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67 Cards in this Set
- Front
- Back
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Nervous System _________ and _________ other body systems using _________ & _________ impulses |
Nervous System Regulates and coordinates other body systems using electrical & chemical impulses |
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Central nervous system (CNS) consists of _________ and _________ |
brain and spinal cord |
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Peripheral nervous system (PNS): |
motor and sensory nerves |
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Membrane potential: _________ of charge _________ across a _________ measured in _________ _________ of cell usu. relatively more_________ than _________ |
Membrane potential: magnitude of charge difference across a membrane
measured in voltage[usu millivolts (mV)] inside of cell usu. relatively more (-) than outside |
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-Resting membrane potential --> membrane potential for cells in the _________ and for _________ /_________ cells that aren’t being _________ |
Resting membrane potential--> membrane potential for cells in the body and for neurons/muscle cells that aren’t being stimulated
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-Causes of Resting Membrane Potential a) Difference in ______ /_________ of ions b) Difference in permeability of _________ membrane to ______, ______ & other ions c) Presence of fixed _________ inside cell -->large neg.charged ions that..... |
a) Difference in distribution/concentration of ions- b) Difference in permeability of plasma membrane to Na+, K+ & other ions-plasma more permeable to K+ than Na+ c) Presence of fixed anions inside cell -->large neg.charged ions that can’t get out-proteins, phosphates of ATP, nucleic acids, etc. |
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What’s value of the resting membrane potential for a cell? |
mmm |
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-For each ion, we need to consider: ______ . gradient ______ of membrane to ion |
-conc. gradient -permeability of membrane to ion |
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-Neuron- basic structural & functional unit of _________ _________ -respond to _________ , conduct _________ , release _________ |
Neuron- basic structural & functional unit of nervous system -respond to stimuli, conduct electrochemicalimpulses, release neurotransmitters |
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Major parts: cell _________ ,
d_________ , a_________ |
cell body, dendrites, axon |
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-Cell body: has _________ and other _________ |
Cell body: has nucleus and other organelles |
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-nuclei- _________ ofcell bodies in CNS |
nuclei-clusters of cell bodies in CNS |
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ganglia- _________ ofcell bodies in PNS |
ganglia-clusters of cell bodies in PNS |
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-dendrites: thin branched extensions of _________; _________ input from other ______ (_________ & _________ ) |
dendrites: thin branched extensions of cytoplasm; receive input from other cells (excitatory & inhibitory) |
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-axon: _________ , often _________ extension of _________ |
axon: large, often long extension of cytoplasm |
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-axon hillock –near ______ _________ ; where action potential _________ |
axon hillock –near cell body; where action potential originates |
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-collateral axons –side _________ |
collateral axons –side branches |
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-axon terminal –_________ neurotransmitters |
axon terminal –releases neurotransmitters |
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-Axoplasmic flow –_________ movement of _________ down _________ |
slow movement of material down axon |
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-Axonal transport –rapid_________ transport in_________ directions; involves_________ |
Axonal transport –rapid selective transport in both directions; involves microtubules |
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-sensory (afferent) neuron –conduct _________ from _________ receptor to _________ |
sensory (afferent) neuron –conduct impulses from sensory receptor to CNS |
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-motor (efferent) neuron –conduct _________ out of _________ to _________ organs (e.g. muscles, glands) |
motor (efferent) neuron–conduct impulses out of CNS to effector organs (e.g. muscles, glands) |
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Somatic motor neurons –_________ and _________ control of_________ muscle |
Somatic motor neurons –reflex and voluntary control of skeletal muscle |
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Autonomic motor neurons –innervate _________ effectors(______ ______&______) |
Autonomic motor neurons –innervate involuntary effectors (smooth/cardiac muscle & glands) |
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Interneurons –located in _________ and______ ______ in CNS |
Interneurons – located in CNS and interconnect neurons in CNS |
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Types of Neurons Based on Structure ______ e.g. primarily found in ______ ______ ______ e.g. primarily found in ______ of ______ ______ e.g. most ______ (e.g. ______) |
Types of Neurons Based on Structures pseudounipolar e.g.primarily found in sensory neurons bipolar e.g. primarily found in retina of eye multipolar e.g. most common (e.g. motor neurons) |
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Glial cells: _________ cells ->-nourishment; aid in_________ ; supporting _________ , etc. |
Glial cells: supporting cells ->- nourishment;
aid in function; supporting framework, etc. |
