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24 Cards in this Set
- Front
- Back
What are the two classification methods?
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1. Functional classification
2. Structural classification |
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How are neurons functionally classified?
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-Sensory/afferent: APs towards CNS
-Motor/efferent: APs away from CNS -Interneurons/association: within CNS from one neuron to another |
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How are neurons structurally classified?
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-Multipolar: many dendrites, single axon, most neurons in the CNS and motor neurons
-Bipolar: one dendrite, one axon, sensory organs (eyes) -Unipolar (pseudo-unipolar): single process extending from cell body - divides into 2 branches - part extending into periphery had dendrite-like sensory receptors |
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What is the function of a vesicle in axonal transport?
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-To release neurotransmitters in the pre-synaptic terminal that either stimulate or inhibit post-synaptic cell
-To move up and down the axon transporting neurotransmitters |
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What are the neuroglia?
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-Nervous tissue "glue"
-Support and protect nerve cells -Smaller cells but are very numerous -Account for over half the weight of the brain |
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What are the 4 types of neuroglia? (supporting cells of the CNS)
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1. Astrocytes
2. Ependymal Cells 3. Microglia 4. Oligodendrocytes |
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What are the functions of astrocytes? What are they?
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-Largest and most numerous of glial cells (star-shaped)
-Cover surfaces of blood vessels, neurons and pia mater -Release chemicals to form tight junctions between endothelial cells of capillaries -"Blood brain barrier": protect against toxic substances -Helps maintain a chemical environment |
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What are the functions of ependymal cells? What are they?
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-Line the ventricles of the brain and central canal of spinal cord
-Helps form the choroid plexus and patches form cilia -Cilia moves CSF that is produces through ventricles |
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What are the functions of microglia? What are they?
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-Specialized macrophages in the CNS
-Phagocytic: inflammation (protective function) -Can engulf dead tissues, microorganisms, foreign substances, and break them down and destroy them |
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What are the functions of oligodendrocytes? What are they?
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-Smaller and fewer processes
-Cytoplasmic extensions: surround axons -Form myelin sheaths around portions of several axons |
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What are the supporting cells of the PNS?
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1. Schwann cells
2. Satellite cells |
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What are the functions of Schwann cells? What are they?
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-Wrap around axons
-Forms myelin sheath around portion of only one axon -Forms lipid layer that allows action potentials to be conducted at a faster rate |
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What are the functions of satellite cells? What are they?
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-Surround neuron cell bodies in ganglia
-Provides nutrients to cell body and support |
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What is the function of myelin?
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To protect and insulate axons from each other
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What's the difference between myelinated and unmyelinated axons?
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Myelinated: axons conduct signals more rapidly
Unmyelinated: only wraps around axons a single time and doesn't provide as much insulation or protection and has multiple axons |
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What is white matter?
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-Myelinated axons
-Nerve tracts propagate action potentials from one area in the CNS to another |
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What is gray matter?
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-Unmyelinated axons, cell bodies, dendrites, neuroglia
-integrative functions |
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Where is gray and white matter found... in the brain? In the spinal cord?
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In the brain, gray is outer, white is inner
In the spinal cord, white is outer, gray is inner |
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What are dendrites?
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-Create the synapse
-Electrical impulses are received from other neurons -Cytoplasmic extensions |
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What's the axon hillock?
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-Where the axon meets the soma (cell body)
-Initial segment -Action potentials are started at trigger zone (axon hillock) |
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What's the axon?
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-Start=initial segment
-End=presynaptic terminal -Carries nerve signals away from soma |
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What is a presynaptic terminal?
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Contains neurotransmitters that cross the synaptic cleft
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What is a node of ranvier?
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Gaps between Schwann cells where there's no myelin sheath
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What is a collateral axon?
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Sends signals to other structures
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