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61 Cards in this Set
- Front
- Back
What are 3 main functions of the NS
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1. monitor changes in internal and external exvironment thorough sensory input
2. Process and interpret the sensory input and decides how to respond (integration) 3. Causes a resonpse (motor output) |
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What are the main components of CNS
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the brain and spinal cord
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What is main function of CNS
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is the interegating and control center
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What are the main compontes of teh PNS
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Cranial nerves and spinal nerves
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What is the main function of PNS
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serves as the communcaiton lines between teh CNS and the rest of the body
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What are the 2 functional subdivision of the PNS
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sensory or AFFERNT division and Motor (EFFERENT) division
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What composes the sensory or afferent division and the function
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Somatic (body) carry impules to skin to CNS
Visceral carry impules from organ to the CNS |
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What composes the motor or efferent division
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of the PNS transmits impulses FROM the CNS to effector organs
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What are 2 main parts of the MOTOR division
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ANS and the Somatic Nervous system
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WHat is the somatic nervous system
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conducts impulses from the CNS to skeletal muscles and is VOLUNTARY
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What composes the Aoutonmic Nervous Systems (ANS)
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Involuntary (VISERAL) motor
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What is function of ANS
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conduts impulese from CNS to cardiaci, smooth muscles,and glands
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What are 2 functional subdivision of ANS
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Sympathetic and parasympathetic nervous sytem
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Sympathetic (fight or flight) what is function of parasympathetic
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conserves energy, and NON-emergy function
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What are special characteristic of neurons
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1. extreme longevity
2. amitotic (cannot divide) 3. HIGH metabolic rate 4. conduct nerve impulses |
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The brian and spinal cord contain both CELL bodies and processes, what mainly composes PNS
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consists of axons (nerve processes)
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What are bundles of neurons in CNS called versus PNS
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Bundles in CNS called TRACTS
Bundles in PNS called nerves |
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What are dendrites
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short branches, and main input regions
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Each neruon has a SINGLE axon, what does it do
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generate NERVE impulse and transmits it
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What are axon collateral
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extend from teh axon at more of less right angles
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What are the functional classes of neurons
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1. Afferent Neurons
2. Efferent Neurons 3. Interneurons |
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Virtually of Afferent Neurons in PNS are unipolar explain
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2 axons and cell body between with no axons
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What is an interneuron, and where are mainly located (MOST PREVALENT)
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shuttle signals through the CNS--located in CNS
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What a efferent neurons
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motor neurons, conduct impulses from interneurons to sensory organ
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THe nervous system is made of 2 principal cells
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Neurons and Glial cells
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What are 4 glial cells in CNS
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Astrocytes, Microglia, Ependymal, and Oligodendrocytes
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What are the functions of star shapped astrocytes
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cover nearby cappilaries and make exchanges of nutrients, pick up NTs and BBB
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What are Microglia cells
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like macrophages clean up debris
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What are Ependymal cells
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lines cavites of brain and spinal cord and help move CSF
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What are 2 myelin forming cells
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Oligodendryocytes (CNS)
Schwann Cells (PNS) |
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WHat is anterograde movment
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movement of the electrical signal towards the AXON terminal
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What is retograde movement
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movenet in the oppostiste direction towards cell body
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What is benefit of retrograde
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recycling
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What is negative of retrograde
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transport of viruses (rabies, polio, herpes simlex, adn tetanus
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What is mechanism of anterograde movement
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The kinesin protein with a NT binds to the microtubles and moves down until it discharges NT
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What is mechanism of retrograde movement
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THe protein DYNEIN binds a recycled NT and then binds to microtubles which shuttle to cell body
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Can nerves in the CNS be regenerated AND WHY, what can
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NOT CNS, THEIR SUPPORTING CELLS PREVENT, oligodendrocytes die and fail to guide fiber regrowth--regeneration--ONLY PNS
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What is required for regeneration of a nerve in PNS
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ONLY AXON can regenerate--cell body cannot
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Where do sensory impulses enter spinal cord, as and 1st synpase on
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spinal nerves eneter the dorsal root and synpase on DRG, which then continue on as white matter or synpase on gray matter
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What is the resting membran protential
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-70 mV
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What is the role of the Na/K+ ATPase pump
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is ALWAYS ON...maintains the concentration gradients
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What is the role of K+
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K+ has leaky channel (always open) so it going down its concentration gradient until and estabilish the -70mV
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What does K+ establish
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the RESTING MEMBRANE potential
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What is the ECF concentration of Na+ and K+
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150 MEQ NA
5 MEQ K+ |
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What is the ICF concentration of Na+ and K+
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150+ K
15 NA |
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WHat are action potentials
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Large (100mV) and breif changes in membrane potentials--all or none
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Leaking channels are always open, what are types of gated channels (open and close
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1. Ligand-gates
2. Voltage gated 3. Mehcanicall gated |
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WHat type of channels are assoicated with a change in membrane potential
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voltage-gates channels
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You have an action potential that depolzarizes cells, what happens
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OPEN the Na+, rush in making the cell more postive until is reaches theshold (-55)
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What happens once you reach theshold
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then more and more Na+ open till all are open
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What happens after membrane overshoot 0
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then have inactivation of Na+ channels, and SLOW open of K+ channels which rush out and repolarize the mebrane
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What happens after repolarization
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Hyperpolarization, but the K+ channels are slow to close
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If ALL action potential are the same--ALL or NONE, then how do increse the intensity of a signal
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INCREASED FREQUENCY
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How does the abolute refactory period ensure that the action potient is ALL or NONE
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cannot stimulate another action potential as Na+ are inactivated rather than closed
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What is the relative refactory period
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Na+ are closed, and repolarzation is occuring requries a stong stimulus for another action potential to occur
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What determines the conduction velcotiy of an action potential
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1. Fiber diameter-the larger the faster
2. Myline--triggers saltarory doncution |
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What is saltaroy conduction
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current jumps between myline at nodes of Ranvier which have high Na+ channels
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What are EPSP
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signals that depolarize membrane--need mutiple to reach theshodl
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What is temporal sumation
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when one or more presyntatic neurons tramsits impules to help reach theshol several times in a row
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What is spatial summation
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when the post-synaptic is stimulated AT the SAME TIME mutiple times
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What are IPSP
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realse of NT--that move the mebrane farther from an AP
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