02c: CNS Cells

Question 1

CSF exists in (X) space, between which meningeal layers?

Answer 1

X = subarachnoid;

Arachnoid and pia

Question 2

List the two potential spaces associated with meninges, where blood can collect during hemorrhage.

Answer 2

Epidural and subdural

Question 3

Tearing of (X) vessel where it meets dural venous sinus likely results in subdural hemorrhage.

Answer 3

X = cerebral vein (where it meets dural venous sinus)

Question 4

Tearing of (X) vessel likely results in epidural hemorrhage.

Answer 4

X = meningeal artery of skull

Question 5

(Like/unlike) other regions of body, fluid in blood (can/cannot) have unrestricted access to brain.

Answer 5

Unlike; cannot

Question 6

T/F: BBB exists in all regions of brain.

Answer 6

False - most, except for few small regions

Question 7

T/F: There’s only one mechanism by which substances are transported across BBB.

Answer 7

False - diverse mechanisms

Question 8

Neuroglial cells are divided into which categories? They’re divided based on (X).

Answer 8

X = size

Microglia and macroglia

Question 9

Astrocytes are in which specific category of (X) cells?

Answer 9

X = neuroglial

Macroglia

Question 10

Oligodendrocytes are in which specific category of (X) cells?

Answer 10

X = neuroglial

Macroglia

Question 11

(Astrocytes/oligodendrocytes) have more compact nucleus.

Answer 11

Oligodendrocytes

Question 12

Which cells responsible for immuno surveillance/patrol in brain?

Answer 12

Microglia

Question 13

T/F: Brain does not have a lymphatic system.

Answer 13

True

Question 14

Localized damage in brain will initially activate fast directional movement of (X) cells in attempt to do (Y).

Answer 14

X = microglia
Y = contain injury

Question 15

(X) form myelin in CNS.

Answer 15

X = oligodendrocytes

Question 16

Each process of (X) cell contacts and myelinates (Y) number of CNS axons.

Answer 16

X = oligodendrocyte
Y = one

Question 17

Each (X) cell contacts and myelinates (Y) number of CNS axons.

Answer 17

X = oligodendrocyte 
Y = multiple

Question 18

T/F: Oligodendrocyte cell size depends on size of axon/amount of myelin.

Answer 18

True

Question 19

T/F: Amount of myelin on axon depends on number of processes of oligodendrocyte.

Answer 19

False

Question 20

T/F: There is notable loss of neurons with age.

Answer 20

False

Question 21

T/F: Normal aging affects myelination/axons.

Answer 21

True

Question 22

Star-shaped macroglia, aka (X), include which types?

Answer 22

X = astrocytes

Protoplasmic and fibrous

Question 23

A (X) astrocyte is found near cell body, aka (grey/white) matter.

Answer 23

X = protoplasmic;

Grey

Question 24

A (X) astrocyte is found near cell axon, aka (grey/white) matter.

Answer 24

X = fibrous;

white

Question 25

Astroctye general functions:

Answer 25

1. Regulate ionic composition 2. Provide metabolic support 3. Recycle NT 4. GFAP (intermediate filaments) provide structural support 5. Insulation of synapses/nodes of ranvier

Question 26

GFAP stands for (X).

Answer 26

Glial fibrillary acidic protein

Question 27

Parts of neuron that aren't covered by synapses are covered by:

Answer 27

Astrocytes

Question 28

(X) processes have end feet which cover (Y).

Answer 28

``` X = astrocytes Y = blood vessels and brain/SC surface ```

Question 29

End feet of (X) that form membrane around (Y) is formally called (Z).

Answer 29

``` X = astrocytes Y = brain/SC Z = glia limitans ```

Question 30

Large populations of astrocytes are connected by:

Answer 30

Gap junctions

Question 31

Neuron is damaged. How do astrocytes respond?

Answer 31

1. Strip synapses (isolate damaged neuron) 2. Physical barrier to regeneration 3. Proliferate and wall off area of injury (astrocytic scar)

Question 32

Substance can pass into extracellular space by which mechanisms?

