Question 1

Adrenergic antagonists that are selective for the beta-1 subtype (i.e.,beta-1 blockers)can be useful in the treatment of&#10;A) high blood pressure&#10;B) heart failure&#10;C) certain cardiac arrhythmias&#10;D) recovery from myocardial infarction&#10;E) all the above are true

Accepted Answer

Beta-1 blockers are useful in the treatment of high blood pressure, heart failure, certain cardiac arrhythmias, and recovery from myocardial infarction. They block the effects of epinephrine and norepinephrine on beta-1 receptors in the heart, which reduces heart rate and contractility, and blood pressure. This helps reduce the workload on the heart and improve its functioning. Thus, all the above options are true.

Question 2

To increase cardiac output,a drug should selectively _____ receptors on the heart.&#10;A) stimulate; alpha-1&#10;B) inhibit; alpha-1&#10;C) stimulate; alpha-2&#10;D) inhibit; alpha-2&#10;E) stimulate; beta-1

Accepted Answer

Stimulation of beta-1 receptors on the heart increases cardiac output by increasing heart rate and contractility. This is the mechanism of action of drugs like dobutamine, which are used to increase cardiac output in situations like heart failure or shock. Selective stimulation of alpha-1 or alpha-2 receptors may also increase cardiac output by increasing peripheral resistance, but this is not the most direct or effective way to increase cardiac output. Inhibition of alpha-1 or alpha-2 receptors is unlikely to increase cardiac output.

Question 3

A drug that selectively stimulates alpha-1 adrenergic receptors will cause&#10;A) vasoconstriction of peripheral arterioles&#10;B) increased heart rate&#10;C) decreased blood pressure&#10;D) bronchodilation

Accepted Answer

Activation of alpha-1 adrenergic receptors causes vasoconstriction of peripheral arterioles, which increases blood pressure. It does not affect heart rate or bronchodilation.

Question 4

Stimulation of alpha-2 adrenergic receptors on spinal interneurons typically results in a _______ in excitability of ______ supplied by these interneurons.&#10;A) increase; motor neurons&#10;B) decrease; motor neurons&#10;C) increase; sensory&#10;D) decrease; sensory&#10;E) alpha-2 receptors are not located in the spinal cord

Accepted Answer

Stimulation of alpha-2 adrenergic receptors on spinal interneurons typically results in a decrease in excitability of motor neurons supplied by these interneurons.

Question 5

Bronchospasm associated with respiratory ailments such as asthma,bronchitis,and emphysema is often treated with&#10;A) beta-1 adrenergic agonists&#10;B) beta-1 adrenergic antagonists (blockers)&#10;C) beta-2 adrenergic agonists&#10;D) beta-2 adrenergic antagonists (blockers)&#10;E) alpha-1 adrenergic agonists

Accepted Answer

Bronchospasm associated with respiratory ailments such as asthma, bronchitis, and emphysema is often treated with beta-2 adrenergic agonists. These drugs work by relaxing the smooth muscle in the airways, which opens them up and decreases the symptoms of bronchospasm. Beta-1 adrenergic agonists (A) and antagonists (B) are not effective for treating bronchospasm as they do not act on the smooth muscle in the airways. Similarly, beta-2 adrenergic antagonists (D) can actually worsen bronchospasm by blocking the relaxing effects of beta-2 agonists. Alpha-1 adrenergic agonists (E) are not typically used to treat bronchospasm associated with respiratory ailments.

Deck 20: Adrenergic Drugs