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Details Title: Nervous System Description: Nervous System Total Flash Cards: 36 Created: 11/28/2005 10:30:14	To study from this set of flash cards, or to create your own your own study flash cards, register HERE. If you are already a registered user, CLICK HERE.
Cards Term Astrocytes Definition Support; Guide migration of young neurons; Attaches neuron to food source; Anchors neurons Term Oligodendrocytes Definition Wraps CNS nerve fibers; Forms myelin sheaths in CNS Term Schwann Cells Definition Surrounds Fibers of PNS; Forms myelin sheaths in PNS Term Microglia Cells Definition Phagocytes involved in health Term Passive or Leakage Channels Definition Always open; Potassium always leaks out of cells Term Chemically Gated Channels Definition Needs the binding of something to open Term Voltage Gated Channels Definition Once open, everything that takes place depends on voltage (changes in membrane potential) Term Mechanically Gated Channels Definition Responds to mechanical stimulus (auditory system) Term What is the functional role of nervous system "signals"? Definition Communication for receiving, intergrating, and sending information Term What are graded potentials? Definition Short lived, local changes in membrane potential that can either be repolarizations or hyperpolarizations. Occurs around cell body and dendrites. Can lead to action potential. Term True or False: Action potentials are breief reversals of membrane potential; are the principle means of neural communication; and maintain their strength over distance Definition True Term What is the synapse? Definition A junctin that mediates information transfer from one neuron to the next or from a neuron to an effector cell Term WHat are IPSP's? How do they work? Definition Inhibitory postsynaptic potentials induce hyperpolarization and inhibits action potential. Term What is presynaptic inhibition? Definition Occurs when the release of excitatory neurotransmitter by one neuron is inhibited by the activity of another neuron via axoacnonix synapnse. Term What are the major class of NT's in the CNS? Definition Amino Acids Term Which of the following is not a neurontransmitter? a. NO b. ATP c. Dopamine d. testosterone Definition d. testosterone Term Which of the following NT's are both excitatory and inhibitory depending on its receptor type? a. ACh b. ATP c. Dopamine d. Testosterone Definition A, B, and C (ACH, ATP, Dopamine) Term True or False: Acetylcholine is inhibitory to skeletal muscles and excitory to cardiac muscle. Definition False Term How is it that norepinephrine (NE) can inhibit smooth muscle action in airways, yet stimulate contractions in smooth muscle everywhere else in the body? Definition NE is both excitatory and inhibitory depending on the receptors. Term Define a direct receptor mechanism Definition NT's that open ion channels Term Define indirect receptor mechanism. Definition NT's that act trhough second messengers. Term What are the types of input processing that occur? Definition Serial Processing (input moving along a single pathway) & Parallel Processing (information on several pathways) Term Anterograede Definition Movement towar axon terminals Term Retrograde Definition Movement away from axon terminals. Term White Matter Definition White substance of the central nervous system; Myelinated nerve fibers Term Gray Matter Definition Greay area of the central nervous system; contains cell bodies and unmyelinated fibers of neurons Term Sensory (afferent) neurons Definition Nerve cell that carries impulses toward the central enrvous system; initiates nerve impulses following receptor stimulation Term Motor (efferent) neurons Definition Nerves that carry impulses leaving the brain and spinal cord, and destined for effectors Term Interneurons Definition Lie between motor and sensory neurons in neutral pathways and shuttle signals through CNS pathways where intergration occurs Term Postsnynaptic Membrane Definition The surface of the cell on the opposite side of the sunapse from the synaptic terminal of the stimulating neuron that contains receptor proteins and degradative enzymes for the NT's Term Synaptic Cleft Definition Fluid filled space at a synapse Term Serial Processing Definition One neuron stimulates the next, which stimulates the next, and so on, eventually causing a specific, anticipated response Term Parallel Processing Definition Inputs are segregated into many pathways, and information delivered by each pathway is dealt with simultaneously by different parts of the neural circuitry Term Presynaptic inhibition Definition Occurs when the release of excitory NT's by one neuron is inhibited by the activity of another neuron via axoaxonic synapse Term Neuromodulation Definition Occurs when a NT acts via slow changes in target cell metabolisim or when chemicals other than NT's modify neuronal activity Term Synaptic Potentiation Definition Repeated of continous use of a synapse which ehances the presynaptic neuron's ability to excite the postsynaptic neuron, producing larger than expected postynaptic potentials