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31 Cards in this Set
- Front
- Back
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Neuron=nerve cell |
primary functional and anatomic unit of the nervous system -sensory -motor -interneurons |
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Nuceli |
Groups of neuron cell bodies within the CNS |
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Ganglia |
groups of neuron cells bodies within of PNS |
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Basic Functions of the Neuron |
designed to: Receive information (from afferent tracts) Process the information (integration in cell body) Generate an output-transfer information to another neuron or effect (efferent tract) |
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What kind of interactions do neuron transmissions partake in? |
electrical and chemical interactions |
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How do neurons transmit information about their activity? |
Through neurotransmitters....via the release of chemicals |
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Soma or cell body |
contains the nucleus and cellular organelles critical for protein synthesis |
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Dendrites |
branchlike extensions from the soma, conducts impulses toward the cell body, many dendrites per neuron. These are AFFERENT processes |
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Axon |
single fiber extending to other parts of the nervous system or to a muscle or gland. EFFERENT fiber |
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Presynaptic terminal or bouton |
fingerlike projections at the terminal end of axon |
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Structural Morphology of Neurons: Unipolar |
Unipolar: A single short process divides into two. Cell bodies in dorsal root ganglia. (sensory only) |
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Bipolar |
One axon and one dendrite coming off the soma Limited to the visual, auditory and vestibular pathways |
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Multipolar |
3 or more processes extending from cell body. Comprise the majority of neurons in the CNS. |
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Where do axons being at? |
Begin at the axon hillock...from microns to meters...maintained by the soma:axonal transport |
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Anterograde Axonal transport |
-Nutrients are carried forward to sustain the axon -Used in the creation and transport of neurotransmitters |
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Axonal Transport: Retrograde |
Return of waste products from axon to the soma the route by which toxins....tetanus, herpes, simplex, rabies and polio are transported into the CNS from the periphery |
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Supporting Cells: Glia- GLUE |
provides structural and metabolic support for neurons, transmits information characterized by size and function |
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Macroglia |
Large glia cells Astrocytes Oligodendrocytes Schwann Cells
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Microglia (CNS) |
small glia cells Phagocytics or scavenger role |
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Ependymal (CNS) |
Line the ventricle of the brain and central canal of spinal cord |
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Astrocytes |
Star shaped cells found throughout the CNS Plays a role in neuron signaling, maintenance of normal signaling cleans up chemical transmitter from the synaptic cleft |
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Which glial cell is the most common to become malignant? |
Astrocytes |
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Myelin Sheath |
White glistening, fatty substance encasing nerve fibers (axons) Encases many but not all nerve fibers Enhances the speed of the conduction of impulses |
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Nodes of Ranvier |
patches of unmyelinated axon where nerve signals jump from one node to the next |
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What does conduction speed depend on? |
Diameter of axon and myelination |
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Unmyelinated small-diameter axons |
Type IV 4 motor nerves or type C sensory nerves have an impulse transmission of 0.5 to 2 m/s |
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Myelinated large-diameter nerves |
type I or A-alpha propagate information at 80-120m/s |
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Oligodendrocytes |
produce myelin around axons in the central nervous system |
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Schwann cells |
produce myelin around axons in the peripheral nervous system |
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