Neurons, Glia, CNS Histology Flashcards
Where can synapses occur on a neuron?
Axospinous: excitatory ONLY
Axodendritic: excitatory or inhibitory
Axosomatic: excitatory or inhibitory
Axoaxonic: excitatory or inhibitory
What is anterograde axonal transport?
Carries substances (mitochondria, membrane proteins, synaptic vesicles, neurotransmitters, cytosolic and cytoskeletal proteins) produced by neuron to neuronal synapse via kinesins (ATPase) along microtubules. Moves away from cell body; -end to +end of microtubule
What is retrograde axonal transport?
Allows growth factors to be transported from axon terminal to neuron cell body via dyenins along microtubules in the +end to -end direction.
Movement of recycled components from axon terminal (ex: endosomes and damaged mitochondria) to neuron cell body.
Via what mechanism to viruses and toxins enter neuronal cell bodies?
Retrograde axonal transport - they are uptaken at the axon terminal and moved to the neuronal cell body via dyneins.
What is the function of astrocytes?
- Provide structural and functional support to neurons (maintaining pH, lower extracellular K+, secrete growth factors and cytokines, remove glutamate from synapses to prevent neurotoxicity, help neuronal metabolism by storing some glycogen)
- Respond to injury when neurons are destroyed in brain by proliferating and filling spaces
- Insulate CNS from other tissues
Describe an astrocyte’s response to neuron damage in the brain.
What is an astrocytic scar?
When injury to the brain results in neuron damage - astrocytes proliferate and fill the space that was previously taken up by neurons and then their debris after destruction.
The clump of astrocytes is an astrocytic scar.
Why do many CNS tumors have astrocytic origin?
Because they easily proliferate in the brain and they can escape the control of cell division.
Where can synapses occur on a neuron?
Axospinous: excitatory ONLY
Axodendritic: excitatory or inhibitory
Axosomatic: excitatory or inhibitory
Axoaxonic: excitatory or inhibitory
What is anterograde axonal transport?
Carries substances (mitochondria, membrane proteins, synaptic vesicles, neurotransmitters, cytosolic and cytoskeletal proteins) produced by neuron to neuronal synapse via kinesins (ATPase) along microtubules. Moves away from cell body; -end to +end of microtubule
What is retrograde axonal transport?
Allows growth factors to be transported from axon terminal to neuron cell body via dyenins along microtubules in the +end to -end direction.
Movement of recycled components from axon terminal (ex: endosomes and damaged mitochondria) to neuron cell body.
Via what mechanism to viruses and toxins enter neuronal cell bodies?
Retrograde axonal transport - they are uptaken at the axon terminal and moved to the neuronal cell body via dyneins.
What is the function of astrocytes?
- Provide structural and functional support to neurons (maintaining pH, lower extracellular K+, secrete growth factors and cytokines, remove glutamate from synapses to prevent neurotoxicity, help neuronal metabolism by storing some glycogen)
- Respond to injury when neurons are destroyed in brain by proliferating and filling spaces
- Insulate CNS from other tissues
Describe an astrocyte’s response to neuron damage in the brain.
What is an astrocytic scar?
When injury to the brain results in neuron damage - astrocytes proliferate and fill the space that was previously taken up by neurons and then their debris after destruction.
The clump of astrocytes is an astrocytic scar.
Why do many CNS tumors have astrocytic origin?
Because they easily proliferate in the brain and they can escape the control of cell division.
