Pharmacodynamics: Major Receptor Families Quiz

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What term is used to describe the actions of a drug on the body and the influence of drug concentrations on the magnitude of the response?

  • Pharmacogenetics
  • Pharmacokinetics
  • Pharmacodynamics (correct)
  • Pharmacotherapy

In pharmacodynamics, what type of molecules are part of the cascade of events translating agonist binding into a cellular response?

  • Enzymes
  • Antibodies
  • Second messenger or effector molecules (correct)
  • Hormones

What is a drug termed when it binds to a site on a receptor protein and activates it to initiate a series of reactions?

  • Inhibitor
  • Stimulant
  • Antagonist
  • Agonist (correct)

Which type of receptors in cardiac cells bind and respond to acetylcholine?

<p>Muscarinic receptors (D)</p> Signup and view all the answers

What happens when the nicotinic receptor is stimulated by acetylcholine?

<p>Sodium influx and potassium outflux (B)</p> Signup and view all the answers

How do local anesthetics affect the voltage-gated sodium channel?

<p>Inhibit sodium influx (B)</p> Signup and view all the answers

What type of receptors increase chloride influx and hyperpolarization of neurons upon agonist stimulation?

<p>GABA receptors (B)</p> Signup and view all the answers

Which major biological process involves the transcription of DNA into RNA and translation of RNA into proteins?

<p>Protein synthesis (B)</p> Signup and view all the answers

How do ligand-gated ion channels typically behave before being activated by an agonist?

<p>They are closed (A)</p> Signup and view all the answers

What is the typical time course for the activation and response of receptors mentioned in the text?

<p>Hours to days (D)</p> Signup and view all the answers

Which type of receptors exert their action on target cells via intracellular receptors?

<p>G protein-linked receptors (A)</p> Signup and view all the answers

What is a characteristic feature of G protein-linked and enzyme-linked receptors in signal transduction?

<p>Ability to amplify signal intensity and duration (C)</p> Signup and view all the answers

What is the purpose of determining the Therapeutic Index (TI) of a drug?

<p>To establish the effective and toxic dose ranges of the drug (A)</p> Signup and view all the answers

Why are some drugs with low Therapeutic Indices still used to treat serious diseases?

<p>Because the risk of untreated disease outweighs the risk of adverse effects (A)</p> Signup and view all the answers

What happens to patients as the dose of warfarin is gradually increased?

<p>A greater fraction of patients respond as desired until all patients respond (C)</p> Signup and view all the answers

Why is bioavailability critical for drugs with low Therapeutic Indices?

<p>Because it can alter the therapeutic effects significantly (C)</p> Signup and view all the answers

What is the role of the α subunit of a G protein in transmembrane G Protein–Coupled Receptors?

<p>Binds guanosine triphosphate (GTP) (C)</p> Signup and view all the answers

What is the main effect of an agonist binding to a transmembrane G Protein–Coupled Receptor?

<p>Increases GTP binding to the α subunit (D)</p> Signup and view all the answers

Which cellular effector is commonly activated by Gs and inhibited by Gi in transmembrane G Protein–Coupled Receptors?

<p>Adenylyl cyclase (A)</p> Signup and view all the answers

What is the function of the β and γ subunits of a G protein in transmembrane G Protein–Coupled Receptors?

<p>Anchors the G protein in the cell membrane (C)</p> Signup and view all the answers

Which feature characterizes the activation and response of intracellular receptors, such as steroid hormones, as mentioned in the text?

<p>A time course on the order of hours to days (A)</p> Signup and view all the answers

What is potency in the context of pharmacology?

<p>The amount of drug necessary to produce an effect (B)</p> Signup and view all the answers

What is the main target of antimicrobials like trimethoprim, as discussed in the text?

<p>Enzymes (B)</p> Signup and view all the answers

How is potency typically determined in pharmacology?

<p>By using the concentration of drug producing 50% of the maximum effect (A)</p> Signup and view all the answers

Which characteristic of signal transduction is prominent in G protein-linked and enzyme-linked receptors according to the text?

<p>Amplification of signal intensity and duration (B)</p> Signup and view all the answers

What does a Graded Dose-Response Curve show in pharmacology?

<p>The gradual increase in pharmacologic effect with increasing drug concentration (B)</p> Signup and view all the answers

What is a notable mechanism of signal transduction described in the text that protects cells from excessive stimulation?

<p>Signal termination (D)</p> Signup and view all the answers

How does the EC50 for Drugs A and B indicate potency?

<p>Drug A requires less drug to reach 50% effect than Drug B (B)</p> Signup and view all the answers

What term is used to describe the relationship between the dose of a drug and the proportion of a population that responds to it?

<p>Quantal dose-response curve (B)</p> Signup and view all the answers

In pharmacodynamics, what does the Therapeutic Index (TI) of a drug indicate?

