Deck 5: Protecting and Maintaining the Adult Nervous System

Question 1

In order to determine whether a cell has recently divided

A) artificial lipids could be used to detect newly duplicated cell membranes
B) artificial thymidines could be used to detect newly duplicated DNA
C) artificial carbohydrates could be used to detect newly duplicated carbohydrates
D) all of the above

Answer 1

B

Question 2

Although most neurons do not divide after an organism reaches adulthood, limited neuronal cell division appears to continue in which of the following brain regions?

A) dentate gyrus of the hippocampus
B) somatosensory cortex of the parietal lobe
C) area postrema of the medulla
D) ventromedial nucleus of the hypothalamus
E) all of the above

Answer 2

A

Question 3

Consider figure 05-03. In the text This cell is known to be a neuron because

A) it expressed BrdU but not NeuN
B) it expresses GFAP but not NeuN
C) it expresses NeuN but not GFAP
D) it expresses GFAP but not BrdU
E) all of the above

Answer 3

C

Question 4

The picture below is a hippocampal section from an animal injected with tritiated thymidine shortly after birth and sacrificed two weeks later. What can you conclude from this image?

A) no cell division has occurred during this two-week period of time
B) the rate of cell division seems to be slower than before birth
C) the presence of radioactive thymidine in the image indicates DNA synthesis has occurred
D) all of the cells in the image are neurons
E) all of the above

Question 5

The brain volume significantly expands over the first 9 months after a human is born. What is most likely responsible for this change in brain volume?

A) increased number of glia cells and myelin
B) increased numbers of neurons
C) increased size of neurons
D) increase in bone mass and bone volume
E) all of the above

Question 6

The brain is protected from physical trauma by

A) the skull, with a globular shape that distributes force evenly
B) cerebrospinal fluid that is approximately the same density as the brain itself
C) the meninges, particularly the dura mater
D) all of the above

Question 7

The subarachnoid space lies between the arachnoid membrane and the _________________.

Question 8

Place the following events in order by numbering 1-3:
____ CSF moves into the subarachnoid space
____ CSF production in the floor of the lateral ventricles and roof of the 3^rd and 4^th ventricle
____ CSF crosses arachnoid membrane and moves into veins and venous sinuses

Question 9

An ultrasound of a 6 month old fetus shows abnormally large brain ventricles, similar to the image found in Figure 05-09. In the text One cause of this might be

A) reduced production of CSF
B) blockage of the cerebral aqueduct
C) incomplete fusion of the skull at the fontanelles
D) all of the above

Question 10

You are studying an environmental toxin that is sometimes found in the blood supply (circulation) in animals. The substance is a small hydrophilic (polar) molecule. What is most likely true regarding this molecule?

A) It will readily cross into the CSF
B) It is unlikely that it will cross into the CSF
C) The size of the molecule will determine whether it will cross into the CSF
D) The route of administration (for example, whether it is ingested or inhaled) will determine whether it will cross into the CSF

Question 11

The arachnoid membrane and subarachnoid space takes its name from its "spider web" appearance. What protein are these fibers composed of?

A) aquaporin
B) glucose transporters
C) collagen
D) actin
E) tubulin

Question 12

What is true of the lateral ventricles?

A) They might be considered the "1^st and 2^nd" ventricles
B) They are connected to each other via the foramina of Monro
C) They contain CSF
D) CSF is produced by the choroid plexus on the floor of the lateral ventricles
E) All of the above

Question 13

Brain tumors, ruptured blood vessels in the brain, and blockage of the flow of CSF are all dangerous and have the potential to cause catastrophic injury because of an increase in __________________.

Question 14

What is true about a subdural hematoma?

A) It may result from severe head trauma that damages veins that return blood to the saggital sinus
B) It results in the accumulation of blood between the dura mater and the arachnoid membrane
C) It results in hydrocephaly
D) all of the above

Question 15

How would you set up an experiment (similar to those performed by Ehrlich and Goldman) to test whether neural tissue is protected from molecules circulating in the bloodstream? Indicate which step would NOT be necessary.

