A Certain Drug Decreases Heart Rate by Blocking a Receptor

question 5

Multiple Choice

A certain drug decreases heart rate by blocking a receptor on cardiac pacemaker cells. This drug probably binds to ________ receptors.

• A) nicotinic cholinergic
• B) muscarinic cholinergic
• C) alpha-1 adrenergic
• D) alpha-2 adrenergic
• E) beta-1 adrenergic

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Definitions:

Exposure

refers to the extent or duration to which an individual is subjected to a particular environment, substance, or condition.

Testing Effect

A threat to internal validity in which taking a pretest changes behavior without any effect on the independent variable.

Quasi-experimental Designs

Research designs that attempt to establish causal relationships but lack random assignment of participants to conditions.

Cholesterol Level

A measurement of the total cholesterol, including low-density and high-density lipoprotein, in an individual's blood.