<p>The safety of the drug (A)</p> Signup and view all the answers

What does ED50 represent in a quantal dose-response curve?

<p>Drug dose causing a therapeutic response in half the population (A)</p> Signup and view all the answers

How is the therapeutic index (TI) calculated for a drug?

<p>TD50 / ED50 (A)</p> Signup and view all the answers

Transmembrane G Protein-Coupled Receptors consist of two protein subunits in the G protein.

<p>False (B)</p> Signup and view all the answers

Binding of an agonist to the receptor decreases GTP binding to the α subunit.

<p>False (B)</p> Signup and view all the answers

The activated effectors produced by Gs and inhibited by Gi generally involve DNA transcription within the cell.

<p>False (B)</p> Signup and view all the answers

Adenylyl cyclase produces the second messenger cyclic adenosine monophosphate (cAMP) upon activation by Gi.

<p>False (B)</p> Signup and view all the answers

Ligand-gated ion channels primarily contain the ligand binding site in the intracellular portion.

<p>False (B)</p> Signup and view all the answers

Membrane-bound proteins are not rich sources of receptors that transduce extracellular signals into intracellular responses.

<p>False (B)</p> Signup and view all the answers

Hydrophilic ligands interact with receptors on the cell surface, while hydrophobic ligands interact with intracellular receptors.

<p>True (A)</p> Signup and view all the answers

Enzymes, nucleic acids, and structural proteins cannot act as receptors for drugs or endogenous agonists.

<p>False (B)</p> Signup and view all the answers

In a quantal dose-response curve, a positive response is defined as a rise of at least 5 mm Hg in systolic blood pressure.

<p>False (B)</p> Signup and view all the answers

Quantal dose-response curves have different shapes compared to log dose-response curves.

<p>False (B)</p> Signup and view all the answers

A drug's Therapeutic Index (TI) is calculated as the ratio of the dose that produces toxicity in half the population (TD50) to the dose that produces a clinically desired response in half the population (ED50).

<p>True (A)</p> Signup and view all the answers

The Therapeutic Index (TI) indicates a drug's efficacy by showing how well it binds to its target receptor.

<p>False (B)</p> Signup and view all the answers

Warfarin is an example of a drug with a large therapeutic index.

<p>False (B)</p> Signup and view all the answers

All patients respond to warfarin at higher doses with no risk of hemorrhage.

<p>False (B)</p> Signup and view all the answers

Bioavailability does not critically alter the therapeutic effects of drugs with low therapeutic indices.

<p>False (B)</p> Signup and view all the answers

The desired response to warfarin is a decrease in the international normalized ratio (INR).

<p>False (B)</p> Signup and view all the answers

Potency is a measure of the drug concentration that produces 100% of the maximum effect.

<p>False (B)</p> Signup and view all the answers

The EC50 value indicates that Drug A is less potent than Drug B.

<p>False (B)</p> Signup and view all the answers

Graded dose-response curves cannot determine drug efficacy and potency.

<p>False (B)</p> Signup and view all the answers

Therapeutic preparations of drugs always reflect their efficacy rather than their potency.

<p>False (B)</p> Signup and view all the answers

Ligand-gated ion channels always contain the ligand binding site in the extracellular portion.

<p>False (B)</p> Signup and view all the answers

G protein–coupled receptors consist of two protein subunits in the G protein.

<p>False (B)</p> Signup and view all the answers

Activation of transmembrane ligand-gated ion channels by an agonist leads to sodium outflux and potassium influx.

<p>False (B)</p> Signup and view all the answers

Local anesthetics bind to the voltage-gated sodium channel, promoting sodium influx and increasing neuronal conduction.

<p>False (B)</p> Signup and view all the answers

Partial agonists like aripiprazole have the ability to stimulate dopaminergic pathways that are overactive.

<p>False (B)</p> Signup and view all the answers

Inverse agonists stabilize the active conformation of receptors when interacting with an agonist.

<p>False (B)</p> Signup and view all the answers

Antagonists can increase the effect of an agonist when present.

<p>False (B)</p> Signup and view all the answers

Inverse agonists have an intrinsic activity greater than zero.

<p>False (B)</p> Signup and view all the answers

In a quantal dose-response curve, a positive response is defined as a rise of at least 5 mm Hg in systolic blood pressure.

<p>False (B)</p> Signup and view all the answers

Adenylyl cyclase produces the second messenger cyclic adenosine monophosphate (cAMP) upon activation by Gi.

<p>False (B)</p> Signup and view all the answers

Quantal dose-response curves have different shapes compared to log dose-response curves.

<p>False (B)</p> Signup and view all the answers

All patients respond to warfarin at higher doses with no risk of hemorrhage.

<p>False (B)</p> Signup and view all the answers

Flashcards are hidden until you start studying

Related Documents

Pharmacodynamics PDF

More Like This

Use Quizgecko on...
Browser
Browser