Exam 1 Flashcards
Inflammatory pathways promote thrombosis, which is responsible for myocardial infarction and most strokes?
True or False
True
Ischemia is most responsible
What is released from the endothelial wall, that promotes vasodilation and limits platelet extension? A. thromboxane A2 B. prostaglandin F 2 a C. prostacyclin (PGI2) D. norepinephrine
C. prostacyclin (PGI2)
Thromboxane A2 vasoconstricts and produced by platelets
A traumatized vessel will constrict; most of the constriction is due to which of the following?
A. SNS reflex contraction
B. thromboxane A2 release from platelets
C. local myogenic spasm
D. prostacyclin release from the endothelium
C. local myogenic spasm
Which of the following is effective at dissolving blood clots? A. plasmin B. throboxane A2 C. prostacyclin D. heparin
A. plasmin
Heparin prevents clots from forming
What is the key step in blood coagulation?
A. release of platelet granule contents
B. activation of factors X and V
C. sympathetic stimulation of vascular smooth muscle
D. conversion of fibrinogen to fibrin
D. conversion of fibrinogen to fibrin
requires thrombin
Fibrinogen and prothrombin along with factors VII, IX, X are produced by which organ? A. liver B. lungs C. spleen D. kidney
A. Liver
Concerning Ca++ role in blood clotting, which of the following statements is true?
A. required at all intrinsic pathway steps
B. only required at all extrinsic pathway steps
C. required at all steps except the 1st two intrinsic steps
D. required only to allow thrombin to convert fibrinogen to fibrin
C. required at all steps except the 1st two intrinsic steps
required at all extrinsic steps
Compared to a typical ventricular muscle cell, which of the following is a characteristic of the SA node?
A. only fast Na+ channels operational
B. longer plateau
C. lacks a stable resting polarized state
D. more negative resting membrane potential
C. lacks a stable resting polarized state
SA node leaks ions
AV delayed wave and SA fastest
At a normal resting membrane potential of -85 mV, which of the following ions is closest to its Nernst equilibrium potential? A. Na+ B. Ca++ C. K+ D. Cl-
C. K+
A 2-3 X elevation in extracellular fluid of what ion can cause flaccidity and weakness of cardiac muscle in part by decreasing the resting membrane potential A. Na+ B. Ca++ C. K+ D. Cl-
C. K+
If end diastolic volume = 160 ml and end systolic volume = 120 ml; what is the ejection fraction? A. 25% B. 50% C. 75% D. undeterminable
A. 25%
100 X 40/160 = 25%
normal = 50%-60%
The aortic valve opens at what point? (on graph drawing) A. A B. B C. C D. D
B. B
The mitral valve opens at what point? (on graph drawing) A. A B. B C. C D. D
D. D
Emptying of the ventricle occurs between what two letters? (on heart drawing) A. AB B. BC C. CD D. DA
C. CD
Isovolumic relaxation occurs between what two letters? (on heart drawing) A. AB B. BC C. CD D. DA
D. DA
What percentage of blood from the atrial to the ventricle is actively pumped? A. 25%-30% B. 45%-55% C. 70%-75% D. 95%-100%
A. 25%-30%
70%-75% passive
Norepinephrine binds to which cardiac receptors? A. alpha B. beta C. muscarinic D. nicotinic
B. beta
At rest, if you block both divisions of the autonomic nervous system, which of the following changes would occur?
A. both HR and strength of contraction will decrease
B. both HR and strength of contraction will increase
C. HR will increase and strength of contraction will decrease
D. HR will decrease and strength of contraction will increase
C. HR will increase and strength of contraction will decrease
What allows the action potential to spread from one cardiac cell to an adjacent cardiac cell, and therefore allows the heart to behave as a syncytium? A. purkinje system B. intercalated discs C. type C nerve fibers D. AV node
B. intercalated discs
Which of the following create only a diastolic murmur? A. aortic stenosis B. pulmonic stenosis C. mitral stenosis D. patent ductus arteriosis
C. mitral stenosis
aortic and pulmonic stenosis = systole murmur
Reperfusion injury following infarction is primarily associated with which of the following? A. overdrive suppression B. arrhythmias C. sympathetic activity D. free radical production
D. free radical production
If the left atrial pressure is 7mmHg, the left ventricular pressure is 100 mmHg, and the aortic blood pressure is 106 mmHg, what is the status of the valves on that side of the heart?
