histology of CNS

Question 1

what are glia?

Answer 1

support cells, involved in:
conduction speed
repair
neurotransmitter maintenence

Question 2

what is neuropil

Answer 2

network of interwoven nerve fibers and glial filaments

Question 3

what is the basic anatomy of a typical neuron

Answer 3

large cell body
long, myelinated axon
lots of branching dendrites

Question 4

what is a terminal arborization

Answer 4

distal end of an axon

Question 5

what is telodendria

Answer 5

a dilation at the branch end of an axon where it contacts postsynaptic cell

Question 6

what is the most common neuron in the CNS

Answer 6

multipolar

Question 7

where are bipolar neurons found

Answer 7

retina
olfactory mucosa
inner ear

Question 8

what neuron type is found within the dorsal root and cranial ganglia

Answer 8

unipolar/pseudounipolar

Question 9

what do anaxonic neurons do?

Answer 9

regulate local electrical changes of adjacent neurons

DO NOT PRODUCE APs

Question 10

which axonal transport system carries material from the nerve cell body to the periphery?

Answer 10

anterograde transport

Question 11

what mechanism is used for anterograde transport

Answer 11

ATP-dependent kinesin (microtubule associated motor protein)

Question 12

which axonal transport system carries material from the axon terminal/dendrites to the cell body?

Answer 12

retrograde transport

Question 13

what mechanism is used for retrograde transport

Answer 13

dynein (microtubule associated motor protein)

Question 14

is retrograde transport slow or fast

Answer 14

fast only

Question 15

what molecules are carried via slow transport

Answer 15

tubulin and actin molecules

neurofilament proteins

Question 16

what organelles are found at the presynaptic terminal bouton

Answer 16

mitochondria,

synaptic vesicles

Question 17

how does current flow occur in an electrical synapse

Answer 17

gap junctions

Question 18

what is the function of connexon proteins in an electrical synapse?

Answer 18

permit diffusion of small molecules

electric current flow

Question 19

what are the four types of glial cells

Answer 19

astrocytes
oligodendrocytes
microglial cells
Ependymal cells

Question 20

what are the structural characteristics of an astrocyte?

Answer 20

lots of long, branching processes

reinforced by GFAP

Question 21

what is the function of astrocytes

Answer 21

regulate extracellular [ions]
support neurons
fill in tissue damage (astrocytic scar)

Question 22

what is the function of the perivascular feet of astrocytes?

Answer 22

cover capillary endothelial cells, modulate blood flow

Question 23

what is the function of oligodendrocytes?

Answer 23

wrap around axons => cytoplasm leaves => myelin

Question 24

how do oligodendrocytes appear on histo slide?

Answer 24

unstained cytoplasm

round, condensed nucleus

Question 25

what are oligodendrocytes derived from embryologically

Answer 25

neuroepithelium

Question 26

what is the counterpart of oligodendrocytes in the PNS?

Answer 26

Schwann cells

Question 27

what are the structural characteristics of ependymal cells

Answer 27

columnar/cuboidal cells lining ventricles of the brain and central canal of spinal cord apical end w/ cilia and microvilli no basal lamina

Question 28

what is the function of ependylmal cells

Answer 28

facilitate CSF movement | absorption

Question 29

what are the structural characteristics of choroid plexus

Answer 29

folded highly vascular roofs 3rd and 4th ventricles thin layer of pia covered w/ ependymal cells

Question 30

what is the function of choroid plexus

Answer 30

removes H2O from blood, releases it to CSF

Question 31

what are microglia derived from

Answer 31

monocytes

Question 32

what is the function of microglia

Answer 32

remove damages/inactive synapses | IMMUNE DEFENSE of CNS

Question 33

where is the central canal of the spinal cord?

Answer 33

within the central commissure of grey matter

Question 34

what is found within the central canal

Answer 34

CSF | lined by ependymal cells

Question 35

what glial cells are found in abundance within the grey matter of the spinal cord?

Answer 35

astrocytes

Question 36

what glial cells are found in abundance within the white matter of the spinal cord?

Answer 36

oligodendrocytes

Question 37

what are the three layers of the cerebellar cortex?

Answer 37

molecular layer purkinje cells granular layer

Question 38

which layer of the cerebellar cortex contains small, densely packed neurons and little neuropil

Answer 38

granular layer

Question 39

which layer of the cerebellar cortex has a lot of neuropil and scattered cell bodies

Answer 39

molecular layer

Question 40

what are the 6 cortical layers?

Answer 40

``` I. plexiform II. small pyramidal cell layer III. layer of medium pyramidal cells VI. granular layer V. large pyramidal cell layer VI. polymorphic layer ```

Question 41

which cortical layer consists mostly of parallel fibers, neuroglial cells and horizonal cells of cajal

Answer 41

plexiform layer (I)

Question 42

in what cortical layer are there very large pyramidal cells

Answer 42

large pyramidal cell layer (V)

Question 43

what cortical layer is characterized by many small granule cells

Answer 43

granular layer (IV)

Question 44

how does the middle cell layer of the hippocampus differ from that of the dentate gyrus

Answer 44

the middle cell layer of the hippocampus contains pyramidal cells the dentate gyrus has dentate granule cells with round cell bodies

Question 45

what is the hilus?

Answer 45

the region where the head of the hippocampus touches the dentate gyrus

Question 46

what is the role of mossy cells within the hilus?

Answer 46

receive input from fibers of dentate granule cells => relay signals to other dentate cells

Question 47

what gyri may are markedly thinned in alzheimers dz?

Answer 47

gyri of the frontal and temporal lobes

Question 48

where are amyloid plaques?

Answer 48

in the cortex of pt's w/ alzheimers

Question 49

abnormal accumulation of tau results in what hallmark of alzheimer's

Answer 49

neurofibrillary tangles

Question 50

what neural cell is associated with GFAP

Answer 50

astrocytes

Question 51

what cells are the macrophages of the CNS?

Answer 51

microglia

Question 52

what is the key difference between Schwann cells and oligodendrocytes

Answer 52

each oligodendrocyte myelinates MULTIPLE axons | each Schwann cell myelinates A SINGLE axon