BSC 2085 Exam 4 PDF

BSC 2085 Exam 4 LESSON 16 Cerebrum developsfromtelencephalon largestpartofbrain seat of sensoryperception memory thought judgement voluntarymotoractions 2 cerebralhemispheresdivided bylongitudinalcerebralfissure connected...

BSC 2085 Exam 4 LESSON 16 Cerebrum developsfromtelencephalon largestpartofbrain seat of sensoryperception memory thought judgement voluntarymotoractions 2 cerebralhemispheresdivided bylongitudinalcerebralfissure connected corpuscallosum by Frontal lobe rostral to centralsulcus voluntarymotorfunctions motivation foresightplanning memory mood emotion social judgement aggression prefrontal cortex integrates info fromsensoryassociation areas allows us to performabstractintellectualactivities damagehereaffectstemporal relationship betweenevents predictingconsequences Parietal lobe between central sulcus parietooccipitalsulcus integratesgeneralsenses taste somevisualinformation Occipital lobe caudal to parietooccipital sulcus primary visual center of brain Temporal lobe lateral horizontal below lateralsulcus functions in hearing smell learning memory some vision emotion Insula deeptolateral sulcus understandingspokenkinguage taste integratinginfofromvisceralrecept mostofvolumeof cerebrum is composed of cerebral white matter Tracts bundles of nerve fibers in CNS projection tracts extendverticallybetweencerebrum lowerbrain and spinalcordcenters commisuraltracts crossfromone hemispheretoanother allowscommunication mostpassthroughcorpus callosum cutting it totreatepilepticseizures can produce disconnectionsyndrome hemispheres unaware ofoneanother holditem in one hand can'tverballystatewhat it is Association tracts connectdifferentregionswithin the same cerebralhemisphere longassociationfibersconnectdifferentlobes shortassociation fibers connect gyriwithin a lobe cerebral cortex 401 of brain mass 14 to 16billion neurons 901 of cerebral cortex is neocortex 6layeredtissuethathasrecentevolutionaryorig  limbic system importantcenterofemotion learning functional grouping Tethystateage retrieval Ethan m stereotactic astonaristentions relateFersion Primary somatosensory cortex postcentral gyrus site wheresensory input is first received one becomes conscious of the stimuli associationareas near primarysensoryareas process interpret thatsensoryinfo tonfiehenY.tnfthid exhibitssomatopy pointtopoint correspondencebetween an area of thebody an area oftheCNS SLMrimary visualcortex posteriorregionofoccipitallobe receivessignalsfromeyes Hearing primary auditory cortex superiorregion oftemporal lobe receives auditorysignals auditory association area inferiorto primaryauditorycortex recognize spokenwords music voices Taste Smell primary gustatory cortex inferior end of postcentralgyrus primary olfactory cortex medial cortex of temporal lobe sensoryhomunculus diagramp the primarysomatosensory cortex in parietal lobe fats Temingutisaptly contralateralsideof body motorcontrol Voluntarymotorcommands are transmitted to neurons of the precentral gyrus primarymotorarea sendssignals to brainstem alsoexhibits somatopy diagrammed spinalcordleading ultimately to musclecontractions as a motor homunculus formulates phrases transmits Language planofspeech toBrocaarea Posteriorspeech area Wernicke area posteriortolateralsulcus usuallyin lefthemisphere recognition ofspoken written language Motorlanguagearea Broca area inferiorprefrontalcortexusuallyin lefthemisphere generates motorprogram formuscles of larynx tongue cheeks lips for speaking transmitsprogramto primarymotorcortex Aphasia anylanguagedeficitfromlesions in Wernicke Broca's area  Cerebral lateralization difference in structure function between the 2 cerebral hemispheres Left hemisphere usually the categorical hemisphere Engage spot Isequentiansbarggutical breaksinfo down analyzesit Righthemisphere usually the representativehemisphere imkgipgt.ge amrygicf er a atattships myelegrafedway compasses fakessounds in prsetaaigaktag.tttses Electroencephalogram EEG recording of brainwaves helpsw diagnoses 4typesofbrainwaves acatestranslates Alphawaves 8 to 13HZ awake resting w eyesclosed mindwandering α suppressed when eyesopen or performingmental task absentduring deepsleep Betawaves 14to30Hz accentuatedduringmental activity sensorystimulation β appearwhenawake concentrating on something performing task a Theta waves 4 to 7 Hz found normally in children intensely