Supporting Cells of the Nervous System Flashcards
Ciliated cells that line the ventricles of the brain and the central canal of the spinal cord
Ependymal cells
These cells contribute to the formation and circulation of cerebrospinal fluid
Ependymal cells
These cells play a role in directing cell migration during brain development
Ependymal cells
Phagocytes that engulf debris
Microglia
These cells are also involved in remodelling of synaptic connections
Microglia
These cells can migrate from brain to blood
Microglia
What type of cell are all of the following:
- astrocytes
- oligodendrocytes
- schwann cells
- capsular cells
Macroglia
The most numerous cells in the nervous system
Astrocytes
These cells undergo alterations in response to many insults to the CNS and are highly susceptible to the formation of neoplasms
Astrocytes
These cells control electrolyte balance in the CNS (particularly extracellular K+)
Astrocytes
These cells produce neurotrophins necessary for neuronal survival
Astrocytes
Name transmitters taken up by astrocytes
Glutamate
GABA
Which cell supplies glutamine for the synthesis of neurotransmitter glutamate by neurones?
Astrocytes
These cells regulate the ‘tightness’ of the blood brain barrier
Astrocytes
These cells produce neurotrophic factors (e.g. nerve growth factor) which is important for repair of damaged axons in the CNS
Oligodendrocytes
Loss of this type of cell contributes to demyelinating disorder MS
Oligodendrocytes
Why does loss of myelin cause a failure of salutatory conduction?
There are no voltage-activated sodium channels in the area of axon previously engulfed by the oligodendrocyte process
Difference between oligodendrocytes and Schwann cells?
Oligodendroctyes - CNS
Schwann cells - PNS
Oligodendrocytes can envelope lots of axons (40-50 if the myelin sheath is thin). Each Schwann cells envelops only a short segment of one axon)
If a Schwann cell only envelops a short segment of one axon, how do they envelop an entire axon?
A chain of Schwann cells are required to myelinate an entire axon
These cells are extremely important in the regeneration of transected aons
Schwann cells
-stimulated schwann cells proliferate to form a ‘tube’ into which growth sprouts from the proximal end of the cut axon enter and ultimately re-innervate the previously de-innervated target
Name a disease whereby the peripheral neurones become demyelinated
Guillian-Barre syndrome
These are glial elements that surround the neuronal bodies in sensory and autonomic ganglia
Capsular (or satellite) cells
These cells separate ganglion cell bodies in dorsal root ganglion
Capsular (satellite) cells
