Neurons

Question 1

What are the two types of cells in the nervous system?

Answer 1

Neurons and glia

Neurons communicate information; glia provide support and nutrients.

Question 2

What is the primary function of neurons?

Answer 2

To communicate information within the nervous system

Neurons facilitate signaling between different parts of the nervous system.

Question 3

What are the functions of glia?

Answer 3

Providing structural support, insulation, and nutrients to neurons

Glia are essential for maintaining neuronal health and function.

Question 4

What are the main components of a neuron?

Answer 4

Dendrites, soma (cell body), and axon

Each component plays a critical role in the neuron’s function.

Question 5

What role do dendrites play in a neuron?

Answer 5

They receive information from other cells

Dendrites are the input sites for neuronal communication.

Question 6

What does the soma of a neuron contain?

Answer 6

Nucleus, mitochondria, ribosomes, and other essential elements

The soma is crucial for the cell’s survival and metabolic functions.

Question 7

What is the function of the axon in a neuron?

Answer 7

To transmit information to other cells

The axon is the output structure of a neuron, sending signals away from the cell body.

Question 8

What is myelin and its role in neurons?

Answer 8

A substance that insulates axons and speeds up information conduction

Myelin is produced by glia and is crucial for efficient signal transmission.

Question 9

Fill in the blank: Neurons vary in size and shape, but all have one or more _______.

Answer 9

dendrites

Dendrites are essential for receiving signals from other neurons.

Question 10

True or False: All axons are insulated with myelin.

Answer 10

False

Only some axons are insulated with myelin, which enhances conduction speed.

Question 12

What are the two processes involved in the communication of information in the nervous system?

Answer 12

Conduction within neurons and transmission between neurons

Question 13

What type of process is conduction of information within neurons?

Answer 13

An electrochemical process

Question 14

What happens when a neuron’s dendrites receive sufficient stimulation?

Answer 14

Channels in the cell membrane open, allowing positively charged sodium ions to enter the cell

Question 15

What is the resting state of a neuron characterized by?

Answer 15

The fluid inside the cell is negatively charged relative to fluid outside the cell

Question 16

What triggers depolarization in a neuron?

Answer 16

Sufficient stimulation

Question 17

What is an action potential?

Answer 17

An electrical impulse triggered by complete depolarization

Question 18

What does it mean that action potentials are all-or-none responses?

Answer 18

They either occur or don’t occur and have the same intensity when they do occur

Question 19

How is stimulus intensity encoded if not by the intensity of an action potential?

Answer 19

By the frequency of action potentials generated and/or by the number of neurons that generate action potentials

Question 20

Fill in the blank: A neuron returns to its _______ after an action potential occurs.

Answer 20

Resting state

Question 21

True or False: Action potentials vary in intensity based on the strength of the stimulus.

Answer 21

False

Question 22

What is the term for the transmission of information between neurons?

Answer 22

Synaptic transmission

Question 23

What type of transmission is usually involved in synaptic transmission?

Answer 23

Chemical

Question 24

What triggers the release of a neurotransmitter?

Answer 24

An action potential reaching the axon terminal

Question 25

What is the synaptic cleft?

Answer 25

The space between the axon terminal of the presynaptic neuron and the dendrite of an adjacent postsynaptic neuron

Question 26

Neurotransmitters can have what types of effects?

Answer 26

Excitatory or inhibitory

Question 27

What does an excitatory neurotransmitter do?

Answer 27

Increases the likelihood that an action potential will occur in a postsynaptic neuron

Question 28

What does an inhibitory neurotransmitter do?

Answer 28

Decreases the likelihood that an action potential will occur in a postsynaptic neuron

Question 29

What happens to a neurotransmitter after it has had its effect on a postsynaptic neuron?

Answer 29

It is inactivated

Question 30

How can a neurotransmitter be inactivated?

Answer 30

By being absorbed by the presynaptic neuron or being broken down by an enzyme

Question 31

What is neuroplasticity?

Answer 31

Neuroplasticity refers to the brain’s ability to modify, change, and adapt both structure and function throughout life and in response to experience. ## Footnote Also known as brain plasticity.

Question 32

What are the four types of neuroplasticity identified by Grafman?

Answer 32

* Homologous area adaptation * Cross-modal reassignment * Map expansion * Compensatory masquerade ## Footnote Each type has distinct mechanisms and implications for brain function.

Question 33

What occurs during homologous area adaptation?

Answer 33

Functions of a damaged brain area shift to the corresponding area in the opposite hemisphere. ## Footnote This adaptation can negatively affect pre-existing functions in the corresponding area.

Question 34

Give an example of homologous area adaptation.

Answer 34

Damage to the right parietal lobe in childhood may lead to the left parietal lobe taking over its visuospatial functions, impairing mathematical functions. ## Footnote This illustrates the trade-off involved in neuroplasticity.

Question 35

What is cross-modal reassignment?

Answer 35

A brain area responsible for a particular sensory input changes function when deprived of that input. ## Footnote This can lead to neurons processing different types of sensory information.

Question 36

Provide an example of cross-modal reassignment.

Answer 36

Neurons in the visual cortex of a child born blind may process somatosensory input instead of visual input. ## Footnote This allows the child to create cognitive representations of the physical world.

Question 37

What is map expansion?

Answer 37

The temporary or permanent enlargement of a functioning cortical region as a result of practice or exercise. ## Footnote Often occurs when learning a new skill.

Question 38

How does map expansion occur?

Answer 38

By recruiting neurons from the borders of the functioning cortical region. ## Footnote Example: Learning to play a musical instrument.

Question 39

What is compensatory masquerade?

Answer 39

Using alternative cognitive processes mediated by an intact area of the brain when usual processes are impaired. ## Footnote This occurs after damage to specific brain areas.

Question 40

Give an example of compensatory masquerade.

Answer 40

A person who loses their spatial sense due to brain injury may rely on memorizing landmarks to navigate. ## Footnote This demonstrates the brain's adaptability in response to injury.