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-Support cells of PNS: Schwann cells –form _________ around _________ Satellite cells – _________ neuron cell bodies within _________ of _________ |
Support cells of PNS: Schwann cells –form sheath around axons Satellite cells –Support neuron cell bodies within ganglia of PNS |
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Support cells of CNS: 4 |
Support cells of CNS:
Oligodendrocytes Microglia Astrocytes Ependymal cells |
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Schwann Cells -form living _________ (______)around _________ & _________ axons of PNS |
Schwann Cells-form living sheaths (neurolemma)around myelinated & unmyelinatedaxons of PNS |
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Myelin sheath –_________ coverof some _________ ---> _________ conduction of _________ ! Schwann cell wraps around______ of single _________ |
Myelin sheath –insulated cover of some neurons ---> faster conduction of impulse! Schwann cell wraps around ~1 mm of single axon |
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Nodes of Ranvier:_________ b/w adjacent_________ cells |
Nodes of Ranvier:gaps b/w adjacentSchwann cells |
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If nerve of PNS injured: -distal part of nervefiber _________ -_________ cell formstube to provide_________ for_________ re_________ Note: Re_________ inCNS very limited due toinhibitory _________ & _________ |
If nerve of PNS injured: -distal part of nervefiber degenerates -Schwann cell formstube to providepathway for axonregeneration Note: Regeneration inCNS very limited due toinhibitory proteins & scar |
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Oligodendrocytes-form _________ sheath in CNS -_________ oligodendrocyte_________ portions ofseveral _________ -white matter in CNS --->parts of CNS with lots ofmyelinated axons |
Oligodendrocytes-form myelin sheath in CNS -single oligodendrocytemyelinates portions ofseveral axons -white matter in CNS --->parts of CNS with lots ofmyelinated axons |
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Multiple sclerosis –myelinsheath _________ --->inhibitsnormal _________of _________ |
Multiple sclerosis –myelinsheath destroyed --->inhibitsnormal conduction of impulse |
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Microglia: mig______; ____cytosedebris, ______, p_______ |
Microglia: migratory;phagocytosedebris, waste,pathogens |
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Ependymal cells:line ________(cavities)of _________ and centralcanal of _________ cord |
Ependymal cells:line ventricles (cavities)of brain and centralcanal of spinal cord |
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Astrocytes: help ______neuron’s external enviro in____; interact metabolically w/_____ 1. K+ uptake from_________ fluid 2. Neuro_________uptake 3. End feet take up_________ from _________ 4. Induce _________ of blood-_______ barrierblood _____barrier:tight junctions b/w capillary endothelial cells restrictpassage of most substances -->highly______ |
Astrocytes: help regulate neuron’s external enviro inCNS; interact metabolically w/ neurons 1. K+ uptake fromextracellular fluid 2. Neurotransmitteruptake 3. End feet take upglucose from capillaries 4. Induce formation of blood-brain barrierblood brain barrier:tight junctions b/w capillary endothelial cells restrictpassage of most substances --> highly controlled |
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Membrane Potentials- all _________ have_________ __________________(RMP) due to _________ of charge across_________(RMPneuron = -70mV) |
Membrane Potentials-all cells have resting membrane potential(RMP) due to separation of charge acrossmembrane (RMPneuron = -70mV) |
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-Excitable tissues = n_________& m_________ cells --->_________ transient, rapid _________ in membrane_________ in response to _________ |
-Excitable tissues = neurons & muscle cells --->produce transient, rapid changes in membrane potential in response to stimulus |
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Depolarization: inside of _________becomes more _________ thanRMP (_________) |
Depolarization: inside of cell becomes more positive than RMP (stimulation) |
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Repolarization –_________ to RMP after _________ |
Repolarization –return to RMP after depolarization |
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Hyperpolarization: _________ becomes more _________ than RMP (_________) |
Hyperpolarization: inside becomes more negative than RMP (inhibition) |
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Ion Channels -membrane_________ changes due to change in _________of membrane to _________ -->ion c_________ |
Ion Channels -membrane potential changes due to change in permeabilityof membrane to ions --> ion channels |
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Leakage channels _____ leakagechannelsalways _________ -->allows _____toleak out |
Leakage channels -K+ leakagechannelsalways open --> allows K+ toleak out |
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Voltage-gated (VG)channels -Na+ ____ channel-K+ VG channel-Ca2+ VG channel Open when potential changes (action potential) IDK |
Voltage-gated (VG)channels -Na+ VG channel -K+ VG channel -Ca2+ VG channel Open when potential changes (action potential) |
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Ligand-gated channels -open when_________ (e.g._________)bind |
Ligand-gated channels -open whenchemicals (e.g.neurotransmitters)bind |
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Action Potential -all-or-none_________ event in _________ or muscle _________in which polarity of membrane potential rapidlyre_________& re_________ |
Action Potential-all-or-none electrical event in axon or muscle fiberin which polarity of membrane potential rapidlyreverses & reestablishes |
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Action Potential due to _________ in membrane _________ to ________ (K+ and Na+) -Na+ VG channels_______ quickly --> Na+_____in with electro chemical _______ -->inside more (+) -K+ VG channels _______ slowly -->then K+ _______ out with electrochemica_______-->inside ______to (-) |
