Neurohistology and Nervous System repair Flashcards Preview

MD4001 Anatomy > Neurohistology and Nervous System repair > Flashcards

Flashcards in Neurohistology and Nervous System repair Deck (58)
1

Where is the subarachnoid space

between the pia and the arachnoid mater

2

what is a perikaryon

neuron cell body

3

what is a multipolar neuron

cell body at one end

4

what is bipolar neuron

cell body in the middle

5

what is a pseudopolar neuron

cell body in the middle, on a stalk

6

what is found in grey matter

cell bodies

7

what is found in white matter

axons

8

what is the axon hillock

where the cell body meets the axon

9

what does nissl substance stain

ER and polyribosomes

10

what is the neocortex

cerebral cortex

11

how many layers of the cerebral cortex are there

6

12

how many layers of the cerebellar cortex are there

3

grey superficially and white is deep

13

what are the layers of the cerebellar cortex

molecular
purkinje cells
granular

14

what is found in the granular layer

granular cells and golgi cells

15

what is found in the molecular layer

basket cells, stellate cells and fibres

16

describe purkinje cells

multipolar neurons
largest cells in the cerebellum
pear shaped
dendritic tree which expands outwards into the molecular layer

receive afferent information from the CNS

17

Where are astrocytes, oligodendroglia, ependymal cells and microglia found

the CNS

18

where are schwaan cells and satelite cells found

PNS

19

what do oligodendroglia and schwaan cells do

form myelin sheaths

20

what do astrocytes do

structural and metabolic support for neurons

21

where are fibrous astrocytes found

white matter of the CNS

22

Where are protoplasmic astrocytes found

grey matter of the CNS

23

where are muller glia found (astrocytes)

retina

24

where are radial glia (astrocytes) found

developing CNS

25

What forms the BBB

endothelial cells, tight junctions and astrocyte end feet

26

what is the maximum weight allowed through the BBB

500 daltons

27

what is the function of ciliated cuboidal ependymal cells

line the ventricle, secrete and reabsorb CSF

28

where is CSF produced

chroroid plexus

29

what is the function of microglia

immune function like macrophages, able to phagocytose cell debris upon injury
release cytokines

30

what are the functions of oligodendrocytes

one cell is able to myelinate several axons

31

what cells is affected in MS and leukodystrophy

oligodendrocytes

32

how many schwaan cells can myelinate one axon

1 cell per axon

33

what is the function of myelin

Insulation and increased velocity via saltatory conduction

34

what axons are unmyelinated

fibres carrying pain, temperature and itch

35

describe unmyelinated axons in the PNS

enveloped by schwaan cells

this does not happen in the CNS

36

what are ganglia

aggregations of nerve cells outside the CNS

37

what are ganglion cells surrounded by

flattened satellite cells (fibroblasts)

38

what is the perineurium

surrounds several axons in order to create a fascicle

39

what is the epineurium

surrounds several fascicles

40

what is the endonerium

surrounds individual nerve fibres

41

what is found in the lateral part of the spinal cord grey matter

autonomic motor neurons

42

what is found in the anterior part of the grey matter in the spinal cord

somatic motor neurons

43

what is found in the posterior horns of the grey matter in the spinal cord

interneurons (reflexes)

44

what is found in white matter in the spinal cord

ascending and descending tracts

mostly paired and decussate

45

what is found in anterior white matter columns

motor

46

what is found in lateral white matter columns

motor or sensory

47

what is found in dorsal white matter columns

sensory

48

where is the median fissure

anterior

49

where is the median sulcus

posterior

50

what is the histological appearance of motor neurons in the spinal cord

multipolar
cell bodies are large and found in the ventral horn
large pale staining nucleus
prominent nucleolus
nissl bodies

51

can peripheral nerves be repaired

yes

CNS axons cannot

52

what is Wallerian degeneration

after trauma the PNS and CNS repairs by clearing debris and lays the foundation for regrowing nerve fibres

does not work properly in the CNS, also inhibitory factors in the environment contributing to failed repair

53

describe the process of Wallerian degeneration in the PNS

injury causes fragmentation of the axon and myelin sheath

schwaan cells become reactive and proliferate

macrophages phagocytose debris

schwaan cells express growth factor and form bands of Bungner
nerve fibres grow towards the bands

nerve fibres reconnect with end organs and are remyelinated by schwaan cells

54

Why does Wallerian degeneration fail in the CNS

inflammation
myelin debris is not completely removed
glial scar is formed by reactive astrocytes astrocytes

regrowth of axons is inhibited by myelin debris and glial scar

a cystic cavity forms

lack of growth promoting molecules and an inhibitory environment

may have reactive end bulbs

oligodendrocytes > myelin debris
astrocytes > glial scar

55

describe reactive astrocytes after injury

hypertrophy
expression of inhibitory molecules and normal molecules which forms a glial scar which the axon cannot pass through

56

where are glial cells segregated into CNS or PNS

glial limiting membrane at the dorsal root entry zone

57

what is the substantia gelatinosa

a mass of gelatinous gray matter that lies on the dorsal surface of the dorsal column and extends the entire length of the spinal cord into the medulla oblongata and transmits painful sensory information.

58

what is the gracile fasculus

carries information from the lower limbs

found in the posterior column medial lemniscus pathway