:Q Flashcards

1
Q

define:

anterograde degeneration [1]
retrograde degeneration [1]
transneuronal degeneration [1]

A
  • *- anterograde degeneration:** when the axon distal to the site of injury degenerates
  • *- retrograde degeneration**: when the proximal segment starts to degenerate)
  • transneuronal degeneration: the death of neurons resulting from the disruption of input from or output to other nearby neurons.
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2
Q

what is wallerian degeneration?

A

Wallerian degeneration is an active process of retrograde degeneration of the distal end of an axon that is a result of a nerve lesion. It occurs between 7 to 21 days after the lesion occurs. After the 21st day, acute nerve degeneration will show on the electromyograph.

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3
Q

what is neurapraxia? [1]

what is axonotmesis?

what is neurotmesis?

which of the following are reversible?

A

neurapraxia: temporary loss of motor and sensory function due to blockage of nerve conduction (temporary damage to myelin). reversible

axonotmesis: disruption of the axons, resulting from severe crush or contusion. myelin and axon damaged. reversible (epineurium still intact)

neurotmesis: both the axons and nerve sheath are disrupted: 3rd degree damage. myelin and axon AND epineurium damaged. partial recovery possible

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4
Q

after nerve injury:

how does the cell communicate that its injured? [3]

what transformation does cell undergo (in function?) [1]

A

how does the cell communicate that its injured? [3]

  • get a burst of APs (alerts the cell body in DRG that damage has occurred)
  • disruption of retrograde transport flow of trophic support (this is a negative injury signal bc its a stop to normal procedure)
  • postive injury signals

= all alert DRG that is damaged !!

what transformation does cell undergo (in function?) [1]

cells in the DRG alter their phenotype (switch from transmission of information state to growth state.

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5
Q

how does nerve regeneration occur? which cells are involved

A

the process of nerve regeneration:

  • schwann cells divide & secrete trophic factors to attract axon then remyelinate new axons
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6
Q

spinal cord trauma produces what? occurs from here? [2]

what do macrophages and glial cells make when spinal cord injury occurs? [1]

A

spinal cord trauma produces what? occurs from here? [2]

site of primary cell death: rapidly spreads into a zone of secondary cell death|

then produces a zone of secondary cell death

(spinal cord injury occurs from both primary and secondary cell death)

macrophages and microglia engulf debri and injury site becomes walled off by a glial scar

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7
Q

what are the two main barriers to CNS repair?

A
  • *1. hostile environment**
    i) scar tissue
    ii) myelin-associated inhib proteins (NOGO proteins, MAG, OMGP)

2. poor regenerative response (unlike PNS)

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8
Q

spinal cord trauma produces what? occurs from here? [2]

what do macrophages and glial cells make when spinal cord injury occurs? [1]

A

spinal cord trauma produces what? occurs from here? [2]

site of primary cell death: rapidly spreads into a zone of secondary cell death|

then produces a zone of secondary cell death

(spinal cord injury occurs from both primary and secondary cell death)

macrophages and microglia engulf debri and injury site becomes walled off by a glial scar:

  • engulfs debris
  • seals lesion site
  • repairs the blood-spinal cord barrier
  • expresses chemicals that inhibit axon growth
    both a physical and chemical barrier for neuroregeneration
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9
Q

vestibulocochlear nerve:

where does the it arise from?
vestibular part [1]
cochlear part: [1]

A

vestibulocochlear nerve:

where does the it arise from? [2]
vestibular part: pons & medulla
cochlear part: cerebellar peduncle

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10
Q
A

A: midbrain - identified by the large cerebral peduncles
B: medulla (superior / open)
C: pons - iD by bugle at front
D medulla inferior

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11
Q

Which of the following extrinsic muscles of the tongue is not innervated by the hypoglossal nerve?

Styloglossus
Hyoglossus
​Genioglossus
Palatoglossus

A

Which of the following extrinsic muscles of the tongue is not innervated by the hypoglossal nerve?

