Toxic Responses of the Heart and Vascular System

Question 1

In Which of the following locations would one NOT find spontaneous depolarization?

a. SA node
b. myocardium
c. AV node
d. bundle of HIS
e. Purkinje fibers

Answer 1

b. myocardium

Question 2

Which one of the following scenarios would increase contractility of the myocardium?

a. increased activity of the Na+/K+-ATPase
b. increased activity of the sarcoplasmic reticulum Ca2+ ATPase
c. decreased activity of sarcoplasmic reticulum Ca2+ ATPase
d. decreased intracellular calcium levels
e. increased intracellular K+ levels

Answer 2

b. increased activity of the sarcoplasmic reticulum Ca2+ ATPase

Question 3

All of the following statements regarding abnormal cardiac function are true EXCEPT:

a. Ventricular arrhythmias are generally more severe than atrial arrhythmias
b. Ventricular hypertrophy is a common cause of ventricular arrhythmias
c. Coronary atherosclerosis is a major cause of ischemic heart disease
d. Right-sided heart failure results in pulmonary edema
e. Tachycardia is classified as a rapid resting heart rate (>100 beats/min)

Answer 3

d. Right-sided heart failure results in pulmonary edema

Question 4

Ion balance is very important in maintaining a normal cardiac rhythm. Which of the following statements is TRUE?

a. Blockade of K+ channels decreased the duration of the action potential
b. Blockade of Ca2+ channels has a positive ionotropic effect.
c. Inhibition of Na+ channels increases conductivity
d. Blockage if the Na+/K+-ATPase increases contractility
e. Calcium is transported into the cell via a Ca2+-ATPase

Answer 4

d. Blockage if the Na+/K+-ATPase increases contractility

Question 5

Which of the following is most likely NOT a cause of myocardial reperfusion injury?

a. cellular pH fluctuations
b. damage to the sarcolemma
c. generation of toxic oxygen radicals.
d. Ca2+ overload
e. inhibition of the electron transport chain

Answer 5

e. inhibition of the electron transport chain

Question 6

Which of the following statements regarding the cardiotoxic manifestations of ethanol consumption is FALSE?

a. Acute ethanol toxicity causes decreased conductivity
b. Chronic alcohol consumption is associated with arrhythmias
c. Acute ethanol toxicity causes an increased threshold for ventricular fibrillation
d. Chronic ethanol toxicity can result in cardiomyopathy
e. Acetaldehyde is a mediator of cardiotoxicity

Answer 6

c. Acute ethanol toxicity causes an increased threshold for ventricular fibrillation

Question 7

Cardiac glycosides:

a. increase the activity of the Na+/K+-ATPase
b. Make the resting membrane potential more negative
c. can have sympathomimetic and parasympathomimetic effects.
d. decrease ventricular contractility
e. increase AV conduction

Answer 7

c. can have sympathomimetic and parasympathomimetic effects.

Question 8

Which of the following is NOT a common cardiotoxic manifestation of cocaine abuse?

a. parasympathomimetic effects
b. myocardial infarction
c. cardiac myocyte death
d. ventricular fibrillation
e. ischemia

Answer 8

a. parasympathomimetic effects

Question 9

Using high doses of anabolic-androgenic steroids is NOT likely associated with which of the following?

a. an increase in LDL
b. cardiac hypertrophy
c. myocardial infarction
d. increased nitric oxide synthase expression
e. a decrease in HDL

Answer 9

d. increased nitric oxide synthase expression

Question 10

Which of the following is NOT a common mechanism of vascular toxicity?

a. membrane disruption
b. oxidative stress
c. bioactivation of protoxicants
d. reduction and accumulation of LDL in endothelium
e. accumulation of toxin in vascular cells

Answer 10

d. reduction and accumulation of LDL in endothelium