(pulse pressure)


Question Answer
P waveAtrial depolarization
PR intervalInitial depolarization of ventricle
PR interval varies with _____Conduction velocity through AV node
If AV nodal conduction decreases (heart block), the PR interval _____Increases
PR interval _____ by stimulation of sympathetic nervous systemDecreases
PR interval _____ by stimulation of parasympathetic nervous systemIncreases
QRS complexDepolarization of ventricles
QT intervalEntire period of depolarization and depolarization of ventricles
ST segmentVentricles are depolarized
T waveVentricular repolarization
Resting membrane potential is determined by _____Conductance to K+
Role of Na+, K+, ATPaseMaintain ionic gradients across cell membranes


Question Answer
Stable resting membrane potential of ventricles, atria, and Purkinje system-90 mV
Phase 0Upstroke of the AP
Phase 0 has increased _____ conductance which results in an inward _____ current that depolarizes the membraneNa+
Phase 1Brief period of initial repolarization
Phase 1's has outward current because of the movement of _____ ions out of the cell and a _____ in Na+ conductance
Question Answer
Phase 2Plateau of the AP
Phase 2 has a transient increase in _____ conductance, which results in an inward _____ current and an increase in _____ conductanceCa2+; Ca2+; K+
Phase 3Repolarization
Phase 3 has _____ conductance decrease and _____ conductance increaseCa2+; K+
Phase 4Resting membrane potential
Phase 4 is the period in which inward and outward currents are equal and the membrane potential approaches the _____ equilibrium potentialK+


Question Answer
SA nodePacemaker of the heart
Resting potential of SA nodeUnstable
Latent pacemakers that may exhibit automaticity and override the SA node if suppressedAV node and His-Purkinje systems
Exhibits phase 4 depolarization or automaticitySA node
Intrinsic rate of phase 4 depolarization from fastest to slowestSA node, AV node, His-Purkinje
Phase 0Upstroke of AP
Phase 0 is caused by increase in _____ conductance, which causes an inward _____ current that drives the membrane potential toward the _____ equilibrium potentialCa2+
Phases not present in the SA node AP1 and 2
Phase 3Repolarization
Phase 3 is caused by increase in _____ conductance, which causes an outward _____ current that causes depolarization of the membrane potentialK+
Phase 4Slow depolarization
Accounts for pacemaker activity of the SA node (automaticity)Phase 4
Phase 4 is caused by an increase in _____ conductance, which results in an inward _____ currentNa+
IfInward Na+ current
If is turned on byDepolarization of the membrane potential during the preceding AP


Question Answer
Upstroke of the AP in the AV node is the result of an inward _____ currentCa+
Conduction velocity is fastest in the _____Purkinje system
Conduction velocity is slowest in the _____AV node
Refractory periodsChanges in excitability over the course of the AP
Absolute refractory periodTime during which no AP can be initiated
Effective refractory periodTime during which conducted AP cannot be elicited
Relative refractory periodTime during which an AP can be elicited, but more than the usual inward current is required
Negative chronotropic effectDecreases HR by decreasing firing rate of SA node
Positive chronotropic effectIncreases HR by increasing firing rate of SA node
Negative dromotropic effectDecreases conduction velocity through AV node, slowing conduction of APs from atria to ventricles and increasing PR interval
Positive dromotopic effectIncreases conduction velocity through AV node, speeding conduction of APs from atria to ventricles and decreasing PR interval
Neurotransmitter at B1 receptorsNorepinephrine


Question Answer
SarcomereContractile unit of the myocardial cell
Intercalated disksOccurs at the ends of the cells, maintains cell-to-cell cohesion
_____ are more numerous in cardiac muscle than in skeletal muscleMitochondria
Well-developed in the ventricles but poorly developed in the atriaT-tubules
Site of storage and release of Ca2+ for excitation-contraction coupling
Question Answer
Contractility is related to _____Intracellular Ca2+ concentration
Contractility can be measured by _____Ejection fraction (0.55 or 55%)
Pre-loadEnd-diastolic volume, which is related to right atrial pressure
Afterload for left ventricleAortic pressure
After load for right ventriclePulmonary artery pressure
Velocity of contraction at a fixed muscle length is _____ when the after load is zero and is _____ by increases in afterloadMaximal; decreased
Frank-Starling relationshipDescribes increases in stroke volume and CO that occur in response to an increase in venous return or end-diastolic volume
_____ contractility causes an increase in CO for any level of right atrial pressure or end-diastolic volumeIncreased
_____ contractility causes a decrease in CO for any level of right atrial pressure or end-diastolic volumeDecreased
Increased preloadIncrease in end-diastolic volume and is the result of increased venous return; increase in stroke volume
Increased afterloadDecrease in stroke volume; increase in end-systolic volume
Positive inotropic agentsIncreased contractility and increased CO
Negative inotropic agentsDecreased contractility and decreased CO
Stroke volumeVolume ejected from the ventricle on each beat
Equation for stroke volumeEnd-diastolic volume - end-systolic volume
Equation for COCO= stroke volume x HR
Ejection fractionFraction of the end-diastolic volume ejected in each stroke volume
Stroke workWork the heart performs on each beat