Deck 10: Properties and Functions of Neuroglial Cells

Question 1

Which glial cells move to sites of injury in the brain?

A) Astrocytes
B) Schwann cells
C) Oligodendrocytes
D) Radial glial cells
E) Microglial cells

Answer 1

E

Question 2

Glial cells have been found to be the most common source of tumors in the brain. Why might this be?

A) Certain glial cells grow too large.
B) Certain glial cells can migrate throughout the CNS.
C) Certain glial cells are not susceptible to programmed cell death.
D) Certain glial cells can divide.
E) Certain glial cells mutate more easily.

Answer 2

D

Question 3

What is the primary role associated with oligodendrocytes?

A) They produce astrocytes in the adult CNS.
B) They regulate cerebrospinal fluid.
C) They form the myelin sheath around axons within the central nervous system.
D) They move to sites of injury within the brain.
E) They form the myelin sheath around axons within the peripheral nervous system.

Answer 3

C

Question 4

You are provided with a slide of cells taken from an adult CNS and must label which are neurons and which are glial cells. What is one way to tell them apart?

A) Glial cells have axons that are longer and wider than those of neurons.
B) Glial cells do not have axons.
C) Glial cells have axons that are longer and thinner than those of neurons.
D) Glial cells have axons, but not dendrites.
E) There are no "rule of thumb" ways to tell glial cells from neurons.

Question 5

Which type of glial cell myelinates axons in the peripheral nervous system?

A) Oligodendrocytes
B) Astrocytes
C) Radial glial cells
D) Microglial cells
E) Schwann cells

Question 6

Which statement about microglia is true?

A) They develop from the neural crest and are found in the central nervous system.
B) They develop from the neural crest and are found in the peripheral nervous system.
C) They develop from the mesoderm and are found in the central nervous system.
D) They develop from the mesoderm and are found in the peripheral nervous system.
E) They develop from the neural tube and are found in the central nervous system.

Question 7

_______ astrocytes are prevalent in the white matter of the brain, around myelinated nerve fibers, and _______ astrocytes are prevalent in the grey matter of the brain, around cell bodies and synapses.

A) Long; short
B) Microglial; Schwann
C) Radial; fibrous
D) Fibrous; protoplasmic
E) Protoplasmic; radial

Question 8

Which of the following is true about NG2 cells in the developing nervous system?

A) They are precursors to both astrocytes and radial glial cells.
B) They are precursors to both oligodendrocytes and astrocytes.
C) They cannot produce action potentials.
D) They are of mesodermal origin.
E) They are precursors to both oligodendrocytes and radial glial cells.

Question 9

Ependymal cells derive from which type of cell?

A) Radial glial cells
B) Schwann cells
C) Microglia
D) Astrocytes
E) NG2 cells

Question 10

Which of the following best describes the mechanism behind the increased oxygen detected by fMRI during brain activity?

A) Glial cells aid in increasing capillary blood flow through their interaction with neurons and capillaries during periods of high activation.
B) There is an increase in the flow of oxygen ions along the axons of active neurons.
C) Glial cells allow more molecules into the intracellular space during periods of high activation.
D) Glial cells transport oxygen and other ions/molecules from blood capillaries directly to neurons during periods of high activation.
E) Oxygen ion channels in glial cells near blood capillaries become more permeable during periods of high activation, allowing more oxygen ions into glial networks.

Question 11

Why might it be advantageous for glial cells to serve as a "buffer" between capillaries and neurons?

A) Glial cells can increase the speed of transfer of neurotransmitters to neurons.
B) Capillaries can easily burst, which could damage neurons.
C) Glial cells can help regulate blood flow in relation to neural activity.
D) Neurons can send neurotransmitters through capillaries to other neurons.
E) Capillaries contain toxins that can kill neurons through direct contact.

Question 12

One consequence of gap junction connections between glial cells is

A) faster transport of neurotransmitter molecules between glial cells.
B) lower intracellular concentrations of potassium, allowing for continuous reuptake of potassium.
C) higher intracellular concentrations of potassium, slowing down reuptake of potassium.
D) easier transfer of nutrients between glial cells.
E) higher concentration gradients between glial cells.

