Question 1

Which of the following best describes the difference between electrical and chemical signals in neural communication?

Accepted Answer

Electrical signals involve changes in membrane potential, while chemical signals involve the release of molecules such as neurotransmitters.

Question 2

Which of the following is NOT a form of local communication in the body?

Accepted Answer

Hormones

Question 3

In signal transduction, which of the following correctly identifies the first messenger and the second messenger?

Accepted Answer

First messenger: extracellular signal molecule; Second messenger: intracellular signaling molecule

Question 4

Which type of gated channel opens in response to a change in membrane potential?

Accepted Answer

Voltage-gated channel

Question 5

A drug that binds to a receptor and activates it, mimicking the effect of the natural ligand, is called:

Accepted Answer

Agonist

Question 6

Which control system typically has the fastest response time and highest specificity?

Accepted Answer

Neural system

Question 7

How is stimulus intensity coded in neurons?

Accepted Answer

By the frequency of action potentials

Question 8

Which of the following is a correct description of the two divisions of the peripheral nervous system (PNS)?

Accepted Answer

Somatic and autonomic divisions

Question 9

Which part of the neuron typically receives incoming signals?

Accepted Answer

Dendrite

Question 10

Which type of glial cell is responsible for myelinating axons in the central nervous system?

Accepted Answer

Oligodendrocyte

Question 11

What is the primary function of the Nodes of Ranvier?

Accepted Answer

To facilitate saltatory conduction of action potentials

Question 12

On which side of the neuronal cell membrane is the concentration of $$\mathrm{K^+}$$ ions higher?

Accepted Answer

Inside the cell

Question 13

Where do graded potentials typically occur in a neuron?

Accepted Answer

At the dendrites and cell body

Question 14

Which statement best describes the 'all-or-none' property of action potentials?

Accepted Answer

Action potentials only occur if the membrane potential reaches threshold; otherwise, they do not occur at all.

Question 15

A patient is diagnosed with multiple sclerosis, a disease that damages myelin in the CNS. Which cell type is primarily affected?

Accepted Answer

Oligodendrocytes

Question 16

Which of the following best explains why action potentials do not decrease in strength as they travel along the axon?

Accepted Answer

Action potentials are regenerated at each segment of the axon due to voltage-gated $$\mathrm{Na^+}$$ and $$\mathrm{K^+}$$ channels.

Question 17

Which of the following is a function of microglia in the nervous system?

Accepted Answer

Providing immune defense and removing debris

Question 18

If a neurotransmitter acts as an antagonist, what is its effect on the receptor?

Accepted Answer

It blocks the receptor, preventing activation by the natural ligand.

Question 19

Which of the following best describes myelination?

Accepted Answer

The addition of a fatty sheath around axons to increase the speed of electrical conduction

Question 20

A neuron receives multiple subthreshold graded potentials at its dendrites. What is the likely outcome at the axon hillock?

Accepted Answer

No action potential will be generated unless the graded potentials summate to reach threshold.

Study Guide: Neural Communication and the Nervous System (Chapters 6 & 8)

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