BIOL371 MIDTERM EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS GRADED A++
Olygodendrocytes
- create layers of myelin around some axons
- in CNS
- proliferate when we learn
Schwann cells
- create myelin around one axon
- in PNS
- proliferate after PNS injury
- assist with axonal regrowth
Microglia
- primary immune cells of CNS, but not the brain's immune system
- specialized macrophage-related cells that reside within CNS
- non immune functions: guide growth of neurons (and glia) and prune neurite/synapse
Immune system
real myeloid and lymphoid WBC's from outside enter the CNS
Astrocytes
1. possess cell processes that interact with synapses or blood vessels and BBB
2. buffer extracellular ion conc. (K+)
3. provide nutrient/remove metabolites to neurons
, 4. recycle neurotransmitters after release
5. promote/regulate neuron and synapse growth
Convergence
property of post-synaptic neuron, inputs converge onto it
Divergence
pre synaptic neuron, its outputs diverge to multiple synaptic partners
Sensory neurons
- dendrite joins the axon not the soma (psuedo-unipolar)
- somata outside CNS (DRG)
- axon enters spinal cord on the dorsal side
Motor neuron
- one axon, many dendrites (multipolar)
- soma and dendrites in ventral grey matter
- axon leaves spinal cord via ventral root and travels directly to skeletal muscle cells
IPSP
most have a reversal potential at Ecl or RMP
Na+ gates
- m gate open quickly: causes a positive feedback loop where it causes more Na+
conductances to open
- h-gate closes V-gated Na+ conductances even at depolarized voltages; will not fully
deactivate until Vm is repolarized
K+ gate
- n gate opens slowly: causes negative feedback which shuts off conductances
COMPLETE SOLUTIONS GRADED A++
Olygodendrocytes
- create layers of myelin around some axons
- in CNS
- proliferate when we learn
Schwann cells
- create myelin around one axon
- in PNS
- proliferate after PNS injury
- assist with axonal regrowth
Microglia
- primary immune cells of CNS, but not the brain's immune system
- specialized macrophage-related cells that reside within CNS
- non immune functions: guide growth of neurons (and glia) and prune neurite/synapse
Immune system
real myeloid and lymphoid WBC's from outside enter the CNS
Astrocytes
1. possess cell processes that interact with synapses or blood vessels and BBB
2. buffer extracellular ion conc. (K+)
3. provide nutrient/remove metabolites to neurons
, 4. recycle neurotransmitters after release
5. promote/regulate neuron and synapse growth
Convergence
property of post-synaptic neuron, inputs converge onto it
Divergence
pre synaptic neuron, its outputs diverge to multiple synaptic partners
Sensory neurons
- dendrite joins the axon not the soma (psuedo-unipolar)
- somata outside CNS (DRG)
- axon enters spinal cord on the dorsal side
Motor neuron
- one axon, many dendrites (multipolar)
- soma and dendrites in ventral grey matter
- axon leaves spinal cord via ventral root and travels directly to skeletal muscle cells
IPSP
most have a reversal potential at Ecl or RMP
Na+ gates
- m gate open quickly: causes a positive feedback loop where it causes more Na+
conductances to open
- h-gate closes V-gated Na+ conductances even at depolarized voltages; will not fully
deactivate until Vm is repolarized
K+ gate
- n gate opens slowly: causes negative feedback which shuts off conductances