Question 13

High concentrations of water-conducting channels, AQP4, help some glial cells prevent shrinkage of extracellular space by transporting.

A) water from the extracellular space into the glial cells.
B) water from the glial cells into the extracellular space.
C) sodium between glial cells and the extracellular space.
D) water between glial cells and other glial cells.
E) sodium between glial cells.

Question 14

You are a graduate student conducting an experiment in which you are using an intracellular electrode to record the membrane potential of an optic neuron when exposed to a very brief (0.1 second) flash of light. To your surprise, the optic neuron's membrane potential is recording at -90 mV and there is a longer-than-expected delay between the flash of light and depolarization of the neuron. You report your findings to the lab PI, who responds,

A) "The organism likely has a mutation which causes their neurons to have lower resting potentials."
B) "You likely placed the electrode in an adjacent glial cell."
C) "The organism has improper myelination, resulting in a slower-than-normal response to light."
D) "Glial cells can cause neurons to have lower resting potentials; remove the glial cells and try again."
E) "You placed the electrode in the neuron's cell body instead of its axon."

Question 15

If a section of neural tissue was placed in a potassium bath, the glial cells would respond to the potassium by being

A) depolarized, and more depolarized than the neurons.
B) depolarized, but less depolarized than the neurons.
C) completely unaffected by external potassium.
D) hyperpolarized, and more hyperpolarized than the neurons.
E) hyperpolarized, but less hyperpolarized than the neurons.

Question 16

Which statement about glial communication is most true?

A) Glial cells and glial precursor cells cannot fire action potentials.
B) Only glial precursor cells can fire action potentials.
C) All glial cells and glial precursor cells can fire action potentials.
D) Only mature glial cells can fire action potentials.
E) Only astrocytes can fire action potentials.

Question 17

Depolarization of glial cells largely involves the transport of _______ ions across the cell membrane.

A) calcium
B) sodium
C) potassium
D) oxygen
E) chlorine

Question 18

Glial cells generally have different resting membrane potentials than neurons. What is one consequence of this?

A) Glial cells can continuously uptake potassium ions over a concentration gradient.
B) Glial cells can send faster signals to one another.
C) Glial cells can release more sodium ions to the extracellular space.
D) Glial cells can uptake more water from the extracellular space over a concentration gradient.
E) Glial cells can serve as effective insulators for axons.

Question 19

Greater depolarization of the end foot of certain glial cells in response to neuron stimulation suggests that there is a higher concentration of

A) AQP4 channels in the end foot.
B) of calcium channels in the end foot.
C) potassium ions in the end foot.
D) axons near the end foot.
E) potassium channels in the end foot.

Question 20

Certain glial cells can change shape when responding to an injury. How does changing from star-shaped, to globular, to round-shaped body help in this response?

A) It allows the glial cell to travel throughout the CNS.
B) It allows the glial cell to send signals to damaged neurons.
C) It allows the glial cell to replicate.
D) It allows the glial cell to engage in phagocytosis, clearing debris.
E) It allows the glial cell to form new myelin around damaged neurons.

Question 21

Glial cells responsible for responding to injury rely on the accumulation of which substance to spur their movement?

A) glutamate
B) potassium
C) ATP
D) calcium
E) adenosine

Question 22

Gaps in the myelin sheath around axons contribute to the increased velocity of conduction down axons because

A) the nodes contain higher concentrations of potassium pumps.
B) ions can only flow into the axon via these nodes.
C) the nodes are impermeable to ions.
D) microglial cells make contact with the axon at the nodes in the CNS.
E) water can flow into the axon via these nodes.

Question 23

Glial cells in the central nervous system can myelinate _______ section(s) of an axon; glial cells in the peripheral nervous system can myelinate _______ section(s) of an axon.

