GAP Nervous System Guided Notes PDF

Nervous System The master controller of the entire body. What does this system do? Regulates allfunctions of thebody Recievesall incoming stimulithataffectthebody Cellscommunicateviaelectricalandchemicalsignals saidtobe it...

Nervous System The master controller of the entire body. What does this system do? Regulates allfunctions of thebody Recievesall incoming stimulithataffectthebody Cellscommunicateviaelectricalandchemicalsignals saidtobe it Irked 911am There are 3 overlapping functions action signals p otential of the nervous system. Describe each below: negationBY 55 itriYtaIonm sensory input Motoroutput responsetostimuliactivates.ae toproduce response ogriaggans Organization of the Nervous System Describe the different branches of the nervous system below. (Draw a diagram below that helps show how they are interconnected) iiiiiiiiitn III darrives atm t.IE Os PeripheralNervousSystemPNS pairedspinal cranial nerves branchesoff tofromspinalcord alneticfight flignyPN messages quarries gg ahhfkrestdigest 2 functional divisions pargy.hn Sensory afferent division 89Iy romiiseeiatai.ie p.MisI in Visceral afferentfiberstransmitimpulses u Autopific from visceralorgansto CNS Motorefferent division transmit impulsesfromCNStoeffector s theticN.S Parasympathetic 628ha c nervessystemSheletal consciouscontrol of muscles utgeiei.im ma Regions and Organization e Central Nervous System - Brain and Spinal Cord What are the 4 main adult brain regions 1. 2. 3.in ii iiiiiiiiiiism 4. Cerebellum inback Describe the makeup of the Cerebral Cortex: Outerlayer of brain Made of greymatter executive suite of brain urMY bedrouhY.IS lowersignal Cortex is arrangedintofolds of nerve tissue Site of Conscious mind awarenesssensory surfaceareaand perceptionmotor increases of nerves 2 4 am superficial layerof gray Underneath cortex is whitematter matter Myelinated neurons composed of neuron cell bodiesdendrites Association.no IvesandttYguaterggnderues glial cellsand blood vesselsbut no axons neuroglia Dividedinto 2 hemispheres that are contralateral 40 mass Dendrites  Rightsidecontrolslefthand of brain 1 54 Four general considerations of the cerebral cortex: 1. Contains three types of functional areas: Motor areas:controlvoluntarymovement axon I neuroglia Sensory areas:Consciousawareness of sensation Association areas:integratediverse information 2. Each hemisphere is concerned with contralateral (opposite) side of body 3. Lateralization (specialization) of cortical function can occur in only one hemisphere 4. Conscious behavior involves entire cortex in one way or another leftusrighthanded Corpus Callosum: Describe this structure below- Connects thehemispheres allowsthemto communicate white fibers men tending This Each hemisphere of the cerebral cortex is divided into five lobes. – The lobes are areas of common function Itigheaissue _______________ – these areas contain neurons that carry signals to PNS to control something in the body. __________________ – these areas contain neurons receiving signals from the body. MA has small g roove gyri between __________________ – these areas contain neurons for communication and memory. tion – Nerves in the CNS are divided into tracts. Describe what a tract is-groups of nerveswiresthattravel unit sc – tothesame area transmit in thesamedirection Brain Lobes and their functions 11thYin5951in For each of the following lobes, 1. List the functional areas found there and 2. Describe the area. Frontal Lobe Takes - longest to develop fasterin females for ifi_man Responsible Personality and Intellect Broca's areacontrolsmuscles thatlet you speak onlysound motorcortexstroke paralyzesmust at leta'muscusvoluntary located.imentralgyrus controlled bythoseareas t.fi ittiigmimt Premotor associationAreadeveloplearnedmovementswrite ridebike ofolfactorycortexsenseofsmellsplit wtemporallobe Paralysis occurs body from damage on opp sides of WYETHParietal Lobe - frombodysurfacetissueslocated gyrus SomatosensorycortexSensoryinput if Popstential S contestant d.is5 c winesmen it learn Wernicke'sAreasharedwtemporallobe Ability to understand formspeech Words Temporal Lobe - tohearsounds interpret Auditory CortexAbility Auditory Association Areamemories of all sounds cat vs dogsound ontal