L9: Cardiovascular Pharmacology

Question 1

*Phase 2 of the ventricular action potential is mediated by…

a. The inactivation of Na+ channels
b. An inward Na+ current and an outward K+ current
c. An inward Ca2+ current and an outward Na+ current
d. An inward Ca2+ current and an outward K+ current
e. Rapid activation of Na+ channels

Answer 1

d. An inward Ca2+ current and an outward K+ current

Question 2

*A Calcium channel blocker will NOT

a. Decrease cardiac contractility
b. Decrease the slope of Phase 4 in the SA node action potential
c. Shorten the duration of the ventricle action potential
d. Effect Phase 0 of the ventricular action potential
e. Be useful in treating arrhythmias

Answer 2

d. Effect Phase 0 of the ventricular action potential

Question 3

*Which of the following statements is TRUE

a. The renal system is unrelated to the etiology (underlying cause) of hypertension
b. Congestive heart failure is easily treated with pharmacological intervention
c. Angina is characterized by chest pain associated with an insufficient oxygen supply to cardiac tissue
d. All of these are true
e. None of these are true

Answer 3

c. Angina is characterized by chest pain associated with an insufficient oxygen supply to cardiac tissue

Question 4

*Which of the following statements is FALSE

a. Prostaglandin, specifically PG12, induces vasoconstriction
b. Nitric oxide promotes vasorelaxation
c. Activation of alpha1 adrenergic receptors leads to vasoconstriction
d. Angiotensin type 2 receptor activation promotes vasorelaxation

Answer 4

a. Prostaglandin, specifically PG12, induces vasoconstriction

Question 5

Phase 3 of the sinoatrial (SA) node action potential is mediated by ….

A. an inward K current

B. the inactivation of Ca2+ and Na+ channels and the activation of an outward K+ current

C. the inactivation of Ca2+ and Na+ channels and the activation of an inward K+ current

D. activation of the funny Na+ current

E. an inward Ca2+ current

Answer 5

B. the inactivation of Ca2+ and Na+ channels and the activation of an outward K+ current

Question 6

An alpha1 antagonist would …

A. cause arterial smooth muscle relaxation

B. be useful for treating hypertension

C. have its actions potentiated by a beta2 agonist

D. not increase cardiac smooth muscle contraction and heart rate

E. All of the above

Answer 6

E. All of the above

Question 7

Basal levels of renin can be elevated in a patient with hypertension. Which of the following drug combination can reduce the effects of renin…

A. ACE inhibitors and Ca 2+ channel blockers

B. ACE and AT1 receptor inhibitors

C. AT1 receptor inhibitors and beta-blockers

D. beta-blockers and Ca2+ channel blockers

E. muscarinic acetylcholine receptor agonist and Na+ channel blocker:

Answer 7

B. ACE and AT1 receptor inhibitors

Question 8

Potential side effects of diuretics include:

A. Electrolyte imbalance such as hypokalemia (low blood potassium)

B. Increased oxygen demand of the heart

c. reduced blood volume

D. Both a and b

E. Both a and c

Answer 8

E. Both a and c

Question 9

All of the following are involved in phase 3 of the SA node action potential EXCEPT

a. Gradual depolarization
b. Inactivation of Ca 2+ channels
c. Inactivation of Na + channels
d. Activation of K+ channels
e. All of the above are involved

Answer 9

a. Gradual depolarization

Question 10

Relaxation of cardiac muscle occurs when calcium is removed by

a. Being pumped into the sarcoplasmic reticulum by the SER Calcium ATPase
b. Being pumped out of the cell via the Na + /Ca 2+ exchanger
c. Reuptake into the mitochondria via ryanodine receptors
d. Both A and B
e. All of the above

Answer 10

d. Both A and B

Question 11

All of the following will occur if you block alpha1 receptors except:

a. Contractility decreases
b. Vasorelaxation
c. HR decreases
d. BP decreases

Answer 11

a. Contractility decreases

Question 12

Juxtaglomerular cells, also called granular cells, monitor blood pressure and secrete renin in response to

a. Decrease arterial blood pressure
b. Decreased levels of NaCl in the distal tubule
c. Increased SNS activity
d. Signals received by macula densa cells
e. All of the above

Answer 12

e. All of the above

Question 13

These receptors (2) mediate vascular smooth muscle contraction by enhancing Ca2+ influx

Answer 13

Alpha1 Receptors and Angiotensin 1 Receptor

Question 14

Name three conditions that stimulate renin secretion

Answer 14

1) Decreased arterial BP
2) Decreased NaCl in the distal tubule
3) SNS Activity

Question 15

How will a Ca2+ channel blocker affect cardiac contractility?

Answer 15

↑ Concentration = ↓ Contractility

Question 16

What happens when you:

• *1) Partially block Na+ channels
  2) Completely block Na+ channels
  3) Block K+ channels**

Answer 16

• *1) Partially block Na+ channels**
• Prevent depolarization, increasing the duration between action potentials
• *2) Completely block Na+ channels**
• Prevent all action potentials
• *3) Block K+ channels**
• Prevent repolarization, prolonging action potential

Question 17

What will happen to the ventricular action potential in the presence of a Ca2+ channel antagonist?

Answer 17

↓ duration

Question 18

What will happen to the SA node action potential in the presence of a Ca2+ channel antagonist?

Answer 18

↓ amplitude
↓ slope of the slow depolarization