frustrated drowsy or sleepingadults mayindicate a braindisorder or braintumor Delta waves lessthan3.5HE Lightamplitude J deepsleep braindamageIBEÉn gE'caused byinflammation cranial nerve classification sensorynerves CN 1 2 8 carrysignalsonlyfromoutlyingsense organs to the brain motor nerves CN 3,4 6 11 12 stimulate muscle but also contain fibers of  P I Mixed nerves CN 5,7 9 10 sensoryfunctionsmay bequite unrelated to their motorfunction facialnerve 7 has sensoryrole in taste motorrole in facialexpression cranial nerves olfactory nerves I sensoryfunction smell optic nerve 11 sensory function vision oculomotornerve 111 motor function eyemovement motorfunction eyemovement trochlearnerve IV trigeminal nerve v sensory face mouth motor mouth abducens nerves VI motorfunction eyemovement facial nerves VII sensory taste motorfunctions facial expressions vestibulocochlear nerve Vill sensoryfunction hearing balance glossopharyngeal nerve IX sensory taste motorfunc head neck vagus nerve x sensory viscera and motor digestiverespiratory accessory nerve X1 motorfunction neck upper back hypoglossal nerve XII motorfunction tonguemovement LESSON 17 Principal functions of spinal cord conduction axonsconductsensory motor info updown spinalcord neuralintegration spinalneuronsreceiveinputfrom multiplesources integra it and executeappropriate output locomotion spinal cord contains gpgts.ie afntfaEnan8fe EE pgiieusegences a reflexes involuntary responses to stimulithat are vital to posture coordination protection spinal cord cylinderof nervoustissuethatarisesfromthebrainstem at theforamen spite.mgmeth 8YitbfYnSitaloY n liehj each pair ofspinalnerves surface anatomy longitudinalgrooves anteriormedianfissure posterior median sulcus 2 thickest areas cerular'entigement go.EEsEraIeiesrreetic perishmtsnerveof gives region lowerlimbs  medullary cone conus medullaris inferiorpoint ofcord cauda equina bundleof nerverootsthat occupythe vertebral canal from L2 to 55 resembleshorse tail meninges 3fibrousmembranes thatenclosethe brain spinalcord bloodvessels in epidural subarachnoidspace separate soft tissue of CNSfrombones of cranium vertebral canal Dura mater duralsheatharoundspinal cord tough thick membrane composed of dense irregular connective tissue epiduralspace spacebetween dura vertebral bones contains bloodvesselsadiposetissue looseconnectivetissue epiduralblockintroducedhere Arachnoid mater consists of arachnoidmembraneadhering todura separatedfrom pia fibers spanning the subarachnoidspace that is filled w CSF by spestTestifiesintroducedhere inferiortomedullarycone the subarachnoidspace is called lumbarcistern Pia mater delicatetransparent membrane that tafttam.fi ifd follows contours ofspinalcord continues inferiorlyas a fibrous terminal filum whichthenfuses w dura to form coccygealligament denticulateligaments are extensions topresenting hi Element of pia that pass through arachnoid to dura anchoring cord to prevent lateral movement Gray matter nomyelinneuroncellbodiesdendritescentralcoreshapedlikebutterfly 2 posterior dorsal horns receivesensory nervefibers contains sensory somatic visceralnuclei synapse w interneurons in horn 2 anterior ventral horns cell bodies of somaticmotorneurons nuclei connect to peripheral effectors Additional lateral horns only in segments To L associated w sympatheticnervous system has visceral motor nuclei Left rightsides connected by gray commissures central canal at center allows CSF to passthrough interior white matter pearlywhitecolor myelinated white matter survan gray matter 3 largebundles of axonsfuniculus posterior white column proprioception fine touch ventral pressure vibrations anterior  p somatic motor lateral white column funiculus proprioception somatic motor each funiculus subdivided into fasiculi or tracts spinal tracts Ascending tracts carrysensory info up to brain Descending tracts carry motor info down from brain Decussation crossing of midline so that brain senses and controls contralateral side of body Contralateral when origin destination of a tract are on oppositesides of body Ipsilateral whenorigin destination of tract are on same side of body no decussation Poliomyelitis destructionof motorneurons muscleatrophy causedby poliovirus whichspreadsthroughfecalcontamination of water destroysmotorneurons in brainstem anterior horn symptoms musclepainweakness loss of reflexes followed by