ofOlfactorycortex Occipital Lobe - Wavelike's Areaparietal snared Visual CortexAllvisualinputgoesheretointerpret VisualAssociation AreaUnderstanding Memoryof visuals yousee rememberingthings Insula -Deeptotemporal lobe Vestibular CortexBalanceandposition of body Visceral AssociationAreaMonitors allvisceral input stomachache fullbladder Gustatory CortexTaste andmemoryoftastes  Diencephalon The area below the cortex. Describe the functions that occur in each of the areas below. Formed by the: – Thalamus Postofficetobrain Sortsandsendssignals to theright area – Hypothalamus ControltheANS Regulateshunger thirsttemp Controlsmostendocrinefunction Limbicsystememotions Mammillarybodies containsmell reflexes – Epithalamus - Pineal gland (body) Melatonin regulates sleepcycle Brain Stem Part that attaches the brain to the spinal cord. Describe the functions that occur in each of the areas below. Made up of: – Midbrain ra Quadrigemina Reflexes forheaving andvision startle reflex – Pons ftp.ioncentrantpgsthm ofbreathing – Medulla Oblongata Connection to spinalcord T.IEpipi Eii inhalation finitation reene – Reticular formation Graymatter in brainstemregulatesvisceralactivity and consciousness Coma Cerebellum Functions? – Coordinates skeletalmuscle activity –Monitors joint position Describe this structure below: matter Contains gray white White mattercalled the ArborVitae treeof life Damage to thisareacancause ataxia Drunken and uncoordinated movements  Meninges Coverings around the CNS. It is made up of 3 layers, describe each of them below: 1. Dura mater - Mladistof Falxcerebri Duramatergoesdownintostructure 2. Arachnoid mater - tentaclesweblooking MiddlelayerformssubarachnoidspaceanddrainCSFintoveins 3. Pia mater - thinDelecatedirectlyonbrain Describe what meningitis is - int9Eaftfchs.MG chleadsto inflammationofbrain encephalitis Cerebral Spinal Fluid byobservingmicrobes insample meningitisusually diagnosed of CSFfromlumbar – Describe what CSF is and its importance in the brain. Homeostatic Imbalance choroidPlexus Formed by ordraining HydrocephalusobstructionblocksCSFcirculation supportsnourishesbrain in resulting increasedpressure Brainfloats in fluid in are skullbones unfused newborns so increasedpressurecauses malinadhYkeepspressurecanleadtobraindamage die nerves Drained byArachnoidvilli try todrainfluid Ventricles of the Brain The diagram above shows the locations of the ventricles of the brain. Describe where the 4 main ventricles are located and other important associated structures. filledwith CSF lined wependymalcells move CSFwcilia Connected to oneanother central canal of spinal cord Lateral ventricles 3rd ventricle viainterventricular foramenholethatconnects lat3rd Thirdventricle connects with ventrick via cerebral aqueduct  Protection of the Brain: Describe the 4 structures that provide protection to the brain. 1. Meninges _________________ – 2. CerebrospinalFluid– _________________ 3. Cranium _________________ – 4. Blood Brain ________________________________ Barrier selective barrierbetween bloodvessels of brainnerve cells Allowsglucoseaminoacidselectrolytes Barrier is lackingaround part of brainstemhypothalamus holinicotine Blocksmetabolicwasseproteinssometoxins no ang Problems in the Brain Describe each of the conditions below! CVA – Cerebral Vascular Accident (stroke) – TIA –Bloodvesselburstleakesbloodtemporaryepisodes of reversiblecerebral ischemia bloodflowto ANYtissue – Ischemia –Bloodvesselis blockedno 02orblood to otherpartsof brainlossof Concussion Brain - Canlead tobraindamage c ausesbruising moves Coma –Prolongedstateofunconsciousnessreticularformationaffectedcaused byinjury or medicinedrugoverdose Alzheimer’s disease (AD) ofbrainthatresultsindementia Progressive degenerativedisease keyproteins are misfoldedandmalfunction kikmwtkn.lytangles w interfere transfort memoryloss shortattention spandisorientation lossmoodinessconfusion Asbraincellsdiebrainshrinks language Plaquesareasofbadproteins Spinal Cord Describe the overall structure of the spinal cord: mktnatdkistr.mkun.fm network ofveinsinspace between ar GMashitonmother outerareasofcord which Bagaughingfortat ray inoutside middle Protected bybonemeningesandCSF in Dural.gr FdYhhh lnmfixing Themembegeaenda 18 atwork white Spina thick Describe 91Mattanfooterhae 