A) one; one
B) several; several
C) several; one
D) one; several
E) no; several f. several; no

Question 24

Some glial cells have been shown to be especially apt at myelination, even myelinating synthetic material. This fact suggests that

A) glial cells can myelinate any cell.
B) myelination must be inhibited to avoid over-myelination.
C) myelination is an efficient process.
D) glial cells must undergo cell death to avoid over-myelination.
E) new axons cannot be myelinated.

Question 25

Proper myelination of axons is crucial to prevent disorders. Therefore, an exact amount of a myelin protein, _______ is essential.

A) ATP
B) connexon
C) AQP4
D) PMP22
E) ACh

Question 26

Binding proteins that facilitate the cooperative creation of myelin sheaths and nodes of Ranvier are called

A) neurotransmitters.
B) potassium channels.
C) ankyrins.
D) neurotrophins.
E) connexons.

Question 27

You observe two groups of mice. One group exhibits normal behavior while the other group is clumsy and exhibits marked tremors or trembling. What is the most likely reason for the difference in behavior between the two groups of mice?

A) The trembling mice have fewer neurons than the normal mice.
B) The trembling mice have improper myelination compared to the normal mice.
C) The trembling mice have glial cells that are less connected to one another than the normal mice.
D) The trembling mice have more potassium channels in their glial cells than the normal mice.
E) The trembling mice have less microglial cells than the normal mice.

Question 28

Voltage recordings of glial cells during activation of nearby neurons show depolarization of the glia. This is due to

A) uptake of potassium from clefts.
B) movement of calcium through glial cell networks.
C) hyperpolarization of nearby neurons.
D) uptake of sodium from clefts.
E) release of potassium from the glial cell.

Question 29

Compared to neurons, glial cells that have become depolarized take a relatively long time to return to resting potential. What is one possible reason for this?

A) Glial cells are smaller than neurons and have fewer ion channels.
B) Glial cells have lower resting potentials than neurons.
C) Neurons are myelinated, which contributes to the speed of their return to resting potential.
D) Potassium spreads through networks of glial cells, which slows the return to resting potential.
E) Calcium waves through glial networks prevent potassium from reentering the glial cells.

Question 30

Waves of _______ ions can propagate through glial cell networks, triggering the release of _______ through channels along the glial cell membrane.

A) sodium; potassium
B) calcium; potassium
C) ATP; sodium
D) calcium; ATP
E) sodium; ATP

Question 31

Observing microglial cells in living tissue has revealed that these cells

A) are able to change structure to become more like oligodendrocytes.
B) extend fine processes throughout the environment and contact surrounding cells.
C) transport calcium ions to neurons.
D) are unchanging from the time an organism reaches adulthood.
E) are responsible for blood clotting in injured adult brains.

Question 32

Transmitters such as glutamate can be released by dying nerve cells in the brain due to injury, which depolarizes nearby glial cells. One consequence of this is glial cells

A) also release glutamate, exacerbating the effect of brain injury.
B) release calcium, exacerbating the effect of the brain injury.
C) release debris, increasing immune response in the brain.
D) fire action potentials, causing deleterious signaling through the brain region.
E) die, increasing the volume of the extracellular space.

Question 33

_______ have been shown to occupy denervated motor end plates, releasing packets of _______ to produce potentials in muscles.

A) Oligodendrocytes; potassium
B) Microglia; glutamate
C) Astrocytes; ATP
D) NG2 cells; calcium
E) Schwann cells; ACh

Question 34

Certain glial cells can release growth factors and neurotrophin-3, which have effects on the development of neurons. What does this fact suggest about glial cells?

A) They contribute to action potentials.
B) They contribute to neuroplasticity.
C) They contribute to CNS immune responses.
D) They contribute to synaptic pruning.
E) They contribute to clearing of debris.

Question 35

Glial cells are implicated in the reuptake of certain neurotransmitters. One of these is glutamate, an excess of which can activate certain receptors in neurons, leading to calcium entry and

A) over-myelination.
B) increased conduction velocity.
C) release of other neurotransmitters.
D) lower resting potential.
E) cell death.

