neurology cells

Question 1

neurons - function

Answer 1

signal-transmitting cells of the nervous system

Question 2

neurons - proliferation status

Answer 2

permanent cells - do not divide in adulthood

Question 3

neurons - structure and function of every part

Answer 3

signal relaying cells
dendrites - receive input
cell bodies
axons send input

Question 4

neurons cell bodies and dendrites can be seen on

Answer 4

Nissle staining (stains RER)

Question 5

in neurons cells, Nissle stains …. (part) why

Answer 5

Cell bodies and dendrites, not the axon because there are not RERs

Question 6

Injury of axon of neuron –> .. ..

Answer 6

Wallerian degeneration: degeneration distal to injury and axonal retraction proximally

Question 7

Wallerian degeneration - purpose

Answer 7

allows for potential regeneration of axon (if in peripheral)

Question 8

astrocytes - marker and origin

Answer 8

marker: GFAP
origin: neuroectoderm

Question 9

astrocytes - function

Answer 9

1. physical support
2. repair
3. removal of excess neurotransmitter
4. component of BBB
5. glycogen fuel reserve buffer
6. K+ metabolism
7. reactive gliosis in response to neural injury

Question 10

astrocytes - response to neural injury

Answer 10

Reactive gliosis

Question 11

Microglia function / origin

Answer 11

Phagocytic scavenger cells of CNS

origin: mesodermal, mononuclear origin

Question 12

Microglia - activation

Answer 12

in response to tissue damage

Question 13

Microglia - staining

Answer 13

not readily discernible by Nissl stain

Question 14

Microglia vs HIV

Answer 14

microglia infected by HIV fuse to form multinucleated giant cells in CNS

Question 15

Myelin is made of

Answer 15

• CNS - oligodendrocytes

- PNS - Schwann cells

Question 16

Myelin - mechanism of action

Answer 16

Wraps and insulates axons –> saltatory conduction of action potential at nodes of Ranvier, where there are high concentrations of Na+ channels –> increases 1. space constant 2. conduction velocity

Question 17

condition that destroys Schwann cells

Answer 17

Acute inflammatatory demyelinating polyradiculopathy (Guillain-Barre syndrome)

Question 18

Schwann cells - derived from

Answer 18

neural crest

Question 19

Schwann cells - function / origin

Answer 19

1. myelinates PNS axon
2. promote axonal regeneration
   origin: neural crest

Question 20

nobes of Ranvier - high concentration of

Answer 20

Na+ channels

Question 21

astrocytes, microglia, Schwann cells, oligodendroglia - derived from

Answer 21

astrocytes –> neuroectoderm
microglia –> mesodermal, mononuclear origin
Schwann cells –> neural crest
oligodendroglia –> neuroectoderm

Question 22

Acustic neuroma - if bilateral, strongly associated with…. / typically located

Answer 22

NF2

typically located in internal acoustic meatus (CN III) –> may extend to cerebellopontine angle

Question 23

oligodendrocytes - histological appearance and function

Answer 23

fried egg

myelinates axins of neurons in CNS

Question 24

oligodendrocytes VS Schwann cells according function

Answer 24

1. Schwann myelinates PNS axons while oligodendrocytes axons in CNS
2. One Schwann myelinates 1 axon while oligodendorcyte a lot (~30)

Question 25

conditions with injured oligodendroglia

Answer 25

1. multiple sclerosis 2. progressive multifocal leukoencephalopathy 3. leukodistrophies

Question 26

peripheral nerve structure - from outer to inner

Answer 26

Epineurium - perineurium - endoneurium

Question 27

peripheral nerve structure - epineurium?

Answer 27

dense connective tissue that surrounds entire nerve (fascicles and vessels)

Question 28

peripheral nerve structure - perineurium?

Answer 28

surrounds a fascicle of nerve fibres

Question 29

Predominant type of glial cells in white matter

Answer 29

oligodendrocytes

Question 30

peripheral nerve structure - endoneurium?

Answer 30

invests single nerve fibers layers

Question 31

peripheral nerve structure - for limb reattachment

Answer 31

perineurium must be rejoined microsurgery

Question 32

peripheral nerve structure - inflammatory infiltrate in Guillain Barre syndrome

Answer 32

endoneurium

Question 33

BBB function

Answer 33

prevents circulating blood substances (eg. bacteria, drugs) from reaching CSF/CNS

Question 34

BBB - number of structures and structures

Answer 34

3 structures: 1. tight junctions between nonfenestrated capillary endothelial cells 2. Basement membrane 3. Astrocyte foot processes

Question 35

example of substances that crosses BBB and how

Answer 35

glucose --> slowly by carrier-mediated transport mechanism amnoacids --> slowly by carrier-mediated transport mechanism Nonpolar/lipid-soluble --> rapidly via diffusion

Question 36

CNS - fenestrated capillaries

Answer 36

a few specialized brain regions with fenestrated capillaries and no blood-brain barrier allow molecules in blood to affect brain function

Question 37

CNS - fenestrated capillaries - functional anatomy examples

Answer 37

1. area postrema ( medullary structure) - vomiting after chemo 2. Vascular organ of lamina terminalis - osmotic sensing 3. neurosecretory products (ADH - neurohypophysis)

Question 38

Beside BBB, other notable barriers includes

Answer 38

Blood-testis barrier | Maternal-fetal blood barrier of placent

Question 39

Vasogenic edema mechanims

Answer 39

cerebral edema in which the BBB is disrupted (damaged endothelial cell tight junction)

Question 40

Vasogenic edema - causes

Answer 40

1. infraction | 2. neoplasm

Question 41

Osmotic demyelination syndrome is also called

Answer 41

central pontine myelinolysis

Question 42

Osmotic demyelination syndrome (central pontine myelinolysis) can cause

Answer 42

1. acute paralysis 2. dysarthria 3. dysphagia | 4. diplopia 5. loss of consciousness 6. locked in syndrome

Question 43

locked in syndrome - definition

Answer 43

body and most of the facial muscles are paralysed but consciousness remains and the ability to perform certain eye movements is preserved.

Question 44

Osmotic demyelination syndrome (central pontine myelinolysis) - pathophysiology

Answer 44

massive axonal demyelination in pontine white matter secondary to osmotic damage

Question 45

Osmotic demyelination syndrome (central pontine myelinolysis) - MCC

Answer 45

iatrogenic - overly rapid correction of hyponatremia

Question 46

correcting hypernatremia too quickly results in

Answer 46

cerebral edema/herniation

Question 47

correcting of serum Na+ too fast can cause

Answer 47

from low to high --> Osmotic demyelination syndrome | from high to low --> cerebral edema/herniation

Question 48

CNS - fenestrated capillaries - functional anatomy examples

Answer 48

1. area postrema ( medullary structure) - vomiting after chemo 2. Vascular organ of lamina terminalis - osmotic sensing 3. neurosecretory products (ADH - neurohypophysis)