A. mitral and aortic valves closed
B. mitral valve closed and aortic valve open
C. mitral valve open and aortic valve closed
D. mitral and aortic valves open
A. mitral and aortic valves closed
Increased stretch on the ventricular fibers during filling, have what effect on calcium influx into the ventricular cells?
A. increase
B. decrease
C. no effect
A. increase
Which of the following has a positive inotropic effect on the ventricle? A. acetylcholine B. thyroxine C. atrial natriurectic peptide D. alcohol
B. thyroxine
A wave of repolarization moving toward the positive recording electrode would create what type of deflection?
A. positive deflection
B. negative deflection
C. no appreciable deflection
B. negative deflection
When does myocardial blood flow peak in the left ventricle? A. at the onset of diastole B. mid systole C. at the onset of systole D. mid diastole
A. at the onset of diastole
right ventricle - mid systole
On the following EKG, what can you say about the circled area?
A. the wave of depolarization is moving toward the positive electrode
B. the wave of depolarization is moving toward the negative electrode
C. the wave of repolarization is moving toward the positive electrode
D. the wave of repolarization is moving toward the negative electrode
A. red
B. black
D. green
Which of the following statements regarding a prolonged QT interval (increased incidence of sudden cardiac death) is true?
A. females are more susceptible
B. males are more susceptible than females
C. children are more susceptible than adults
D. adults are more susceptible than children
B. males are more susceptible than females
If the sympathetic nerves to the heart are cut, and then the SNS is stimulated, heart rate will still increase, why?
A. intrinsic autoregulation will compensate
B. due to local release of sympathetic neuropeptides
C. circulating norepinephrine/epinephrine from the adrenal medulla
D. adrenergic parasympathetic innervation dominates
C. circulating norepinephrine/epinephrine from the adrenal medulla
Under resting conditions, what percentage of oxygen is extracted by the myocardium from the perfusing coronary blood flow? A. 20% B. 50% C. 70% D. 90%
C. 70%
The preferred energy substrate of ventricular cardiac cells is which of the following? A. amino acid B. glucose C. pyruvate D. fatty acids
D. fatty acids
At a constant operating pressure what happens to the wall tension as the radius of that chamber decreases?
A. increases
B. decreases
C. stays constant
B. decreases
No consistent relationship of P waves to QRS complexes describes which of the following? A. 1st degree AV block B. 2nd degree AV block C. 3rd degree AV block D. bundle branch block
C. 3rd degree AV block
If you block fast Na+ channels in a typical cardiac muscle cell using “tetradotoxin”, what will be observed?
A. the cell is unable to depolarize
B. depolarization is slowed
C. the cell will die
D. the cell will depolarize, but is unable to contract
B. depolarization is slowed
What quadrant is the mean electrical axis in?
(electrical circle graph)
A. right axis deviation
B. left axis deviation
B. left axis deviation
As heart rate increases, cycle length decreases, which of the following statements is true?
A. systole and diastole both shorten by a equal amount
B. diastole shortens more than systole
C. systole shortens more than diastole
D. only diastole shortens, systole stays constant
B. diastole shortens more than systole
Most of the energy consumed by the heart for work is utilized for which of the following?
A. pressurization of blood by the ventricles
B. acceleration of blood out of the ventricles
C. closure of the valves
D. production of heat
A. pressurization of blood by the ventricles
production of heat is not work, 75% ends up as this
An inverted T wave is associated with which of the following? A. infarction B. left ventricular hypertrophy C. first degree AV block D. ischemia
D. ischemia
What is the major function of the AV node?
A. normal pacemaker of the heart
B. delays the wave of depolarization from the atria to the ventricle
C. rapidly transmits the wave of depolarization from the atria to the ventricle
D. allows the ventricle to depolarize as a unit
B. delays the wave of depolarization from the atria to the ventricle
Which of the following changes in ion influx will slow the heart rate? A. increase in Na+ influx B. increase in K+ efflux C. increase in Ca++ influx D. decrease in K+ efflux
B. increase in K+ efflux
A,C,D speed up heart rate