paralysis muscularatrophy respiratory arrest nospecific cure vaccine to preventpolio Amyotrophic lateral sclerosis ALS or LouGehrigdisease 101 causedby inheritablegeneticmutation rest of unknown cause causes destruction of motorneurons muscular atrophy causes sclerosis scarring of lateral regions of spinal cord earlysigns muscular weakness difficulty speaking swallowing using hands sensory intellectualfunctions remain intact treatment can slow progression but not cure Nerves cord like organ composed of numerous axons bound togetherby connective issue EthesneedsEditedbyElenacompression smaller branches called peripheral nerves wrappings associated structures of nerves Endoneurium looseconnective tissue external to neurilemma surrounds each individual axon in the nerve Perineurium layers of overlapping squamous cells that wrap fasicles bundles of nerve fibers Epineurium collagen that wraps entire nerve  classification of nerves sensory composedonlyof afferentfibers carrysignals from sensory receptors to CNS rare for smell vision motor composed only of efferentfibers carrysignals from CNS to muscles glands mixed bothefferent afferentfibers mostcommontype Ganglion clusterof nerve cell bodiesoutsidethe CNS enveloped in epineurium among the cell bodies are fascicles leading in out of ganglion posteriorroot ganglionassociated w spinal nerves that bring sensory info to spinal cord Spinal nerves 2thoracic sacral1 coccygeal 8cervical g 5lumbar Eachspinal nerve is formed from two roots proximalbranches Posteriordorsal root sensoryinput to spinalcord posterior root ganglion contains neurosomas of sensoryneurons 6 8 rootlets enter posteriorhorn Anterior ventral root motoroutputoutofspinalcord 6 8 rootletsleavecord converge to formanotheranteriorroot Beyond the vertebrae thespinal nervedivides into distal branches Anterior ramus In thoracicregioneachgives rise to an intercostal nerve Inotherregionsanteriorramiformthe nerveplexuses Posterior ramus innervates themuscles joints in that region of skin of the back thespine Dermatome specific area of skin that conveyssensoryinput to a spinal nerve Dermatomemap diagram of cutaneousregions innervated by eachspinal nerve Shingles herpes zoster localized disease caused the virus travelingdown thesensorynerves by by fast axonal transport when immunesystem compromised pain itching common after 50 chickenpox varicella common disease of childhoodcaused early varicella zoster virus VZU by rami branch anastomoserepeatedly Nerve Plexuses anterior to form 5 nerve plexuses cervical plexus in the neck C to Cs supplies neck phrenic nerves to the diaphragm phrenic nerve Cs Cs controlsdiaphragm damageto it can cause breathing to stop Brachial plexus near theshoulder Cs to a supplies upperlimb some of shoulder and neck musculocutaneous nerve flex arm receive sensoryinfo on lateral surface of forearm radial nerve extensormuscles of arm forearm receives sensoryinfo fromposterolateral surface median nerve flexforearm receives sensoryinfo from anterolateral hand ulnar nerve flex hand receives sensory info from medial surface of hand nerve deltoidmusclefor abduction of arm axillary Lumbar plexus in lower back L to Lu suppliesabdominal wall anteriorthigh and genitalia femoral nerve servesmedial anteriorcompartmentof Sacral plexus in pelvis Lu Ls 5 54 supplies remainder leg of lower trunk lower limb including sciatic nerve Thesenerves have both somatosensory fibularnerve tibial nerve motorfunctions Radial nerve crutch paralysis wristdrop Sciatic nerve injury sciatica injury LESSON 8 Reflexes includeglandularsecretion contraction requirestimulation of all 3 types of muscles are quick somaticreflexes involvingsomatic nervous are involuntary systeminnervating skeletal muscle are stereotyped visceralreflexes involvingorgans such as heart intestines reflexesopposeoriginalstimulus negative feedback somaticreflex involves reflex are somatic receptors in skin muscles or tendons afferent nerve fiberscarry info from receptors to posterior horn of spinalcord or to the brainstem integrating center pointof synapticcontactbetweenneurons in gray matter of cord or brainstem efferent nervefibers carry motorimpulses to muscles effectors muscles that carry out the response classifications of Reflexes Bydevelopment Bytypeofmotorresponse Bycomplexityof neuralcircuit By site ofinformationprocessing Development of Reflexes Innate reflexes