Question 36

Glial cells may have immediate effects on synaptic transmission of neurons by

A) increasing the rate of neurotransmitter release.
B) bridging activity of neurons with other neurons.
C) decreasing the reuptake of certain neurotransmitters.
D) reducing the resting potential of neurons.
E) increasing flow of cerebrospinal fluid throughout the CNS.

Question 37

The choroid plexus is a group of specialized cells that are responsible for the production of

A) cerebrospinal fluid.
B) select neurotransmitters.
C) microglia cells.
D) myelin sheaths.
E) potassium pumps.

Question 38

The main purpose of the blood-brain barrier is to

A) stop the movement of certain molecules from the bloodstream into the brain.
B) protect the bloodstream from neuronal debris.
C) stop neurotransmitters from passing into the bloodstream.
D) prohibit the movement of any molecules from the bloodstream into the brain.
E) protect endothelial cells from damage caused by neuronal activity.

Question 39

Like immune cells, _______ have specialized receptors for _______.

A) astrocytes; cytokines
B) oligodendrocytes; adenosine
C) microglia; cytokines
D) astrocytes; glutamate
E) microglia; adenosine

Question 40

Certain glial cells can serve as an immune system for the brain. One way these cells can accomplish this is through their ability to

A) hyperpolarize other glial cells.
B) send action potentials.
C) release ATP.
D) communicate with other glial cells, neurons, and immune cells.
E) myelinate axons.

Question 41

Astrocytes placed in culture also containing T lymphocytes, a type of immune cell, have been shown to

A) attack T lymphocytes.
B) both stimulate and suppress activity of T lymphocytes.
C) only suppress activity of T lymphocytes.
D) only stimulate activity of T lymphocytes.
E) myelinate T lymphocytes.

Question 42

Typical neural development involves pruning of excess connections between neurons, but this process fails without the presence of immunological complement receptor 3 (CR3). Which type of glial cell expresses CR3?

A) Astrocytes
B) Microglia
C) Oligodendrocytes
D) Schwann cells
E) Radial glial cells

Question 43

First described as "nerve glue," glial cells have since been shown to be essential components of a functioning nervous system. Briefly describe at least two essential glial cell functions.

Question 44

Glial cells play important roles during the development of the adult nervous system. Describe one such glial cell and the part it plays in development.

Question 45

Describe at least two physical ways that neurons and glial cells can be contrasted.

Question 46

Name two types of glial cells found in the central nervous system and state their major functions.

Question 47

Evidence suggests that glia can be electrically coupled with neurons. Describe the nature of these electrical connections.

Question 48

Networks of glial cells are coupled by gap junctions between cell membranes. This has consequences on the behavior of the cell networks in terms of how they function within the nervous system. Describe one of these consequences.

Question 49

Describe which glial cells respond to lesions and how they assist with clearing the lesion site.

Question 50

Myelination of axons requires precise spacing of nodes, adequate seals between the myelin sheaths and axon, and proper distributions of sodium and potassium pumps at the nodes. Describe why such a delicate balance is necessary for an adequate increase in the velocity of conductance along the axon.

Question 51

Given the role that myelination plays, describe how the behavior of an organism with inadequate myelination might differ from one with proper myelination.

Question 52

Explain what spatial buffering is and state one reason this process is beneficial for proper functioning of the nervous system.

Question 53

Describe at least one way in which waves of a certain ion can begin propagating through networks of glial cells.

Question 54

Some important discoveries about the roles and functions of glial cells have come about due to the ability to observe them in vivo (alive). Explain one reason why studying live cells can be advantageous to studying dead cells.

Question 55

Glial cells have been found to release a number of possible transmitters in various situations. Provide one example of a transmitter that can be released by glial cells, as well as the presumed purpose of this release.

Question 56

The blood-brain barrier serves important functions. Describe its main function and suggest potential consequences if the blood-brain barrier did not exist.

Question 57

What is one consequence of the CNS having an immune response separate from the rest of the body?