Action Potential due to changes in membrane permeability to ions (K+ and Na+)
-Na+ VG channels open quickly --> Na+ diffuses in with electro chemical gradient --> inside more (+) -K+ VG channels open slowly --> then K+ diffuses out with electrochemical gradient --> inside returns to (-) |
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All-or-None Law If membrane potential (MP)below threshold ... -->VG channels _________open -->_______ AP |
All-or-None Law If membrane potential (MP) below threshold ... -->VG channels don’t open --> no AP |
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All-or-None Law If MP reaches threshold (-55mV)... -->VG channels _________ -->AP _________ |
All-or-None Law If MP reaches threshold (-55 mV)... --> VG channels open --> AP happens |
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All or none --> eitherhappens or doesn’t AP _________has same amplitude& _________ in given tissue |
All or none -->eitherhappens or doesn’t AP always has same amplitude& duration in given tissue |
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Coding for Stimulus -Since amplitude is _________the same...↑ _________ strength can’tproduce_________ AP amplitude e.g. If shock nerve, ↑ voltage doesn’t ↑AP amplitude once threshold reached |
Coding for Stimulus -Since amplitude is alwaysthe same...↑ stimulus strength can’tproduce higher AP amplitude e.g. If shock nerve, ↑ voltage doesn’t ↑AP amplitude once threshold reached |
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Coding for StimulusInstead: ↑ stimulus frequencyresults in ↑ APfrequency _________ modulated (More on this with EPSPs and sensory physiology) |
Coding for StimulusInstead: ↑ stimulus frequencyresults in ↑ APfrequency FREQUENCY modulated (More on this with EPSPs and sensory physiology) |
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Refractory Period -APs _________travel in ______ direction (axon h_______ --> axon t_______ ) |
Refractory Period-APs always travel in one direction(axon hillock --> axon terminal) |
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Why? _________ period! --> once AP already _________ , another stimulus _________ trigger a new AP in _________ spot |
Refractory period! --> once AP already occurring, another stimulus can’t trigger a new AP in same spot |
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Absolute Refractory Period -_______ of response to new ______ during an AP --> Due to _________ of Na+ _________ --> haven'tto return to _________ (resting conformation) -->can’t _________ --> Na+ can’tenter -->2nd AP _________ |
Absolute Refractory Period -lack of response to new stimulus during an AP --> Due to inactivation of Na+ channels --> haven't to return to closed (resting conformation) --> can’t open --> Na+ can’t enter --> 2 nd AP impossible |
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Relative Refractory Period-________immediately following _________ refractoryperiod in which initiation of ___nd AP inhibited -->occurs during the after hy_________ -->K+ still leaving through ___ channels -->_________ would be evenmore (-) than at RMP...so _________ difficultto reach threshold --> _____ AP |
Relative Refractory Period -interval immediately following absolute refractory period in which initiation of 2nd AP inhibited --> occurs during the after hyperpolarization --> K+ still leaving through VG channels -->inside would be even more (-) than at RMP...so more difficult to reach threshold --> no AP |
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What happens if artificiallydepolarize membrane tothreshold in middle of axon? |
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-cytoplasm is poor _________ of charges→ cable properties_________ e.g. if inject (+) charges to causedepolarization just below threshold… …only travels __ - __ mm ... then _____ off |
-cytoplasm is poor conductor of charges→ cable properties low e.g. if inject (+) charges to causedepolarization just below threshold… …only travels 1-2 mm ... then dies off |
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CableProperties & Conduction of AP -Nerveimpulses ______ rely on cable properties -APs must _________ about every 1-2 mm -Eachnew AP has same amplitude & _________ -Conductedwithout _________ …strength doesn’t ↓ with _________ |
CableProperties & Conduction of AP -Nerve impulses DON’T rely on cable properties -APs must REGENERATE about every 1-2 mm -Each new AP has same amplitude & duration -Conducted without decrement… strength doesn’t ↓ with distance |
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Conductionin Myelinated Axon -_________ insulated! -APs only_________ in nodes of_________ -Na+ and K+ VG channels &Na+/K+ pumps highly _________ in nodes |
Conductionin Myelinated Axon -axon insulated! -APs only generated in nodes of Ranvier -Na+ and K+ VG channels & Na+/K+ pumps highly concentrated in nodes |
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Saltatoryconduction: AP‘_________ ’from node to _________ -->_________ conduction rate! |
Saltatoryconduction: AP‘leaps’from node to node -->FASTERconduction rate! |
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Conductionin Unmyelinated Axon -no _________ ! -APs mustbe_________ down length of _________ |
Conduction in Unmyelinated Axon -no insulation! -APs must be regenerated down length of axon |
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Howwill this affectconduction rate? |
SLOWER! |
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If thicker (↑ diameter) --> slightly higher _________ rate! |
If thicker (↑ diameter) --> slightly higher conduction rate! |
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↑ diameter and myelination --> ↑conduction rate -thin, unmyelinated nerves (slow,______ response) --->1 m/sec -thick, myelinated nerves (quick,_________ reflex) --> 100 m/sec |
↑ diameter and myelination --> ↑ conduction rate -thin, unmyelinated nerves (slow, visceral response) --> 1 m/sec -thick, myelinated nerves (quick, stretch reflex) --> 100 m/sec |