ex chewingsucking formedbeforebirth basicneural reflexes Acquired reflexes ex ridingbike learned motorpatterns rapidautomatic motor response Somatic reflexes involuntary control of nervous system 1 superficialreflexesofskin mucous membranes corneal gagreflex visceral reflexes autonomic controlsystems otherthanmuscularsystem smooth cardiacmusclesglands adipose tissue complexity of neural circuit monosynaptic reflex sensory neuron synapsesdirectly onto motor neuron one synapseinvolved  Polysynaptic reflex at least one interneuron between sensory neuron motor neuron more than one synapse Sites of info 1 processing spinal reflexes processing occur in spinal cord range in increasingorder of complexity intersegmental reflexarcs spinalsegments interact produce variable motorresponse The stretch reflex monosynaptic reflex arcs onesynapsebetween afferent efferent neurons litte synapticdelay prompt response patellar knee jerk reflex Reciprocal inhibition reflex phenomenon that prevents muscle from workingagainst each other by inhibiting antagonist when agonist is excited Stretch myotatic reflex when a muscle is stretched it fightsback contracts maintainsequilibrium posture stabilizesjoints bybalancingtension in extensors flexors smoothing muscleactions musclespindle manysomaticreflexes involvethese stretch receptors embedded in skeletal muscles serve as proprioceptors specialized sense organs to monitor position movement of bodyparts inform brain of musclelength bodymovement enablebrain tosendmotorcommands backto muscles structureof musclespindle milksgrenentils Intrafusal fibers modifiedmusclefiberswithinthespindle father Ekk fibersthat generateforcefor movement are extrafusal fibers gamma motor neuron innervatesends of an intrafusal fiber keeps it taut anonsCNS to adjustsensitivity of musclespindle ex ofspindlefunction postural reflex PostsynapticReflexes postsynaptic reflex arc pathwayon whichsignals travel over manysynapses on their way to the muscle interneurons controlmore than one musclegroup produceeitherEPSPs or IPSPs at UNS motornuclei 5 general characteristics 1 involvepools of interneurons 2 involvereciprocalinhibition 3 have reverberatingcircuits prolongsreflexivemotorresponse after initialstimulation is gone 4 are intersegmental in distribution more than Ispiral 5 severalreflexes cooperate produce coordinated seg response Flexor withdrawal reflex ipsilateralreflexarc stimulus responseon samsee Quickcontraction of flexormuscles resulting in withdrawal at a limb from an injurious stimulus triggers contraction of the flexors relaxation of the extensors in thatlimb reciprocal inhibition required forflexorreflex to work TendonReflex response to excessivetension on thetendon fromcontractingstrongly tension inhibitory byinhibiting muscle effect tendonorgans proprioceptors in a tendon near its junction w muscle a crossed extension reflex contralateral reflexarc input outputonoppositesides contraction of extensormuscles in limboppositeof the one that is withdrawn stepon sharptack w left foot lift it plantright shiftweight intersegmental reflex input outputoccur at diff segsofspinal c Reinforcement of spinal reflexes highercenters reinforcespinal reflexes bystimulating excitatory neurons in brain stem or spinal cord enhancesreflexes creatingEPSPs at reflexmotorneurons facilitates postsynaptic neurons ex Jendrassik maneuver Inhibition of spinal reflexes highercentersinhibitspinal reflexesby gInEietet suppressing pestiangtic sina.EE  if displayed in adults may indicate as damage Babinski reflexes positive displayed by infants fanningof toes when medial side of sole is stimulated negativeseen in normal adults when stimulated curling plantarreflex occurs neural pools circuits Neural pools functional groupings of neurons each pool has thousands of interneurons concerned w particular body function rhythm of breathing walking Types of neural circuits Divergingcircuit one nerve fiber branches synapses w several postsynaptic cells visualinfogoes tovisualcortex balance area Converging circuit inputfrommany differentnervefibers can be funneled to one neuron or neuralpool subconscious consciouscontrol of breathing Reverberatingcircuit positivefeedback neuronsstimulate eachother in linearsequencebut one or more of the later cells restimulates the first cell to restart process crossextensionreflex Parallel after discharge circuit