A) choose a non-polar (lipophilic) dye to inject into animals
B) Inject dyes directly into the CSF
C) Inject dyes directly into the circulation
D) Examine the animal for the presence of dye in neural tissue
E) Examine the animal for presence of dye in non-neural tissues
F) All of the above steps are necessary to set up the experiment

Question 16

Specialized endothelial cells in the brain are responsible for much of the function of the blood-brain barrier. Which of the following characteristics allow this specialized activity?

A) gap junctions between cells
B) tight junctions between cells
C) transport proteins that allow glucose to cross from the circulation into the CSF
D) transport proteins that allow oxygen to cross from the circulation into the CSF
E) b and c only
F) b, c and d only

Question 17

First generation anti-histamines differ from newer anti-histamine drugs because the first generation drugs can ______________________________.

Question 18

You are designing a new anti-histamine drug for allergy relief, with greater ability to limit histamine-induced inflammation and therefore reduce symptoms like watery eyes and runny nose. What is important to keep in mind as you design this new molecule?

A) It should readily cross the blood-brain barrier
B) It should be less specific in its ability to bind histamine receptors than first generation anti-histamines
C) It should promote drowsiness
D) none of the above are true

Question 19

Predict what would happen in the arachnoid membrane if the cells of the arachnoid barrier had fewer tight junctions.

A) collagen might be broken down
B) CSF might not be able to enter the circulation
C) toxins might be able to enter the CSF from the circulation via veins in the brain
D) all of the above

Question 20

Predict what would happen in the arachnoid membrane if the cells of the arachnoid barrier were exposed to a drug that limited their ability to form membrane-bound vacuoles.

A) toxins might be able to enter the CSF from the circulation via veins in the brain
B) CSF might not be able to move to the circulation
C) collagen might be broken down
D) all of the above

Question 21

Predict what would happen if you injected a hydrophilic (polar) drug directly into the CSF.

A) The drug would not be detectable in the veins of the brain
B) The drug would be detectable in small amounts in the veins of the brain
C) The drug would be detectable in the CSF and subarachnoid space only
D) None of the above

Question 22

The structures in the cells of the arachnoid membrane that carry CSF are known as

A) giant vacuoles
B) microvesicles
C) granulated vesicles
D) none of the above

Question 23

The parts of the brain where substances can cross from the circulation into neural tissue are known as the ______________________.

Question 24

A polar (hydrophilic) molecule has crossed from the circulation into neural tissue. What is the most likely explanation as to where this occurred?

A) the arachnoid barrier, where CSF drains into the venous return
B) the blood-CSF barrier composed of choroid epithelial cells
C) the blood-brain barrier composed of endothelial cells
D) the endothelial cells surrounding vasculature that supplies blood to the circumventricular organs
E) all of the above

Question 25

Rate the effectiveness of the following barriers at preventing substances from crossing as either VERY permissive or NOT permissive:
_____ the arachnoid barrier, where CSF drains into the venous return (in the direction of CSF to circulation)
_____ the arachnoid barrier, where CSF drains into the venous return (in the direction of circulation to CSF)
_____ the blood-CSF barrier composed of choroid epithelial cells
_____ the blood-brain barrier composed of endothelial cells
_____ the endothelial cells surrounding vasculature that supplies blood to the circumventricular organs

Question 26

The circumventricular organs

A) allow the brain to detect circulating toxins in the bloodstream
B) allow the brain to detect dissolved gasses in the bloodstream
C) allow the brain to detect changes in blood composition that would indicate dehydration
D) all of the above

Question 27

Which of the following can weaken barriers in the brain?

A) physical trauma
B) meningitis
C) diseases such as cancer and multiple sclerosis
D) all of the above

Question 28

The innate immune response generates __________________.

Question 29

Which of the following is true of the innate immune response?

A) it causes the release of cytokines and chemokines
B) it causes cells to bind pathogens and migrate to the lymph nodes
C) it causes lymphocyte activation
D) all of the above

Question 30

Identify which of the following is true of the adaptive immune system?

