CNS cell types Flashcards Preview

neuroanatomy > CNS cell types > Flashcards

Flashcards in CNS cell types Deck (17)
Loading flashcards...
1
Q

Name the three main glial cells in the CNS

A
  • Oligodendrocytes
  • Microglia
  • Astrocytes
2
Q

Describe upper motor neurons

A
  • large
  • Excitatory
  • Glutamatergic
  • Long projection pyramidal cells
3
Q

Describe striatal interneurons

A
  • Small
  • Inhibitory
  • GABAergic
4
Q

Describe Oligodendrocytes

A
  • Myelinating cells of the CNS
  • Unique to vertebrates
  • Provide metabolic support for axon and enable rapid nerve conduction
  • Demyelinating diseases e.g. multiple sclerosis
5
Q

describe the myelin sheath

A
  • formed by wrapping of axons by oligodendroctye processes
  • highly compared (70% lipid, 30% protein)
  • myelin specific proteins (MBP, MAG, MOG, PLP, PMP22) involved in compaction - excellent markers
6
Q

Describe microglia

A
  • Resident immune cells of the CNS
  • resting state, highly ramified, motile processes survey environment
  • upon activation (ATP) retract processes, become amoeboid and motile
  • proliferate at sites of injury (phagocytic)
7
Q

Functions of microglia

A
  • Immune surveillance
  • phagocytosis (debris/microbes)
  • synaptic plasticity - pruning
  • process dynamics
8
Q

Describe astrocytes

A
  • Star-like cells
  • Highly heterogeneous
  • most numerous glial cells in the CNS
  • common marker GFAP
9
Q

Types of astrocyte

A

Fibrous - white matter, less elaborate, contacts with blood vessels, pia surface and nodes of ranvier
Protoplasmic - grey matter, extremely elaborate, processes contact blood vessels and pia surface

10
Q

Astrocyte functions

A
  • developmental (radial glia)
  • structural (define brain micro-architecture)
  • envelope synapses (tripartite synpase)
  • homeostatic (buffer K+, glutamate etc.)
  • support neurons (glutamate-glutamine shuttle, lactate shuttle)
  • neurovascular coupling (basis of fMRI)
  • disease (gliosis/astrocytosis)
11
Q

Specialised astrocytes

A
  • Radial glia (stem-like progenitor cells, developmental)
  • Muller glia (specialised radial glia of the retina)
  • Bergmann glia (cerebellum, extremely elaborate, purkinje cell dendrites and synapses)
12
Q

CNS terminology

A
  • abundance of neuronal cell bodies in nuclei
  • axons gathered into tracts
  • tracts that cross midline = commissures
  • grey matter contains neural cell bodies and processes
  • neuropil contains few cell bodies
  • white matter contains abundance of myelinated tracts and commissures
13
Q

PNS terminology

A
  • cell bodies and supporting cells located in ganglia
  • axons bundled into nerves
  • many PNS axons are enveloped by Schwaan cells (myelinating cells of the PNS)
14
Q

What is the BBB formed by

A
  • endothelial tight junctions
  • pericytes
  • astrocyte end feet
  • continuous basement membrane
15
Q

What is the BBB sensitive to

A
  • inflammation
  • hypertension
  • trauma
  • ischaemia
16
Q

Describe ependymal cells

A
  • epithelial-like, line ventricles and central canal of spinal cord
  • CSF production, flow and absorption
  • ciliated - facilitates flow
  • allow solute exchange between nervous tissue and CSF
17
Q

Describe the choroid plexus

A
  • frond-like projections
  • formed from modified ependymal cells, villa form around network of capillaries, large surface area
  • main site CSF production by plasma filtration
  • tight gap junctions between cells form blood-CSF barrier