Styloglossus
Hyoglossus
​Genioglossus
Palatoglossus: VN instead

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12
Q

Which foramen does the hypoglossal nerve travel through in the skull? [1]

A

Acceptable responses: Hypoglossal, Hypoglossal canal

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13
Q

the ribosomes in neuron cell bodies appear as clumps called what? [1]

A

nissil bodies

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14
Q

whar are the SL pictured here? [1]

what type of cell? [1]

A

whar are the white lines pictured here? [1]
schmidt-lanterman clefts

what type of cell? [1]
schwann cell

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15
Q

what is the role of satellite cells? [1]

where do you find? [1]

which type of staining? [1]

what do they look like? [1]

A

what is the role of satellite cells? [1]
help maintain the envrioment around neuronal body in the ganglion

where do you find? [1]
cells bodies of ganglia

which type of staining? [1]
H&E

what do they look like? [1]
cuboidal cells

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16
Q
A
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17
Q

which of the following provide physical & metabolic support for the neurons

oligodendrocytes
ependymal
astrocytes
microglial
schwann

A

which of the following provide physical & metabolic support for the neurons

oligodendrocytes
ependymal
astrocytes
microglial
schwann

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18
Q

which of the following helps to form BBB?

perineurium
endosteum
periosteal
endoneurium
epineurium

A

which of the following helps to form BBB?

perineurium
endosteum
periosteal
endoneurium
epineurium

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19
Q

what type of imaging is this?

CT
MRI T2
PET
Ultrasound
MRI T1

A

what type of imaging is this?

CT
MRI T2
PET
Ultrasound
MRI T1

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20
Q

what is A?

oligodendrocytes
ependymal
astrocytes
microglial
schwann

A

what is A?

oligodendrocytes
ependymal
astrocytes
microglial
schwann

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21
Q

what is the difference between myeline sheath in CNS compared to produced in PNS? [4]

A
  • different myelin-specific proteins
  • fewer schmidt-lanterman clefts
  • no external lamina
  • nodes of ranvier larger
  • thinner
22
Q

how do you differentiate microglial cells?

A

elongated nuclei
small
when stained with heavy metals, exhbit short & twisted processes

23
Q

what is the cellular organisation of the cerebellum?

in the cortex [3]

in the white matter [1]

A
  • outer hypocellular layer
  • middle purkinje cell layer
  • inner / deep hypercellular granular lyaer

white matter:
- climbing fibres
- mossy fibres
(axons and supoorting cells)

24
Q

what are the three cellular layers of blood brain barrier? [3]

A

tigh junctions of the endothelial cells
continous endothelial basal lamina (pericytes)
end foot processes of astrocytes

25
Q

what is the cellular organisation of the cerebral cortex?

A
26
Q

how can you tell which is the pyramidal layer in the cerebral cortex? [1]

where is the pyramidal layer more developed? [2]

A

how can you tell which is the pyramidal layer in the cerebral cortex? [1]
larger cell bodies

where is the pyramidal layer more developed? [2]
motor & sensory centres

27
Q

which cell does the pink arrow point to? (and the other dark cells)

satellite
astrocytes
oligodendrocytes
microglial
ependymal

A

which cell does the pink arrow point to? (and the other dark cells)

satellite
astrocytes
oligodendrocytes
microglial
ependymal

28
Q

which area of the brain contains most of the dopamine neurons in the brain?

cerebellum
temporal
midbrain
occipital
​frontal

A

which area of the brain contains most of the dopamine neurons in the brain?

cerebellum
temporal
midbrain
occipital
​frontal

29
Q

which structures in the brain does CT angiography specifically visualise? [2]

apart from looking at ischaemic stroke, what can CT angiography be used for? [1]

A

which structures in the brain does CT angiography specifically visualise? [2]
carotid arteries (External & internal)
circle of willis

apart from looking at ischaemic stroke, what can CT angiography be used for? [1]
aneurysms

30
Q
A
31
Q

what is fluid, muscle and fat appearance like in T1 / T2?

A

T1:

  • fluid: black
  • muscle: grey
  • fat: white

T2:

  • fluid: white
  • muscle: grey
  • fat: white
32
Q

what can be used as T1 MRI contrast agent? [1]

A

gadolinium

33
Q

which type of imaging is this?

CT venogram
PET scan
CT angiography
CT perfusion
MRI

A

which type of imaging is this?

