4.0 Histology of the CNS Flashcards

1
Q

What defines an ependymal cell as a choroid plexus cell histologically?

A

Association with pia mater and associated vasculature.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Do ependymal cells have a basal lamina?

A

Nope.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the functions of ependymal cells?

A

Movement and absorption of CSF .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the functions of astrocytes?

A
  • Buffer extracellular K+ levels.
  • Guide and physically support movements and locations of differentiating neurons.
  • Extend fibrous processes with perivascular feet that cover capillary endothelial cells and form the blood brain barrier. Also helps to move nutrients, wastes, and other metabolites between neurons and capillaries.
  • Helps with the removal of neurotransmitters from the microenvironment to help neurons “turn off.”
  • Filling tissue defects after CNS injury by proliferation to form an
    astrocytic scar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The proximal regions of astrocytes are reinforced by what protein?

Why do we care?

A

GFAP: Glial Fibrillary Acid Protein

GFAP can be preferentially stained to highlight astrocytes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the six layers of the neocortex?

A
  1. Plexiform Layer (molecular layer)
  2. Small pyramidal cell layer (external granular layer)
  3. Layer of medium pyramidal cells (external pyramidal cell layer)
  4. Granular layer (internal granular layer)
  5. Large pyramidal cell layer (ganglionic layer)
  6. Polymorphic layer (multiform / polymorphic cell layer)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where do we find the choroid plexus?

A

In the roof of the 3rd and 4th ventricles, and in parts of the lateral ventricular walls.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the histological changes associated with Alzheimer’s disease.

A

The gyri of the cortex thin, and the brain becomes smoother.

β-amyloid plaques and tau (τ) neurofibrillary tangles are identified on sections, as well as neuronal loss.

These plaques interrupt communication between neurons.

Tau proteins form “skeins.”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What cells are responsible for myelination of the CNS?

What embryological layer are these cells derived from?

A

Oligodendrocytes

Neuroepithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What cells are responsible for myelination of the PNS?

What embryological layer do these come from?

A

Schwann cells

Neural crest cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What motor proteins are used in anterograde and retrograde transport, respectively?

A

Anterograde = kinesin.

Retrograde = dynein.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the function of microglia in the CNS?

A

They are the primary defense from microbial invaders.

Originate from monocytes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What composes the blood - CSF barrier?

A

Tight junctions between epithelial cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is “neuropil?”

A

Neuropil: dense network of interwoven nerve fibers &
their branches and synapses, together with glial filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What molecules utilize slow transport, and which direction are they headed?

A

Anterograde only

Tubulin molecules, actin molecules, & neurofilament proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the function of the choroid plexus?

A

Modified ependymal cells release CSF.

17
Q

What is this tissue?

A
18
Q

Where do we find bipolar neurons?

A

Sensory neurons of the retina, olfactory mucosa,
and inner ear

19
Q

Where do we find unipolar / pseudounipolar neurons?

A

“Other” sensory neurons, including
the dorsal root ganglia & cranial ganglia

20
Q

What do we call the grainy substance found in a neuron?

A

Nissl substance / bodies.