Answer 32

1. Paracellular (between cells) 2. Vesicular transport (through cells) 3. Fenestration (through pores in endothelium)

Question 33

The BBB exists between which vessels/space?

Answer 33

Between capillaries and extracellular fluid

Question 34

Which specific cells of which specific vessels form the BBB?

Answer 34

Endothelial cells of brain capillaries

Question 35

T/F: BBB has few caveolae and few pores.

Answer 35

False - NO pores

Question 36

T/F: The massive amount of gap junctions form the tight BBB seal.

Answer 36

False - massive amount of tight junctions

Question 37

(X) surround capillaries and provide secondary protective mechanism to assist BBB.

Answer 37

X = astrocytes

Question 38

(X) substances diffuse through BBB.

Answer 38

X = lipophilic (lipids, O2, CO2)

Question 39

(X) substances undergo facilitated transport through BBB.

Answer 39

X = glucose

Question 40

Most substances transported through BBB via:

Answer 40

Active transport

Question 41

Pericytes exist in (X) and function to (Y).

Answer 41

``` X = basement membrane of BBB Y = contribute to structural integrity of vasculature ```

Question 42

Which area(s) of brain allow for blood monitoring via contact with vascular space?

Answer 42

1. Area postrema (floor of 4th ventricle) | 2. Subfornical organ (near hypothalamus)

Question 43

Initiation of vomiting reflex is done by (X).

Answer 43

X = area postrema

Question 44

Subfornical organ functions to:

Answer 44

Detect osmolarity of blood

Question 45

(X) area(s) in brain secrete hormones/prohormones into blood.

Answer 45

X = pineal gland and hypothalamus

Question 46

Areas of brain that indiscriminately contact substances in blood are "walled off" from rest of brain via:

Answer 46

Tanycytes (modified astrocytes that form barrier)

Question 47

T/F: Astrocytes provide structural support to brain that isn't very good.

Answer 47

True

Question 48

CSF makes brain weight feel (X) times lighter.

Answer 48

X = 30

Question 49

T/F: CSF functions both to support brain weight and buffer external forces.

Answer 49

True

Question 50

List the ventricles in the brain. Star those that produce CSF.

Answer 50

1. Lateral ventricles (2)* 2. Third ventricle* 3. Fourth ventricle*

Question 51

Where does CSF flow once it flows out of the (X), and last, ventricle?

Answer 51

X = fourth; Into subarachnoid space

Question 52

Cerebral ventricles are lined by (X) cells, formally called (Y).

Answer 52

``` X = epithelial Y = ependymal ```

Question 53

T/F: The ependymal cells form multiple thick layers.

Answer 53

False - one thick layer

Question 54

T/F: The ependymal cells are not strongly connected.

Answer 54

True

Question 55

The cerebral ventricles are lined by (X) cells that contain which key projections?

Answer 55

X = epithelial (ependymal) Cilia

Question 56

(X) cells produce CSF. They're derived from (Y) cells and contain which key projections?

Answer 56

``` X = choroidal Y = ependymal ``` Microvilli

Question 57

Choroidal cells are (simple/cuboidal/columnar). They line (X) vessels that have which characteristic?

Answer 57

Columnar; X = capillaries Fenestrated (hole-y)

Question 58

T/F: CSF is made from plasma, but has different ionic composition than blood.

Answer 58

True

Question 59

The Blood-CSF Barrier is formed by what?

Answer 59

Tight junctions between the choroidal cells that surround capillaries

Question 60

Apertures in (X) ventricle allow CSF to gain access to subarachnoid space. List these apertures.

Answer 60

X = fourth 1. Foramina of Luskha (2) (lateral) 2. Foramen of Magendie (median)

Question 61

Drainage of CSF out of subarachnoid space and into (X) is through (Y) structures.

Answer 61

``` X = superior sagittal sinus Y = arachnoid granulations ```

Question 62

The (X) provides insight into metabolic status of CNS.

Answer 62

X = CSF