inputneurondiverges tostimulate several chains of neurons afterdischarge continuedfiring after thestimulus stops stare at light still see wheneyes closed serial processing neurons neural poolsrelay info alongpathway in relatively simple Imearfashion can process one flow of info at a time only can't readbook watch TV at same time Parallel processing info is transmitted alongdivergingcircuitsthrough different pathways that act on it simultaneously for diff purposes drivingrequires processing manythings at same time Spinal cord trauma completetransaction completeseverance of cord immediateloss of motorcontrol below level of injury above Cu threat of respiratory failure  3 forms of paralysis Paraplegia paralysisof bothlower limbs Quadriplegia all 4 limbs Hemiplegia paralysis on one side of body paresis partial paralysis weakness of limbs LESSON 19 Divisions of efferent division somatic nervoussystem operates underconsciouscontrol controlsskeletalmuscles rarelyaffectslongtermsurvival Autonomicnervoussystem visceralmotorsystem operates w conscious instructions controlsvisceraleffectors cardiac smoothmuscles glandsadipocytes coordinatesorgansystemfunctions properties of ANS targetsvisceraof thoracic abdominal cavities some structures of bodywall carries out actions involuntarily visceral reflexes controlledbyANS unconsciousautomatic stereotyped responses to stimulation effectors by involvingvisceral receptors Y.SIhfthef endings thatdetectinternalstimuli 2 afferent neurons lead toCNS 3 integratingcenter interneurons in CNS 4 efferent neurons carrymotorsignals awayfrom CNS 5 effectors carryout end response Divisions of ANS 1Sympathetic preparesbody for physicalactivity fightorflight increasesheart rate BP airflow bloodglucose 2 Parasympathetic calms manybodyfunctionsreducingenergy expenditure resting digestingstate  g Autonomictone normal background rate of activitythat represents the balance of the 2 systems parasympathetictone restingheart rate sympathetictone maintainsbloodpressure bloodvesselspartiallyconstricted Autonomic OutputPathways controlnuclei in hypothalamus otherbrainstem regions ANSmotorpathway vs somaticmotor pathway somaticpathway motor neuronfrombrainstem or spinal cord issues a myelinated axon thatreaches all the wayto skeletal muscles autonomicpathway asignal must travel across 2 neurons togetto the target organ and cross a synapse where these neurons meet in an autonomic ganglion fiberextends to autonomicganglion priegannginie Achreleasedby first postganglionicfiberextends totarget cells either Ach or NE released sympathetic Division Anatomyof sympathetic division its pathways arise from thoracolumbar division relatively short pre ganglionic long postganglionicfibers general pathway cellbodies inlateralgrayhorns cellbodies of pre ganglionicneurons fibers exitspinal cord byway ofspinalnervesT to 12 leadto sympathetic chain of ganglia paravertebral ganglia seriesoflongitudinalgangliaadjacent to bothsides of cervical coccygeallevels sympatheticnervefibersdistributed to everylevel ofbody 7 responses to increasedsympathetic activity heightened mentalalertness increased metabolicrate reduceddigestive functions urinary reservesactivated energy increasedrespiratory rate respiratorypassageways dilate increased heart rate bloodpressure sweat activated  g ganglionicneurons in sympatheticdivisionlocated in 3 areas 1 sympathetic changeganglia 2 collateral ganglia 3 adrenal medulla sympathetic chain ganglia on both sides of vertebral column T.EE dneiatet.Tmsinteaitg Collateral ganglia anterior to vertebralbodies contain ganglionicneurons thatinnervatetissues and organs in abdominopelviccavity Adrenal medulla suprarenalmedullae veryshort axons ganglionicneurons are endocrine cells innervated axons from CNS that travelthroughsympathetic by chain collateral ganglia when stimulated releaseneurotransmitters intobloodstream norepinephrine epinephrine Adrenal glands paired glands locatedon superiorpoles of kidneys each is 2 glands w diff functions Adrenal cortex outerlayer secretessteroidhormones Adrenal medulla inner core essentially a sympatheticganglion hasmodified postganglionic neurons w no dendrites or axons secretes 85 15 epinephrine norepinephrine Sympathetic Division Neurotransmitters Stimulation of sympathetic preganglionicneurons releases Ach at synapses w ganglionicneurons alwaysexcitatory on ganglionicneurons stimulation of sympathetic Ganglionic neurons ganglionicaxons at releases neurotransmitters at post specific targetorgans mostlyNE sometimes Ach Sympathetic Postganglionic Axons Ganglionicneurons insteadof synaptic terminals AXONTERMINALS formbranchingnetworks of telodendria formsympatheticvaricosities d swollensegmentpacked w neurotransmittervesicles passnearsurface of effectorcells nospecialized postsynaptic membrane membrane receptors on surface of targetcells releaseNE at mostvaricosities someganglionicrewons adrenergicneuron releaseAch sympatheticActivation activates entire sympathetic division during crisis changeactivities of tissues organsby releasingNE at peripheralsynapses targetingspecificeffectors distributing E NE throughoutbody in bloodstream entiredivision responds controlled sympatheticcenters in hypothalamus by changescausedby sympathetic activation increasedalertness stimulates reticularactivating system of feelings energy euphoria changes in breathing pons medulla elevation in muscletone mobilization of energyreserves Parasympathetic Division Anatomy of parasympatheticdivision pathwaysarisefrom brain sacralregions craniosacral division long preganglionic short postganglionicfibers general pathway cell bodies of pre in ganglionic neurons midbrain pons medulla or sacralsegments 52 54 ganglionicfibers travelthrough cranial or sacral nerves pre end in terminal near targetorgan ganglia in synapse w postganglionic neurons in ganglia fiberscover short distance toorgans  controlviscera structuresin hea 1 15 1 1Mirgainization a anatomy of parasympathetic division chic cavities ganglionicfibersleave brain as components of cranial nerves pre X vagus of all parasympathetic afflow ganglionicfibers leavespinal cord at sacrallevel pre heYes neuromuscular neuroglandularjunctions small narrowsynapticclefts both ALL release Ach as neurotransmitter fregarang.inEnerons effects of stimulation are shortlived inactivated inactivated by cholinesterase acetylcholinesterase by in surroundingtissues 5 responses to increased parasympathetic activity 1 decreased metabolic rate 2 decreased heart rate BD 3 increased secretion digestiveglands 4 increased by salivary bloodflow m digestivetract motility 5 urination defecation stimulation Enteric plexus enteric nervous system nervous network of digestivetract 3ʳᵈ division ofANS 500 mil neurons in digestivetract doesnot arise from spinal cordor ANS unlike rest of ANS innervates smooth muscle glands own ganglia reflex arcs regulatesmotility of digestiveorgans digestivefunctionalso regulatedby parasympathetic sympathetic Neurotransmitters Their receptors Divisions of ANS haveapp effects on organ because sympathetic parasympatheticsecrete different neurotransmitters NE Ach receptors on target cells 7 59 5merdstafferent fronts Bond Ach secretedby all vary Forclassesanreceptors preganglionic neurons both divisions in postganglionicparasympatheticneurons by  2 categories of cholinergic receptors 1 muscinaric receptors found on cardiac smoothmuscle gland cells w cholinergic innervation act through 2ⁿᵈ messenger systems Achexcites intestinal smoothmuscle but inhibits cardiac muscle example of receptorsubtypes 2 Nicotinic receptors found on post ganglionic neuron cell bodies in autonomic ganglia on cells of adrenal medulla neuromuscular junction of skeletal muscle fibers binding of ACh alwaysexcitatory openligand gated Nat channelsproduce EPSPs Dangerous environmental toxins produce exaggerated uncontrolled responses Nicotine binds to nicotinicreceptors in 5 and PS ganglion cells targets autonomic ganglia skeletal neuromuscularjunction signs symptoms of poisoning tachycardia vomitingdiarrhea highBP rapidheartrate sweating salivation convulsions Muscarine toxin producedfromsome poisonous mushrooms targets PS neuromuscularglandular junctions signs symptoms of toxicity salivation vomiting diarrhea constriction of respiratory passages lowBP slow heart rate bradycardia Norepinephrinesecretedbynearly all sympatheticpostganglionicneuron secretedby adrenergic fibers NE receptors calledadrenergic receptors 2 categories of adrenergic Ne E receptors 1 Alpha adrenergic usuallyexcitatory qty twosubclasses use different 2ⁿᵈmessengers 2 Beta adrenergic usuallyinhibitory 1sB twosubclasses w diff effects but both actthrough CAMP  Alpha 1 more common receptor releases intracellularcalcium ionsfromreserves in ER has excitatoryeffect on target cell A SEEcAMPlevels in cytoplasm inhibitoryeffecton cell helpscoordinatesympathetic parasympathetic activities Beta 1 increases metabolic activity increaseactivityof skeletal cardiac muscle Beta 2 triggers relaxation ofsmoothmusclesalongrespiratorytract Beta 3 leads to lipolysis breakdownoftriglycerides in adipocytes cholinergic sympathetic terminals innervatesweatglands bloodvessels of skeletal muscles brain stimulate sweat glandsecretion dilate bloodvessels toskeletalmuscles brain Autonomiceffects on glandular secretion are often an indirectresultof theireffect on bloodvessels blood How secretion blood flow secretion sympatheticeffects tend to last longerthan PSeffects someANSfibersreleaseotherneurotransmittersthan ACh or NE encephalin substanceP nitric oxide Dual innervation mostviscerareceivenervefibersfrom both ps division S Antagonist effects opposeeach other Cooperativeeffects twodivisions act on differenteffectors to produceunifiedeffect control w at dual innervation DI not always necessary forANS to produceapp effects in organ regulationof bloodpressure routes of bloodHOW baselinesympathetic tonemaintainsvasomotor tone firing vasoconstriction state wseknfalcotimg.ch d  g Central control of Autonomic function ANS is regulated by several levels of CNS cerebral cortex limbic system emotions influence ANS b c connectionsbetween limbicsystem hypothalamus Hypothalamus containsnuclei for primitivefunctions hunger thirst sex midbrain pons medulla oblongata nuclei for cardiac vasomotorcontrol salivationswallowing sweating bladdercontrol pupillary changes spinal cord reflexes for defecation micturition Drugs Nervoussystem oldmedicine neuropharmacology studyof effect of drugs on nervoussystem late nasal bloodvessels sympathomimetics enhancesympatheticactivity betablockers stimulate receptors or increaseNErelease educe BP sympatholytics suppress sympatheticactivity blockreceptors or inhibit NE release Parasympathomimetics enhance parasympathetic effects Parasympatholytics suppressthem manydrugs act on neurotransmitters or their receptors in CNS prozac is SSRI blocksreuptake of serotonin montsamine MAO inhibitors block MAO to slow breakdownof caffeinecompetes w adenosine causessleepiness binding to itsreceptors by LESSON 20 3 kinds of muscletissue striations 1 skeletal voluntary movement Whether'sdormyo fibers 2 cardiac involuntary in heart 3 smooth involuntary organs systems all convertATP into mechanical energyof motion Muscularsystemrefersonlytoskeletalmuscles myology studyof muscularsystem characteristics of muscle cells 1 Excitability tochemical signalsstretch and electrical changes 2 localelectrical  c on thattravels alongthemusclefiber 3 Contractility shortenswhenstimulated 4 Extensibility capableof beingstretchedbetween contractions 5 Elasticity returnsto original lengthafterbeingstretched Skeletal muscle 6 functions of skeletal muscletissue 1 produceskeletal movement through somaticnervoussystem 2 maintainposture position body 3 supportsofttissues linepelviccavity abdominalwall 4 guardentries exits urethra 5 maintainbodytemperature contractions produceheat 6 storenutrients reserves muscleproteins can breakdown 1 fibrousconnectivetissue Endomysium surrounds each muscle fiber Perimysium bundles musclefibers into fascicles Epimysiumsurrounds entiremuscle theyattach continuous w collagen in tendons in bonematrix to 8 Endomysium thin sleeveof looseconnectivetissuearoundeachfiber fggjftd provides chemical environmentfor musclefiber nerveending gfffgep.pk Joplin nas mosque can meman no repair damage to msn.cn fpeypygyyna.name mama map mm mm mm mmmm carriesnerves bloodvessels stretchreceptors Epimysium fibroussheathsurroundingentiremuscle blends w fascia sheetofconnectivetissue between muscle and deeper connectivetissues components of a muscle fiber Sacrolemma plasmamembraneof musclefiber surrounds the sacroplasm cytoplasm of musclefiber insidesacroplasm fibrils longproteincordsoccupyingmostof sacroplasm myo Glycogen carbstored to provide energy for exercise myoglobin redpigmentedprotein bindsonto oxygen providessome needed  y Sauroplasmic reticulum smooth ERthatforms a network around each mystibril stores calcium in cell terminal cisterns dilatedendsacs of SR which cross the musclefiberfrom oneside to theother calciumreservoirforcontraction transverse T tubules tubularinfoldings of thesacrolemmawhich penetrate through cell emerge on other side funnels action potentials generated in cell to terminal cisterns each T tubule has 2 terminal cisterns w it on eitherside formsstructurecalled the triad myoblasts stem cells that fused to formeach muscle fiber in earlydevelopment each contributingonenucleus skeletalmusclecells are multinucleated myosatellite cells unspecialized myoblasts that remain between muscle fiber endomysium regeneration myo filaments myofibrilscomposed ofthese 3 kinds of myofilaments motorprotein 1 Thickfilaments madeofseveralhundredmyosin molecules eachmolecule shapedlikegolfclub two chains intertwined toform a shaft like tail doubleglobularhead barezone w no headsin middle 2 Thinfilaments composed of 3diff proteintypes fibrous f actin 2 intertwinedstrands of globular 6 actin subunits each w active site that can bind to head of myosin F actin heldtogether protein strand nebulin that by runs along length of strand tropomyosin regulatoryprotein that blocks active sites on 6 actin subunits troponin small calciumbindingprotein on each tropomyosin mol 3 Elastic filaments made of huge springyprotein called titin run throughcore of thick filament anchor it to Z disc M line help stabilize a position thickfilament prevent overstretching provide recoil  ofcalciumfromSRintosacroplasm contractile proteins myosin actin regulatoryproteins tropomyosin troponin troponinchangesshape moves tropomyosin off theactivesites on actinwhichthenallows the myosinheadto bindontoactin striations Sacromeres striations are alternating A band I bands A band darkband Itband not as dark middleof A band thickfilaments only M line dark transverseproteinin middle of it band 1 band lightband onlythin filaments Zdisc t line proteincomplexthatprovidesanchoragefor thin filaments elasticfilaments Sacromere segmentfrom Z disc to Z disc contractileunit musclecells shorten b c theseshorten t discs pulledclosertogetheras thick thinfilamentsslide pasteachother zoneof overlap is area of A bandminus it band zone increases duringmuscle contraction motor Neurons and motor units Skeletal muscle cannot contract unless stimulated by a nerve if nerveconnectionssevered or poisoned a muscle is paralyzed andmay wasteaway denervationatrophy Skeletal musclecells are served somaticmotorfibers by somaticmotorneurons lead toskeletal muscle motor unit one nervefiberand all musclefibers innervated it Musclefibers of onemotorunit by dispersedthroughmuscle contract in unison longtermcontraction motorunits taketurns Aug motor unit contains200musclefibersdistributedacross as many as 100fascicles small motorunits provide a fine degree of control eve handmuscles Largemotorunitsprovidemorestrengththancontrol quadricepsfemoris  Neuromuscular Junction Synapse pointwhere a nerve fibermeets its targetcell whentarget cell is a muscle fiber thesynapse is also called a neuromuscularjunction or motorend plate Eachterminalbranch within NMJformsseparatesynapse with themusclefiber consisting of Axon terminal swollen end of nerve fiber contains synapticvesicles containing ACh Synaptic cleft narrow gapbetween axon terminal sacrolemma structure function of NMJ muscle cell sacrolemma has millions of Achreceptor postsynaptic membrane folds of saurolemmaincrease SA maximize of Ach receptors lackof receptorscausesweakness in the diseasemyastheniagravis TheNMJcontains acetylcholinesterase musclefibers nerve cells are electricallyexcitablecells membranes exhibitvoltagechanges in response to stimulation Electrophysiology study of electrical activity of cells ICF contains morenegativeions thanECF membrane is polarized contains net charge in resting cell plasmamembrane is polarized w resting membranepotential RMP in stimulated cell Not flowsdown electrochemical gradient causing depolarization of membrane kt Hows at causing repolarization of membrane Yfential Neuromuscular Toxin Paralysis Toxinsinterfering w synaptic function can paralyzemuscles somepesticides contain cholinesterase inhibitors bindto acetylcholinesterase preventfrom degrading Ach spasticparalysis stateof continual contraction of muscles Tetanus is a form of spasticparalysis caused clostridium tetani by Tetanusblocks glycine release in the spinal cord causes overstimulation and spasticparalysis of muscle it Flaccidparalysis statewheremuscles are limp cannotcontract Botulism food caused neuromuscular mg by