1 the following spinal cord structures and their locations: – conus medullaris -wheresolidcontinuousspinalcordstopsAround cone L – cauda equina - remains of spinal cord of spinalnerves w̅ attaches tosacrum – filum terminale -last partofpiamatterthat Spinal Nerves 31 pairs exit off of the spinal cord through the intervertebral foramen. List the different pairs below: 8 cervical 12 thoracic 5 lumber 5sacral 1 9,99 The spinal nerves are constructed from nerve fibers that extend from the ventral and dorsal aspect of the cord. – Describe how the dorsal root differs from the ventral root of the spinal nerves: Dorsalroot is inthebackhasbulge ganglion Sensorynerves nerve brain Ventralroot is front motorbrain nervesmostcommonlypinchedwhendiskbulgles Cross-Sectional Anatomy of the Spinal Cord Spinal Cord Tracts Name and describe the main tracts found within the spinal cord: Prymidaltract motorventral Fasciculus sensorydorsal iritis  PNS(Peripheral Nervous System) Made up of all the nerves that extend off the CNS. – These nerves are made from nerve fibers (axons). – These nerves can be sensory, motor, or both. Describe how cranial nerves differ from peripheral nerves: Cranial extendoffbrain toinnervatetheheadneck Peripheral maindivisionsofspinalnerves bothsensorymotorfibers i nnervatebody Reflexes quickersignal Reflexes Describe what a reflex is: fromsensorynervetocarsandbackto nerve motor YETrisep the L Reflex Arc - label the parts to the reflex arc below: isensorynerve 2 interneron Receptor Labeling 3motornerve Sharon gland 4effector muscleor internueron htion effector Autonomic Nervous System What is the autonomic nervous system?Involuntary What are some body activities that it controls? heartratedigestionrespirationratehormones Bloodflow Centered in the _____________________ hypothalamus of the brain. Two divisions (antagonists to each other):ParasympatheticRest digest Sympathetic – Thoracolumbar (T1 to L3) fightflight sympathetic – Describe this branch and some of the changes that occur in the body when in this system: Prepareus for action Uses Norepinephrine asmain nuevo transmitter Adrenaline Enhanced by Epinephrine Changes in body Ease retiatory algetititivity bloodflow Parasympathetic – Cranial – Sacral – Describe this branch of the ANS and some of the changes that occur in the body when in this system: Decrease in bodyactivity Increasethevisceralactivity of digestion metabolism transmitter is ACH Main nuero Changes in body Ease reshiatory digestive citing a bloodflow  Histology of Nerve Tissue Highly cellular; little extracellular space Tightly packed The two principal cell types of the nervous system are: Neurons (nerve cells) – Fastcellsthattransmitelectricalsignals ftp.Ympise1cinthpotentials Supporting cells (neuroglia)– Cellsthatsurroundwrapneurons Connect protectandsupportneurons CI of nervoussystem 1. Astrocytes - Describe: highlybranchedclingto neuronssynapticendingscovercapillaries bloodyIn What are the functions of this cell? 1 Support brace neurons regulatewaste nutrients 2Anchorneurons totheirnutrientsupplies help ih nTa iihitTTt tr in n n 2. Microglia – Describe: oval Piscisses small thattouchmonitorneurons What is the function injured of this cell? towards migrate neurons Phagocytic 14191 piddlebutdoNot forbrainspinalcord causeinflammation better 3. Ependymal cells – Describe: SquamouscolumnarCiliated What is the function of this cell? S an if ite brainspinalcolumn 4. Oligodendrocytes– Describe: BranchedLargewrapCNSnervefibers What is the function of this cell? createstheinsulatingmyelinsheath in CNS Cellswrapto createwhitematter fastsignal 5. Schwann cells (neurolemmocytes) – Describe: surroundPNSnervefibers small What is the function of this cell? signal kinasedrama eriinaiiimei.ir 6. Satellite cells – Describe: What is the function of this cell? Cushions Protects nerves in PNS coverscellbody functionsimilarto astrocytesofCNS  Neurons (Nerve Cells) Structural units of the nervous system Describe characteristics of a neuron: dendrite axon a'jiIt Projections 19 1 1ae amkh9knananenihnn Their plasma membrane function in: Electrical signaling Cell-to-cell signaling during development Neuron Processes - Armlike processes extend from body __________________ - Bundles of neuron processes in CNS truffles