A) it is slower than the innate immune response
B) it causes cells to bind pathogens and migrate to the lymph nodes
C) it causes lymphocyte activation
D) all of the above

Question 31

Contrast innate and adaptive immunity by selecting the correct statement:

A) adaptive immunity occurs in the brain, while innate immunity occurs outside the brain
B) adaptive immunity is fast, while innate immunity is slow
C) innate immunity is non-specific, while adaptive immunity is specific
D) all of the above

Question 32

Identify the problem associated with an understanding of adaptive immunity as it relates to neural tissue.

A) pathogens are not likely to be found in neural tissue
B) immune cells might have a difficult time crossing barriers where adjacent cells are linked by tight junctions
C) adaptive immunity is not capable of a rapid enough response to brain infections
D) all of the above

Question 33

Match the event with the type of immunity
-________________ cytokine release and inflammation

A) innate
B) adaptive

Question 34

Match the event with the type of immunity
-________________ lymphocyte response and antibody production

A) innate
B) adaptive

Question 35

Match the event with the type of immunity
-________________ rapid response

A) innate
B) adaptive

Question 36

Match the event with the type of immunity
-________________ slow response to a novel (new) antigen

A) innate
B) adaptive

Question 37

Put the following events in order from 1 to 7 as related to adaptive immunity.
____ B cells (specialized lymphocytes) divide, and each new B cell can produce antibodies
____ antibodies bind to antigen
____ B cells (specialized lymphocytes) respond to an antigen presented in the lymph node
____ lymphocytes encounter an antigen
____ lymphocytes migrate to lymph node
____ an antigen enters the circulation
____ macrophages and "killer cells" remove or neutralize the antigen

Question 38

Examine the evidence that the central nervous system is "immune privileged". What is a central observation that leads to this idea?

A) CSF eventually drains into lymphatic ducts inside the nose
B) tissue grafts are rejected when in the periphery, but not at all (or very slowly) in the brain
C) tissue grafts in the ventricles trigger rapid rejection
D) all of the above

Question 39

There is considerable evidence that immune cells can enter the CSF. One theory as to why these same cells cannot readily cross into the brain parenchyma is because ____________________ prevent their crossing or reduce their effectiveness.

Question 40

What is true of microglia?

A) they move toward chemical signals
B) they do not multiply
C) they prevent cells from being engulfed
D) all of the above

Question 41

Select what might happen if a person is afflicted with meningitis.

A) the function of the brain barriers would decrease
B) immune cells could cross into affected areas
C) neurons would be impervious to destruction by inflammatory processes
D) a and b only
E) all of the above

Question 42

Necrosis

A) results in the death of a cell
B) spills the contents of the cell into adjacent areas
C) can harm nearby cells via glutamatergic excitotoxicity
D) all of the above

Question 43

Choose whether the event below describes necrosis or apoptosis.
-__________ cell ruptures and releases contents in an uncontrolled manner

A) necrosis
B)apoptosis

Question 44

Choose whether the event below describes necrosis or apoptosis.
-__________ cell systematically dismantles its components

A) necrosis
B)apoptosis

Question 45

Choose whether the event below describes necrosis or apoptosis.
-__________ can be caused by glutamate-induced excitotoxicity

A) necrosis
B)apoptosis

Question 46

Choose whether the event below describes necrosis or apoptosis.
-__________ minimizes damage to neighboring cells

A) necrosis
B)apoptosis

Question 47

Choose whether the event below describes necrosis or apoptosis.
-__________ rarely occurs in neurons

A) necrosis
B)apoptosis

Question 48

Potassium buffering refers to

A) ensuring enough potassium is available to allow an action potential
B) glial cells removing potassium from areas of high neuronal activity
C) microglia engulfing potassium as part of the innate immune response
D) all of the above

Question 49

Glial scars formed by reactive astrocytes are bad in the sense that they inhibit axonal regrowth. In contrast, treatment that limits glial scarring might

A) also limit reactive astrocytes' ability to take up glutamate and other toxic molecules
B) also limit reactive astrocytes' ability to take up potassium
C) also limit reactive astrocytes' ability to engulf pathogens
D) all of the above

Question 50

Differentiate between oligodendrocytes and Schwann cells.

