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18 Cards in this Set
- Front
- Back
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• What 2 types of signals do the nervous system use to communicate?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
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electrical and chemical signals
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• What are the 3 overlapping functions of the NS?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> |
1. monitor changes both inside and out the body = sensory input (stimuli) - via millions of sensory receptors 2. Integration= processes & interprets sensory input & decides what action to take 3. Cause a response or action (motor output) by activating affector organs |
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o What are the 2 main divisions of theNS? What structures make up theCNS? The PNS?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> |
-Cranial and Peripheral Nervous Systems -CNS: brain and spinal cord -PNS: nerves |
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o What are the 2 subdivisions of thePNS, and what do their nerve fibers (axons) do?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> |
-Cranial nerves= carry impulses to/from brain -Spinal nerves= carry impulses to/from spinal cord |
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o What are the 2 subdivisions of theMotor/Efferent division, and what do their nerve fibers do?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> |
- multipolar in structure - transmit impulses from CNS to effector organs(muscles,organs,glands) to produce a response |
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• List the different types of neuroglia, whether they are found inthe CNS or the PNS, and their major functions.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
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CNS -Astrocytes: most abundant, to transport substances between neurons and blood vessels -Microglia: touch and monitor nerons -Ependyma: allow substances to move back and fourth bestween the CSF & tissue fluid of the brain -Oligodendrocytes: produce myelin in the CNS PNS -Satellite cells: surround neuron cell bodies -Schwann cells: produce myelin in the PNS
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<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> • Describe a neuron, its parts, and the direction in which nerveimpulses are transmitted between neurons.
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-Neuron:Structural/functional units of NS, large specialized cells that conduct electrical impulses, extreme longevity(>100yrs), amitotic(do not divide), high metabolic rate(requires continuous supply of oxygen &glucose) -from cell body to axon |
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• Describe the myelin sheath and how its presence affects the speedof nerve impulse conduction. How does saltatory conduction differ fromcontinuous conduction? How does the diameter of an axon affect conductionspeed?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
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-composed of eitherschwann cells or oligodendrocytes, acts as an electrical insulator to resist or slow the flow of electrical current -Sc:electrical impulses aren't hindered at the Nodes and can flow; impulses appear to "jump over" the myelin sheaths -CC: in nonmyelinated axons, impulses travel down the entire surface of the axon -The thicker the axon, the faster the nereve impulse. |
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• Whatis multiple sclerosis? What are somesymptoms? What is the root cause: what does the word “sclerosis” mean?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> |
-MS: autoimmune disease in which the body attacks the myelin sheaths in the CNS. -Symptoms: 1. visual disturbances; blindness 2. weakness, clumsiness, paralysis 3. speech disturbances 4. urinary incontinence -Hardened lesions |
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• What does white matter consist of, and why does it lookwhite? How about gray matter?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> |
- regions of CNS w/ dense collections of myelinated axons - regions of CNS consisting of neuron cell bodies and nonmyelinated axons |
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• How are neurons classified based on structure? Describe/draw each type. How are neurons classified based onfunction? Describe each type.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> |
-Multipolar: many dendrites; 1 axon; most common -Bipolar: 1 dendrite on one side and 1 axon on the other side. Rare, parts of eye, nose, & ear -Unipolar: one process w/ 2 branches that function as one axon |
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• Describe the events from start to finish leading to an actionpotential (nerve impulse). Be sure touse these terms: resting potential (membrane potential), depolarization,threshold, action potential, repolarization. Describe the movements of Na+ and K+ during these steps.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> |
*on sheet
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• Do “depolarization” and “threshold” mean the same thing? If not, what is the difference?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> |
-No -Depolarization: cell membrane becomes less negative than the resting potential (loss of the state polarity) -Threshold: "the magic #"; the level of depolarization at which an action potential(nerve impulse) is guaranteed to happen (around -55mv) |
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• What is the refractory period? What is the all-or-nothing response?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> |
-Period following stimulation during which the nuron will not respond to another stimulus. Occurs during the time when the neuron is reestablishing the resting potentials. Limits how many AP's can be generated in a given period of time
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• What’sthe difference between electrical synapses and chemical synapses? Which type isthe majority in the body?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> |
-E: gap junctions connect the cytoplasm of adjacent neurons so they exchange ions, allowing a very rapidtransmission. Abundant in developing embryo. Sparse in adults. Communication can go both directions. -C: the nerev impulse in the presynaptic neuron is electrical, in the cleft it is chemical, and in the postsynaptic cell it is changed back to electrical. |
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How canneurotransmitters affect the postsynaptic cell (why are neurotransmitterscalled the language of the nervous system)?
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1. If excitatory, they will cause action potentials in the postsynaptic cell (cause depolarization) 2. If inhibitory, they will cause hyperpolarization in the postsynaptic cell |
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• Why is it important that no excessneurotransmitters hang around in the cleft?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> |
there will be constant signals sent to the postsynaptic cell
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• What are the 3 ways to terminate theeffects of neurotransmitters?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
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1. reuptake of NT by the axon terminal 2. degradation by enzymes 3. diffusion away from the cleft |