samethingjustdiffnamesfordifflocations __________________ - Bundles of neuron processes in PNS Two types of processes: Dendrites Short Axon long Draw a typical nerve cell (neuron) below and label its major structures! In addition, there is a neuron model in the lab that you will be required to identify these structures on! Dendritesreceptiveareas nucleus Umminals Cellbody Erika axon of Ythier Shyam 4 Major parts (Describe each part below!): Dendrites receptiveareas Branchedprocesses cellbody as gradedpotential Conveyincomingmessage toward shortdistancesignal Cell Body Axon attach toothercellssendneurotransmitters Axon terminals 5 Minor parts (Describe each part below!): Axon hillock funnel shape Nucleus controlcenter Nissl bodies membrane bynucleusroughER that makes neurotransmitter Schwann cells form myelinesheeth inPNS Node of Ranvier gapsbetweenShwanncells  Structural Classification of Neurons Grouped by number of processes Three types: Describe each below and where they are typically found. You might want to also draw an example of each! – Multipolar neurons– 3 or more processes 1axonotherdendrites Mostcommonmainneuron inCNS – Bipolar neurons– 2 processes I axonand I dendrite Retinaandolfactorymucosa Rare – Unipolar neurons– 1 short process if itp.ie i iieta renter Neuron Classification Functional: Sensory (afferent) — transmit impulses toward the CNS Describe: Maybemyelinatedorunmyelinated AhhSee Yarizeddeicariticreceptors foreachstimulireceived Examples: – _____________________ Mechanoreceptors = touch, vibrations, pressure, stretch – Thermoreceptors _____________________ = temperature (hot vs. cold) – _____________________ Chemoreceptors = monitors chemical levels (taste buds, Ca2+ receptors, smell receptors) – _____________________ Photoreceptors = rods and cones in eyes to detect color or black/white light – _____________________ Nociceptors = pain receptors Motor (efferent) — carry impulses away from the CNS Describe: muscleor gland 51 effete 11,9 0 giant myelinated Very spird this brain Interneurons (association neurons) — shuttle signals through CNS pathways Describe each and how they differ: neurons bettertetany andfromsidesofbrainto each other motornerves Actasrelaypointsforsensorynervesto Neurophysiology Neurons are highly irritable (means? ____________________) canbestimulatedeasily Action potentials, or nerve impulses, are: Electrical impulses carried along the length of axons Always the same regardless of stimulus samesize AP The action potential is the underlying functional feature of the nervous system  Role of Membrane Ion Channels Large proteins serve as selective membrane ion channels Two main types of ion channels – Leakage (nongated) channels -Alwaysopenflowthrough – Gated channels - Partofproteinhastochangeshape toopenclose channel There are three types of gated channels: Chemical (ligand-gated) channels - Openwithbinding ofspecific neurotransmitter Voltage channels - Openclose in response to changes inmembranepotential Mechanical channels -Physicaltouchlight Openclose in to physicaldeformationof receptors response as in sensoryreceptors non SlighMegative The Resting Membrane Potential Potential difference across membrane of resting cell Eitan ions diffusequickly t9 – Define what the term polarized means - has a charge conchetgradients Generated by: electgradientstoward Opposite charge Differences in ionic makeup of ICFandECF weates elect Differentialpermeabilityof plasma membrane ion flow acros current voltagechanges membrane  Membrane Potential Changes Used as Communication Signals What causes changes in membrane potential? of ions across membrane change Concentration Membranepermeability toionschange Changes produce two types of signals: – Graded potentials - overshortdistances Ihit boogerating – Action potentials - of Typdistancesignals axons Changes in membrane potential is used as signals to receive, integrate, and send information Changes in Membrane Potential 1. Describe what Depolarization is: A reversal of membrane potential Causescellmembraneto becomelessnegative use Nat Natgoesin ansdsypotarhh.ggdunsate neurotransmitteropens mother ligandgate to 2. Describe what Hyperpolarization is: An increaseaway fromzero Inside is MOREnegativethanresting membrane potential Reducesprobability