A) oligodendrocytes are found in the CNS, while Schwann cells are found in the PNS
B) oligodendrocytes tend to inhibit axonal regrowth, while Schwann cells promote regrowth
C) oligodendrocytes myelinate neurons, while Schwann cells only provide growth cues
D) a and b only
E) all of the above

Question 51

The story of the non-sighted woman who had a stroke in her occipital cortex and lost her ability to read Braille supports the idea that

A) the occipital cortex normally plays a large role in processing language
B) neural connections are dynamic and form throughout a person's lifetime
C) the brain's plasticity is dependent on a properly functioning occipital cortex
D) all of the above

Question 52

A short summary of constraint-induced movement therapy would indicate that it

A) is supported by the work of Edward Taub
B) relies on remapping of brain connections
C) improves patient outcomes as compared to controls
D) all of the above

Question 53

At rest, the brain uses around ______% of the body's total energy consumption.

Question 54

Decide which of these cells (NEURON, NON-NEURON, or BOTH) is described by each statement below.
_______________ can employ a variety of metabolic pathways to synthesize glucose
_______________ uses glycolysis and oxidative phosphorylation to generate ATP
_______________ must uptake glucose from extracellular environment
_______________ can use lipids and amino acids as an energy source

Question 55

Glycogen is stored primarily in what cell type in the brain?

A) microglia
B) astrocytes
C) neurons
D) oligodendrocytes
E) all of the above

Question 56

Examine figure 5-22. In the text The reason you can take your pulse in your carotid artery on one side of your neck and not cause ischemic injury is because

A) the other carotid artery increases in size (dilates) to compensate
B) the brain can go up to 20 minutes without an active blood supply
C) the circle of Willis and communicating arteries allow circulation in the brain to continue
D) all of the above

Question 57

Examine Figure 23B. In the text As a result of blockage, which of the following has happened?

A) circulation has remained the same
B) circulation has been re-routed through anastomoses
C) the circulation in all vessels has been reversed
D) all of the above

Question 58

Fill in the blank with UNIDIRECTIONAL or BIDIRECTIONAL. In general, the brain's principal arteries and surface arterioles are _____________________, but the penetrating arterioles are _____________________ with regard to the direction of blood flow.

Question 59

The reason that we can rely on fMRI to measure brain activity is because

A) the presence of increased blood flow in a given area indicates that the brain is active in that same area
B) oxygenated blood is only found in regions of the brain that are active
C) hemoglobin is actively transported out of neurons in areas of the brain that are active
D) all of the above

Question 60

Place the following events in order regarding the regulation of blood flow to active brain regions by writing 1-4 in the blank spaces.
_____ many neurons become active, releasing glutamate as a neurotransmitter
_____ calcium levels rise in astrocyte endfeet
_____ blood vessels dilate
_____ astrocytes detect glutamate via glutamate receptors

Question 61

Analyze figure 5-26A in the text . Two differences between these four images are __________________ and __________________.

Question 62

Descartes and other philosophers have pondered a thought experiment known as the ___________________, which relies on a disembodied brain.

Question 63

Point out biological problems would be difficult to solve if the "brain-in-a-vat" experiment were ever tried in real life. Some of these would include:

A) how to provide oxygen and glucose to brain tissues
B) how to drain this fluid in a manner that doesn't expose the brain to toxins or pathogens
C) how to keep neurons from dividing
D) a and b only
E) all of the above

Question 64

Predict whether the technique called "carbon dating for neurons" will likely replace methods based on artificial thymidines in modern research labs. Justify your response.

Question 65

Predict possible side-effects of morphine (an opiate pain reliever) based on its role in the gastrointestinal system. Look up information on the internet about morphine and its side effects. Were you correct in your prediction?

Question 66

A person ingests a polar compound that is detected by the circumventricular organ. Predict whether this compound could be detected later in the CSF. Justify your prediction.