SFP: CNS neurons and neuroglia Flashcards
Describe the differences between gray matter and white matter
White matter is largely axons, while grey matter is mostly cells
Describe the location of grey and white matter in the spinal cord and brain
In the cord, white matter is on the outside and grey matter is on the inside. In the brain, grey matter is on the outside and white Matter is on the inside
Describe nuclei
clusters of neurons in the CNS
describe ganglia
clusters of neurons in the PNS
describe cortex
layers of cell bodies (grey matter) found on the outside of the brain
describe nerves
bundle of axons in the PNS
describe tracts
bundles of axons in the CNS
describe the function of neurons
signal processing and communication cells in the nervous system
what are nissl bodies?
ribosomes in neurons
do neurons undergo mitosis?
no!
what are the major structural components of a neuron?
dendrites, cell body, axon, synaptic bouton
what is the functional role of dendrites?
they receive input from neighboring neurons
describe dendtritic spines
small protrusions on dendrites that contain receptors for neurotransmitters and are associated with synaptic contacts.
what is associated with more dendritic spines
having more dendritic spines is associated with greater synaptic capacity and efficacy
describe the cell body
where metabolic support occurs; lots of mitochondria and nissl bodies
describe axons
this is where action potentials take place; have microtubules to move neurotransmitters. Neurons have only one axon, but it can branch
describe axon terminals (synaptic boutons)
Site of signal transfer from one neuron to the next; they have vesicles containing neurotransmitter
describe the release of neurotransmitters from axon terminals
The presynaptic neuron has vesicles containing neurotransmitters. The cascade of events following an action potential causes the release of these neurotransmitters into the synaptic cleft. The neurotransmitters then bind to receptors on the postsynaptic neuron.
describe anterograde axonal transport
Transport away from the cell body, which is very common for neurotransmitters. the process uses the microtubule kinesin
describe retrograde axonal transport
Transport from the axon terminal toward the cell body. This is very common with growth factors so they can aid with transcription/translation in the cell body. the process uses the microtubule dynein
Differentiate between afferent and efferent neurons
Afferent move stimuli towards the CNS, while efferent move stimuli away from the CNS
Name the types of neuroglia and the basic function of neuroglia.
They are support cells, and heavily outweigh neurons in number. They big types are astrocytes, microglia, oligodendrocytes, and ependymal cells
Describe the structural and functional characteristics of astrocytes
They maintain the environment around neurons; gather up excess glutamate, play a role in the blood-brain barrier, and are bound by tight junctions. They also take up ions from the extra cellular fluid
describe oligodendrocytes
They are important for making myelin and providing support. One oligodendrocytes can myelinate many axons
describe ependymal cells
They line the ventricles of the brain and regulate CSF. These are bound by tight junctions. They contain cilia to help circulate CSF and are found at the choroid plexus to form CSF
describe microglia
The macrophages of the brain. They respond to trauma, infection, and other injury. They activate and become motile and recruit other cells. With neurodegeneration, we see a lot of activated microglia
which glial cells release ROS and cytokines?
microglia
what do nissl stains show? are there cell bodies visible?
gray matter; cell bodies present
what do myelin stains show? are there cell bodies visible?
white matter; no cell bodies present
describe convergence and divergence
convergence: single neuron can receive input from many sources.
divergence: one axon can branch to impact cells in different locations.
convergence and divergence are seen in what kinds of neurons?
motor; sensory