of producing a nerve impulse thtout or Ct in  Graded Potentials totteriahardtittial Short-lived, localized changes in membrane potential Magnitude varies with stimulus strength light Stronger stimulus → more voltage changes; farther current flows What are the two types of graded potentials? Depolarization or Hyperpolarization Where do graded potentials occur in the neuron? Dendrites What triggers a graded potential? Stimulusthat opens gatedion channels Why are graded potentials short lived? Currentflowsbutdissipates quicklybecauseonly1gate open Shortdistance Gentian traether 7 The Action Potential When a nerve is stimulated, it will undergo a process of being excited and creating an impulse called an Action Potential – Where do action potentials occur? Cell body axons – What are they used for in neurons? Sendingsignals – Why don’t action potentials decay like graded potentials do? uses voltage gate GradedPotentialopensitoncereachesthreshold alongaxontokeepNatcomingin Opensgates doesn't stop Changes in Membrane Potential Changes are caused by three events Depolarization –inside less negative Natin Repolarization –Returns tovesting It out Hyperpolarization –insidemorenegative Notall kt goesoutright away short distance Fiona Yagesties or iMandy L Dendrites Axon 1 Resting State 2 Depolarization state 3Repolarization phase 4 Hyperpolarization Depolarization Starts with stimulation. What are some ways the neuron can be stimulated? touchpressure hotcold neurotransmitter What happens to the neuron once it is stimulated? Natgoes in less negative Bnma Not every stimulation will result in depolarization. Why? if notenough gradedpotential threshold mygift As the electric charge elevates, it will cross a level called threshold. Define threshold - Minimumlevel of stimulation to create an impulse Can happen at once or in successive attempts. Excitation Potential – EPSP and IPSP InhibitoryPostsynaptic Potential Postsynaptic What is Summation? Addition of signalsfromdifferentplaces All or Nothing Action. What does this mean? if makeit toAPnothingcanstopif doesn'tmake itnothingwillhappen As the membrane depolarizes, the action potential will travel down the nerve to the axon terminals. The action potential ALWAYS travels in what direction in a neuron? Cell body axonterminals What happens in the neuron when the action potential reaches the axon terminals? Release of neurotransmitter chemical to stimulate the next nerve or effector in muscle As this process (Depolarization) peaks, it will lead into the recovery phase. Repolarization After the membrane depolarizes, the membrane potential has to be restored to its resting state. Why must this occur? Nervecellwouldbelocked wouldn'twork Repolarization begins as depolarization peaks. Describes what happens in the neuron to restore the membrane potential: Natgates willclose stopcoming in kt gatesopen leavescell Natktpumpstartsto getridofNatbring in kt restored Membranepotential is  Absolutelycannot sendmore Refractory Period = This is the amount of time it takes to repolarize. Absolute refractory period – neuron can’t perform another APduringtime action potential at this time! – When does this occur during an action potential? Timefromopening of Natchannelsuntilresettingof Channels – Why is this period of time important? Ensue eachAPisallornoneevent Enforcesonewaytransmissionofnerveimpulses Relative refractory period – When does this occur during an action potential? RightafterAbsolute atopen 88 ipmfan.laohhange – 89 Threshold for AP generation is elevated – Exceptionally strong stimulus may generate an AP during this period. Hyperpolarization Describe what this is: tonormal aonitiihiiPanaiiI Whatin Entes name causes this to occur during an action potential? kt Propogation of an Action Potential Once initiated an Action Potential is self-propagating – In non-myelinated axons each successive segment of membrane depolarizes, then repolarizes – Propagation in myelinated axons differs Conduction Velocity Conduction velocities of neurons vary widely Rate of AP propagation depends on: – Axon diameter - Somearewidernarrow Wider faster – Degree of myelination - Continuousconduction in unmyelinatedaxons is slowerthan Saltatory conductionin myelinated axons Effects of Myelination: Why do myelin sheaths speed up an action potential? insulatepreventleakage ofcharge Review - What cells form the myelin sheath in the CNS?_________________ Shwann Cells in the PNS? _________________ Saltatory conduction (possible only in myelinated axons) is about 30 times faster. Describe this process: VoltagegatedNat channels are locatedat myelinsheathgaps AP generaged onlyatgaps to jumprapidlyfromgaptogap 8999 Saltatory Conduction appears thenideateTheds a Natin gattage 11 1 Importance of Myelin Sheaths: Multiple Sclerosis Describe what Multiple Sclerosis is: Autoimmune diseaseaffecting youngadults Painsafu I reliapse remission means hstimiat.at Symptoms? Y'eied.iTphdEndukYn toEmailedindroses visualspeechdisturbancesweaknesslossofmuscle controlurinary incontinence What are some treatments? Drugsthatmodify immunesystem Bonemarrow transplant Prevention? HighbloodlevelsofvitaminD reduceriskofdevelopment Nerve Fiber Classification Nerve fibers classified according to: DiameterDegreeof myelinationspeedof signal Describe the following types of fibers: – Group A fibers - largeverymyelinatedskeletalmusclejoints 1Penitual – faraway Group B fibers - Intermediate lightlymyelinated Intake body – ofGroup C fibers - SmalldiameterunmyelinatedANSfibers Ithnomic doesn'tneed tobefast Synapses What is a synapse? connection by axonterminals ofonenerve thedendritescellbodyoraxonofanothernerve betweennervecells formed Nervous system works because information flows from neuron to neuron. Helps to relay signals. Describe the following types of synapses: Chemical synapses- Specialized for releasereception ofchemical neurotransmitters initial iii exocytosis mifiapeani Talon.fi agrarian neurotransmitter aahlea imtg.in namethen Neurotransmitter neuron'smembrane receptor anegiononcePostsynaptic Electrical synapses- Electric AP Chem Electric YeahIdgafcoupled joined if gaspjunctions thatconnectcytoplasm of adjacent newons fakm.be orbidirectional Nerveimpulseremainselectrical gniqggtiyonal Synapse Classification Describe the different types of synapses (how nerve cells connect) below: Axodendritic -axonterminal dendrites mostommon Axosomatic - axonterminal cellbody Less common types: Axoaxonic -axonterminal axonhillock Dendrodendritic -dendrite dendrite brain Somatodendritic -dendrite Cellbody Important Neurotransmitters Acetylcholine–Excites NMJused in somatic NS PNS excites toparasympatheticNS Norepinephrine –Used in CNSPNSexcitessympatheticNS Suppressesparasympathetic Dopamine –Predominantly in CNSexcitatory to hypothalamus feelgood neurotransmitter Addictive drugsexcitedopamine receptors Serotonin–CNS Antagonist to dopaminedepressant inhibitory Presynaptic  1 postsynaptic Postsynaptic Potentials (discussed briefly above) Neurotransmitter receptors cause graded potentials that vary in strength with: –Amountof neurotransmitter released –Timeneurotransmitterstaysinarea REVIEW: List some differences between graded potentials and action potentials below: Graded potential Action potential Types of postsynaptic potentials. What is a postsynaptic potential? – EPSP—excitatory postsynaptic potentials Describe what this is: neuroticismT.mbitandedlshldofhenmi.lt 999,5atttions Natinfluxgreaterthan ktefflux lessneg EPSP EPSPshelptriggerAP ifEPSPis of threshold strength can spread to axonhillocktriggeropening of voltagegatedchannels causeAPto be generated – IPSP—inhibitory postsynaptic potentials Describe what this is: hllttfptos.peduepostsynaptic neuron'sability toproduce an AP Makes membranemore permeable to 11or Ci Neurotransmitterhyperpolarizescell becomesmorenegative innersurface of membrane APlesslikelyto be generated Synaptic Integration: Summation A single EPSP cannot induce an AP Describe what summation is - AddupFPSP or IPSP tobeabletogettothreshold Most neurons receive both excitatory and inhibitory inputs from thousands of other neurons signal another E wasweakenedby inhibitory Processing Processing is the way the nerves recognize information and the path that it takes. Two types: 1. Serial processing - predictablepathwaythatelicitsthesame responseeachtime As'Ñ ynewon interneuron motoneuron 2. Parallel processing - a Higherlevelawarenessthatwill stimulate a response logicalreasoning orhabit Learnedbehavior meme used byrepetition orYYp.it ItII crasn