Term
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Definition
| structural and functional units of the nervous system that are specialized to react to physical and chemical changes in their surroundings; nerve cells |
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Definition
| electrochemical changes that transmit information |
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Definition
| electrochemical changes that transmit information |
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| portion of the nerve cell that inculeds a cytoplasmic mass and a nucleus, and from which nerve fibers extend |
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Definition
| process of a neuron that recieves input from other neurons |
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Definition
| a nerve fiber; conducts a nerve impulse away from the neuron cell body |
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Definition
| bundles of axons in the peripheral nervous system |
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Definition
| specialized cells of the nervous system that produce myelin, communicate between cells, and maintain the ionic environment |
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Term
| central nervous system (CNS) |
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Definition
| the brain and spinal cord |
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Term
| peripheral nervous system (PNS) |
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Definition
| portions of the nervous system outside the central nervous system |
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Definition
| specialized structure associated with the peripheral end of a sensory neuron specifc to detecting a particular sensation and triggering a nerve impulse in response, which is transmitted to the central nervous system |
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Definition
| muclses that are outside the nervous systme that contract and glands that secrete when stimulated by nerve impulses |
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Definition
| motor pathways of the peripheral nervous system that lead to the skin and skeletal muscles - under concious control |
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| portion of nervous system that controls the viscera (organs) - unconcious control |
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| fatty material that forms a sheathlike covering around some axons |
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Definition
| neuroglial cell that supports neurons and phagocytizes |
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Definition
| type of neuroglial cell that forms myelin (only in the CNS) |
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Definition
| type of neuroglial cell that connects neurons to blood vessels |
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Definition
| a membrane composed of neuroglial cells that line the ventricles of the brain |
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Definition
| type of neuroglial cell that surrounds an axon of a peripheral neuron, forming the neurilemma sheath and myelin |
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Definition
| a fine, cytoplasmic threads that extends from the cell body into the process of a neuron |
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Definition
| sheath formed from Schwann cells on the outside of some axons |
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Definition
| narrow gaps between Schwann cells |
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Definition
| a sensitive part of an axon where a nerve impulse originates |
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Term
| ganglia (singular - ganglion) |
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Definition
| a mass of neuron cell bodies, usually outside the central nervous system |
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Definition
| a neuron that transmits an impluse from a receptor to the central nervous system |
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Definition
| a neuron between a sensory neuron and a motor neuron that lie entirely in the CNS |
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Definition
| a neuron that transmits impulses from the central nervous system to an effector |
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Definition
| the functional connection between the axon of a neuron and the dedrite or cell body of another neuron or the mebrane of another cell type |
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Definition
| chemical that an axon end secretes on an effector (muslce or gland) or another neuron |
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Term
| excitatory neurotransmitter |
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Definition
| increases postynaptic membrane permeability, which may trigger a nerve impulse |
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Term
| inhibitory neurotransmitter |
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Definition
| decreases the permeability of the postsynaptic membrane, lessening the chance that a nerve impulse will occur |
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Term
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Definition
| groups of neurons that make hundreds of synaptic connections with each other an dwork together to perform a common function |
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Term
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Definition
| subthreshold stimulation of a neuron that increases responsiveness to further stimulation |
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Definition
| impulses from one neuron can stimulate two or more neurons - can amplify an impulse spreading it to more neurons in the pool |
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Definition
| any single neuron in a neuronal pool receives impluses from two or more incoming axons - have a summative effects |
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Definition
| also called sensory fibers; neuron processes that bring sensory information to the CNS |
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Definition
| also called motor fibers - carry impulses from the CNS to effectors |
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Definition
| a nerve that consists of sensory neuron axons |
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Definition
| a nerve that consists of motor neuron axons |
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Definition
| nerve that includes both sensory and motor neuron fibers |
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Term
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Definition
| a nerve pathway, consisting of a sensory neuron, interneuron, and motor neuron, that forms the structural and functional bases for a reflex |
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Definition
| a rapid, automatic response to a stimulus |
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