BIOL 260-(Ch 15 ANS)-F19.ppt - The Autonomic Nervous System...

This preview shows page 1 - 9 out of 36 pages.

The Autonomic Nervous System1
The Autonomic Nervous System2Fight-or-Flight?Unless otherwise indicated,The Autonomic Nervous System (Special Senses)Lecture Slides by YancyAquino for Skyline College are derivative ofOpenStax A&P Instructor Resourcesand are licensedCC BY.
Central nervous system (CNS)Peripheral nervous system (PNS)Motor (efferent) divisionSensory (afferent)divisionSomatic nervoussystemAutonomic nervoussystem (ANS)SympatheticdivisionParasympatheticdivision3ANS consists of motor neurons that:Innervatesmoothandcardiac muscleandglandsOperate via subconscious controlOther namesInvoluntary nervous systemGeneral visceral motor system
The two systems differ inEffectorsEfferent pathways (and their neurotransmitters)Target organ responses to neurotransmittersEffectorsSomatic nervous systemSkeletal musclesANSCardiac muscle; Smooth muscle; Glands4
Skeletal muscleCell bodies in centralnervous systemPeripheral nervous systemEffect++EffectororgansAChAChSmooth muscle(e.g., in gut),glands, cardiacmuscleGanglionAdrenal medullaBlood vesselAChAChAChNEEpinephrine andnorepinephrineAcetylcholine (ACh)Norepinephrine (NE)GanglionHeavily myelinated axonLightly myelinatedpreganglionic axonLightly myelinatedpreganglionic axonsNeuro-transmitterat effectorUnmyelinatedpostganglionicaxonUnmyelinatedpostganglionic axonStimulatoryStimulatoryor inhibitory,dependingon neuro-transmitterandreceptorson effectororgansSingle neuron from CNS to effector organsTwo-neuron chain from CNS to effector organsSOMATICNERVOUSSYSTEMAUTONOMIC NERVOUS SYSTEMPARASYMPATHETICSYMPATHETIC5
Somatic nervous systemthick, heavily myelinated somatic motor fibermakes up each pathway from the CNS to themuscleANS pathway is a two-neuron chain1.Preganglionic neuron(in CNS) has a thin,lightly myelinated preganglionic axon2.Ganglionic neuronin autonomic ganglion hasan unmyelinated postganglionic axon thatextends to the effector organ6
Somatic nervous systemAll somatic motor neurons release AChEffects are alwaysstimulatoryANSPreganglionic fibersrelease AChPostganglionic fibersrelease NE (secreted bymost sympathetic fibers) or ACh (secreted byparasympathetic fibers) at effectorsEffect isstimulatoryorinhibitory, dependingon type of receptors7
1.Sympathetic division:Mobilizes the body during activity; is the“fight-or-flightsystemPromotes adjustments during exercise, or whenthreatenedBlood flow is shunted to skeletal muscles and heartBronchioles dilate; Liver releases glucose2.

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 36 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Fall
Professor
tonini
Tags

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture