揚州大学Chapter 10. Nervous SystemAll figures are from internet, textbooks and papers, all rights reserved to the originalauthors
Chapter 10. Nervous System All figures are from internet, textbooks and papers, all rights reserved to the original authors
ParietalCeritralobesulcusOutlineOocipitalotyOverviewoftheNervousSystemaStructure.andFunctionofNeuronsemoSynapsesControl of BodyMovementSection DSpintrmsrootDorstAutonomic Nervous Systemlerv Higher Function of Nervous SystemVert
Outline • Overview of the Nervous System • Structure and Function of Neurons • Synapses • Control of Body Movement • Section D Autonomic Nervous System • Higher Function of Nervous System
Overview of the Nervous SystemPNSCNSBrainMCAT-Review.orgSensorSensory (afferent)Spinal cordSomatic/visceral/specialsensoryEffectorMotor(efferent)SomaticSkeletalMusclesSympatheticInvoluntaryAutonomicMusclesandOrgansParasympatheticEntericmcat-review.org
Overview of the Nervous System mcat-review.org Somatic/visceral/special sensory Enteric
Comparison of Autonomic and Somatic Nervous SystemSomatieAutonomicConscious orvolun-Functionswithout conscious awareness(involuntary)taryregulationFibersdonotsynapseFibers synapse once at a ganglion afterafterthey leavethetheyleavethe CNs (two-neuronchain).CNS (single neuronMotor control.fromCNStoeffectororgan).Innervates skeletalInnervates smoothmuscle,cardiacmus-musclefibers,alwayscle,and glands: either stimulates orinhibitsstimulatory01.edu-cdn.com
Comparison of Autonomic and Somatic Nervous System 01.edu-cdn.com
The Autonomic Nervous SystemANS, part of the peripheral nervous system that acts as acontrol system,controls visceralfunctions- a two-neuron pathway: preganglionic/postganglionic-senses viscera and skin signals and transmitthe signals into brainandspinalcord- preganglionic neurons: cell body in CNS while synapse at PNS(ganglion)- postganglionic neurons: terminates on effector organsTwo subsystems: sensory (afferent) and motor (efferent)Canbedividedinto theparasympatheticnervous system(PSNS) and sympathetic nervous system (SNS)
The Autonomic Nervous System • ANS, part of the peripheral nervous system that acts as a control system, controls visceral functions - a two-neuron pathway: preganglionic/postganglionic - senses viscera and skin signals and transmit the signals into brain and spinal cord - preganglionic neurons: cell body in CNS while synapse at PNS (ganglion) - postganglionic neurons: terminates on effector organs • Two subsystems: sensory (afferent) and motor (efferent) • Can be divided into the parasympathetic nervous system (PSNS) and sympathetic nervous system (SNS)
Structural Characteristics of the AutonomicNervous SystemTwo neurons: preganglionic and postganglionic SNS: short preganglionic and long postganglionic neuronsPsNS: long preganglionic and short postganglionic neuronsSNS:fibers from T1-L2 of the spinal cordPsNS:fibersformbrainstemandS2-S4 ofthespinal cord
Structural Characteristics of the Autonomic Nervous System • Two neurons: preganglionic and postganglionic • SNS: short preganglionic and long postganglionic neurons PSNS: long preganglionic and short postganglionic neurons • SNS: fibers from T1-L2 of the spinal cord PSNS: fibers form brain stem and S2-S4 of the spinal cord
Structural Characteristics of the Autonomic Nervous Systemsns:synapseinsideand outside thesympathetic trunk,or directlycontroladrenalmedullaPsNS:synapse with peripheral ganglia (near or directly on the effectororgan)Skin,muscle bloodvessels,sweat glands,hair shaft muscle,adrenalmedulla,andkidneyonlycontrolledbySNsSNs:highdivergency(pre→post)→widereffects
Structural Characteristics of the Autonomic Nervous System • SNS: synapse inside and outside the sympathetic trunk, or directly control adrenal medulla PSNS: synapse with peripheral ganglia (near or directly on the effector organ) • Skin, muscle blood vessels, sweat glands, hair shaft muscle, adrenal medulla, and kidney →only controlled by SNS • SNS: high divergency (pre→post) → wider effects
The Svmpathetic Trunk(a)SYMPATHETICCHAIN GANGLIASpinalnervePreganglionicAutonomic ganglion ofrightsympatheticchainneuronAutonomicganglionInnervatesofleftsympatheticchainvisceraleffectorsviaspinalnervesWhiteramusSympatheticnerveGanglionic(postganglionicneuronfibers)GrayramusInnervatesvisceralorgans in thoraciccavity viaKEYsympatheticnervesPreganglionicneuronsGanglionicneuronsclassconnection.s3.amazonaws.com
The Sympathetic Trunk classconnection.s3.amazonaws.com
TheAutonomicParasympathetic divisionSympatheticdivisionNervousSystemBrairEyeDilatesConstrictsSalivarypupilpupilglandsStimulatesInhibitssalivasalivaproductionproductionLungDilatesConstrictsbronchibronchiAcceleratesSlowsheartHearheartAdrenalglandSpinalStimulatescordLiverepinephrineStomachand norepinephrinereleaseStimulatesStimulatesPancreasstomach,glucose releasepancreas,and intestinesInhibitsstomach,Intestinespancreas,and intestinesBladderStimulatesInhibitsurinationurinationPromotesPromotesejacu-erectionoflationandvaginalGenitaliagenitalscontractionsCopyright2005 Pearson Education, Inc. Publishing as Pearson Benjamin Cummings. All rights reserved
The Autonomic Nervous System
FunctionalCharacteristics of theAutonomicNervous SystemTonic control: low-frequency and continuous activityDualinnervation: many organs (heart, salivary glands)EffectsoftheSNsandPsNSareusuallyantagonistic,dependingonfunctionalstatesoftheeffectorsOverallregulationofphysiologicalfunctionsSNS:Fight-or-flight↑ heartrate,bloodpressure,+ bloodflowto the skeletal musclesheartandbrain,glucosereleasefrom liver,pupilsdilate,gastrointestinal tractactivity.+ bloodflowto theskinPSNS:Rest-or-digestpredominanthomeostaticfunctions
Functional Characteristics of the Autonomic Nervous System • Tonic control: low-frequency and continuous activity • Dual innervation: many organs (heart, salivary glands) • Effects of the SNS and PSNS are usually antagonistic, depending on functional states of the effectors • Overall regulation of physiological functions • SNS: Fight-or-flight ↑ heart rate, blood pressure, ↑ blood flow to the skeletal muscles, heart and brain, glucose release from liver, pupils dilate, ↓ gastrointestinal tract activity, ↓ blood flow to the skin • PSNS: Rest-or-digest predominant homeostatic functions