Question 1

Which of the following best describes a neurohormone?

Accepted Answer

A chemical messenger produced by neurons and released into the blood via interstitial fluid.

Question 2

Which of the following is an example of a neurohormone?

Accepted Answer

Antidiuretic hormone (ADH)

Question 3

What determines the location of receptors for a chemical messenger on a target cell?

Accepted Answer

The chemical property of the messenger (lipophilic or lipophobic)

Question 4

Lipophobic messengers typically bind to receptors located:

Accepted Answer

On the plasma membrane

Question 5

Which of the following is a correct pairing of messenger type and receptor location?

Accepted Answer

Lipophilic messenger — cytosol or nucleus

Question 6

A patient is given a drug that blocks channel-linked receptors. Which type of messenger would be most affected?

Accepted Answer

Lipophobic messengers

Question 7

Which of the following best explains why lipophilic messengers can activate gene transcription?

Accepted Answer

They diffuse through the plasma membrane and bind to intracellular receptors.

Question 8

Which equation best represents the specificity of messenger-receptor binding?

Accepted Answer

$$K_d = \frac{[R][M]}{[RM]}$$

Question 9

A mutation causes a target cell to express only receptor B. Which messenger will this cell respond to?

Accepted Answer

Only the messenger specific to receptor B

Question 10

Which of the following is NOT a functional class of chemical messenger listed in the study materials?

Accepted Answer

Enzymes

Question 11

Which of the following scenarios best illustrates paracrine signaling?

Accepted Answer

A cell releases a messenger that acts on neighboring cells in the same tissue.

Question 12

Which type of receptor is most likely to be involved in rapid changes in membrane potential?

Accepted Answer

Channel-linked receptor

Question 13

Which of the following is TRUE regarding the difference between nervous and endocrine communication?

Accepted Answer

Nervous communication is rapid and targeted, while endocrine communication is slower and affects distant targets.

Question 14

Which class of neuron carries information from the periphery to the central nervous system?

Accepted Answer

Afferent neurons

Question 15

A scientist discovers a new messenger that is lipophobic and acts as a neurotransmitter. Where are its receptors most likely located?

Accepted Answer

On the plasma membrane of the target cell

Question 16

Which of the following best describes the role of interneurons?

Accepted Answer

They connect afferent and efferent neurons within the CNS.

Question 17

Which of the following is a correct sequence for information flow in the nervous system?

Accepted Answer

Afferent neuron → Interneuron → Efferent neuron

Question 18

Which of the following is most likely to result from activation of a G-protein-linked receptor?

Accepted Answer

Activation of intracellular second messengers

Question 19

A hormone binds to a receptor in the cytosol and initiates gene activation. Which chemical property does this hormone most likely possess?

Accepted Answer

Lipophilic

Question 20

Which of the following best explains why lipophobic messengers require membrane-bound receptors?

Accepted Answer

They are unable to diffuse through the lipid bilayer of the plasma membrane.

Cell Communication: Chemical Messengers, Receptors, and Signal Transduction

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