CT venogram
PET scan
CT angiography
CT perfusion
MRI

34
Q

what type of imaging is this?

CT
MRI T2
PET
Ultrasound
MRI T1

A

what type of imaging is this?

CT
MRI T2
PET
Ultrasound
MRI T1

35
Q

which of the following would you use to assess subdural haemorrhage?

CT venogram
plain CT head
CT angiography
CT perfusion
MRI

A

which of the following would you use to assess subdural haemorrhage?

CT venogram
plain CT head
CT angiography
CT perfusion
MRI

36
Q

what is the opercular cortex?

how does it differ between L & R ?

A

what is the opercular cortex?
cortex on the upper and lower ‘lips’ of the lateral fissure

how does it differ between L & R ?
left

37
Q

what characterises broca’s aphasia?

what characterises wernickes aphasia?

A

what characterises broca’s aphasia:

  • *- halting speech
  • repetitive
  • sense behind words, just cant get them out!**

what characterises wernickes aphasia
- speaks fluently but in almost meaningless way

38
Q

broca’s and wernickes areas are joined by WHAT? [1]

what is the name for when ^^ is damaged [1]

what is this charactersised by? [2]

A

broca’s and wernickes areas are joined by arcuate fasciculus

What is the name for when A is damaged? [1]
conduction aphasia

what is this charactersised by? [2]
difficulty reading aloud / read back something
but good comprehension

39
Q

broca and wernickes areas are supplied by which artery? [1]
know this !!

A

middle cerebral artery

40
Q

what is the function of the right Broca’s & Wernickes area? [3]

what is the name for lesion of these areas? ^ [1]

A
  • involved in non-semantic speech recognition and generation: inotation, rhthym and emphasis
  • *also: non-language communication skills:** body language / gesture

what is the name for lesion of these areas? ^ [1]
aprosodia

41
Q

which two pieces of evidence suggest that AP starts with at NMJ in skeletal muscle? [2]

A
  1. the latency of AP increases the further move from NMJ.
  2. source of greatest depolarisation in the NMJ is closest to the axon terminal
42
Q

what are minature End Plate Potentials cause by? [1]

A

random release of NT from vesicles sporadically binding with membrane

43
Q
A
44
Q

what determines whether u find more K inside & Na outside the cell?

A

Na / K ATPase

45
Q

what causes vesicles to be recycled in nervous system? [1]

A

clathrin

46
Q
A
47
Q

know this !!

how does EPSP occur in CNS cell? [4]

A
  • K+ is greater inside cell, Na+ greater outside
  • at rest, K can move across membrane (leak out of the K+ channels): leaves behind a negative resting potential
  • nicotinic Ach receptor is permeable to both Na- & K+ ions
  • Ach binds to Nicotinic Ach R: causes conformational change: gives rise to depolarisation (bc Na move in?)
  • *- activation gives rise to depolarisation of cell**
48
Q

how does IPSP occur in NS?

A

NT released that are associated with inhib: GABA & Cl-

  • GABA binds to GABAa receptor
  • this activates causes an increase in membrane conductance: Chloride ions moves inwards
  • *- causes inhib.**
49
Q

which are the two main inhib NTs of CNS?

  • which one is dom in brain [1]
  • which one is dom in spinal cord [1]
A

which are the two main inhib NTs of CNS?

  • which one is dom in brain: GABA - B 4 brain !!
  • which one is dom in spinal cord: glycine
50
Q
  1. where does Ach bind to ACh R (specifics !!)
  2. describe structure of Ach R

what happens when Ach binds to ACHR?

A

structure: α2βγð subunits; spans across inside of cell, cell membrane and outside of cell (where the binding sites are)

when 2 Ach binds to AchR: change in hydrophobic interactions in alpha helical structure = creates an ion pore

binding occurs of Ach occurs at C loops (of cysteine-cysteine bond)

51
Q
A
52
Q

what happens to GABA, glutamate & biological amines after they are initially used? [1]

A

all transported out of synaptic cleft !!

GABA: reuptaken into presynaptic terminals by GATs

biogenic amines: reuptaken into presynaptic terminals

glutamate: transported in both pre & post synaptic terminals and into adjacent glial cells.