Chapter 10Efferent Division of the Peripheral Nervous SystemFigure 11.Antagonistic Control of the Autonomic DivisionPowerPoint PresentationAutonomic PathwaysSlide 7Vagus NerveSlide 9NorepinephrinePostganglionic Autonomic NeurotransmittersAdrenergic ReceptorsParasympatheticAdrenal MedullaComparison of Sympathetic and Parasympathetic BranchesEfferent DivisionsSlide 17Somatic Motor DivisionSlide 19Neuromuscular JunctionSlide 21Slide 22Slide 23Chapter 10•The autonomic division•The somatic motor division© 2013 Pearson Education, Inc.Efferent Division of the Peripheral Nervous System•Somatic motor neurons–Control skeletal muscles–Mostly voluntary•Autonomic neurons–Control smooth and cardiac muscle, many glands, lymphoid and some adipose tissues–Mostly involuntary–Sympathetic branch is fight-or-flight–Parasympathetic branch is rest-and-digest–Works with endocrine and behavioral state systems to maintain homeostasis© 2013 Pearson Education, Inc.Figure 11.THE AUTONOMIC DIVISIONHomeostasis is a dynamic balancebetween the autonomic branches.Rest-and-digest:Parasympatheticactivity dominates.Fight-or-flight:Sympathetic activitydominates.ParasympatheticSympatheticAntagonistic Control of the Autonomic Division•Most internal organs are under antagonistic control–One autonomic branch is excitatory, and the other branch is inhibitory–Example:–Effector organ: heart–Sympathetic response increases heart rate–Parasympathetic response slows rate© 2013 Pearson Education, Inc.*Hormonal epinephrine only**All parasympathetic responses are mediated by muscarinic receptors.SYMPATHETIC RESPONSEADRENERGICRECEPTORPARASYMPATHETIC RESPONSE **EFFECTORORGANPupil of eyeDilatesConstrictsSalivaryglandsMucus, enzymes Watery secretion and 2HeartSlows rateIncreases rateand force ofcontraction1 2Arteriolesand veinsConstrictsDilates2*, 2Lungs BronchiolesdilateBronchiolesconstrictDigestivetractDecreasesmotility andsecretionIncreasesmotility andsecretionExocrinepancreasDecreasesenzymesecretionIncreasesenzymesecretionEndocrinepancreasInhibits insulinsecretionStimulates insulin secretionAutonomic PathwaysAutonomic pathways consist of two neuronsthat synapse in an autonomic ganglion.PreganglionicneuronPostganglionicneuronAutonomicganglionTargettissueCNSSYMPATHETIC PARASYMPATHETICHypothalamus,Reticular formationPonsMedullaSpinalcordSympathetic chainFIGURE QUESTIONS1. Name the regions of the CNS where the two branches originate.2. Describe where the ganglia for the two branches are located (relative to the spinal cord).3. What is an advantage of having ganglia in the sympathetic chain linked to each other?SympatheticParasympatheticKEYCo1L1S1T1C123456782345678910111223452345PelvicnervesUterusTestesPenisUrinary bladderKidneyAdrenal medullaPancreasIntestinesStomachLiverGanglionEngorgementand secretionsStimulatescontractionIncreasesrenin secretionInhibitsdigestionRelease enzymesand insulinIncreases motilityand secretionIncreasesmotility andsecretionDecreases enzymes and insulinInduces erectionRelease of urineInduces ejaculationRelaxes bladdersecretes catecholaminesInhibits digestionInhibits digestionIncreases bilesecretionRelaxesairwaysIncreases heart rateand contractilityMucus and enzymessecretedPupil dilatesPupil constrictsWatery secretionSlows heart rateConstricts airwaysLungsHeartSalivary glandsEyeGanglionHypothalamus,Reticular formationPonsMedullaSpinalcordVagusnerveVagus Nerve•Contains about 75% of all parasympathetic fibers•Sensory information from internal organs to brain•Output from brain to organs© 2013 Pearson Education, Inc.Parasympathetic pathwaysuse acetylcholine.Sympathetic pathwaysuse acetylcholine andnorepinephrine.FIGURE QUESTIONSCNS CNSAChNicotinicreceptorAutonomicganglionNorepinephrineTarget tissueAChMuscarinicreceptorAdrenergicreceptor1. Identify all: - cholinergic neurons - adrenergic neurons - preganglionic neurons - postganglionic neurons2. Which pathway will have longer preganglionic neurons? (Hint: See Fig. 11.5.)T TNorepinephrineNE is metabolized bymonoamine oxidase (MAO).NE can be taken back intosynaptic vesicles for re-release.NE is removed from the synapse.Receptor activation ceases whenNE diffuses away from the synapse.NE binds to adrenergicreceptor on target.Ca2 entry triggersexocytosis of synaptic vesicles.Depolarization opensvoltage-gated Ca2 channels.Action potential arrives atthe varicosity.Norepinephrine (NE) release and removal at a sympathetic neuroeffector junctionAxon varicosityMAOTyrosineAxonExocytosisNEActionpotentialVoltage-gatedCa2 channelCa2NEDiffuses awayBloodvesselAdrenergicreceptorResponseTarget cellActive transportGPostganglionic Autonomic NeurotransmittersAdrenergic ReceptorsParasympathetic•Acetylcholine•***Muscarinic receptors–G protein–coupled–Second messenger pathways–At least five subtypes© 2013 Pearson Education, Inc.Adrenal Medulla•Neuroendocrine tissue•Associated with the sympathetic branch•Primary neurohormone is epinephrine–Secreted into the blood© 2013 Pearson Education, Inc.Spinal cordPreganglionicsympatheticneuronAChAdrenal medullaThe chromaffincell is a modifiedpostganglionicsympatheticneuron.Epinephrine is aneurohormone thatenters the blood.To targettissuesBlood vesselComparison of Sympathetic and Parasympathetic Branches*Efferent DivisionsAUTONOMIC PATHWAYSParasympathetic PathwaySympathetic PathwayAdrenal SympatheticPathwayAutonomic targets:CNSCNSCNSAChAChNicotinic receptorNicotinic receptorGanglionMuscarinicreceptor receptor2 receptor1 receptorEEAdrenal medullaAdrenal cortexBlood vesselKEYFIGURE QUESTIONS• Smooth and cardiac muscles• Some endocrine and exocrine glands• Some adipose tissueUsing the figure, compare: (a) number of neurons in somatic motor and autonomic pathways (b) receptors on target cells of somatic motor, sympathetic, and parasympathetic pathways (c) neurotransmitters used on target cells of somatic motor, sympathetic, and parasympathetic pathways (d) receptor subtypes for epinephrine with subtypes for norepinephrineACh  acetylcholineE  epinephrineNE  norepinephrineAChNEEfferent DivisionsComparison of Somatic Motor and Autonomic DivisionsSOMATIC MOTOR AUTONOMICNumber of neurons in efferent path 1 2ACh/muscarinic or NE/- or -adrenergicACh/nicotinicNeurotransmitter/receptor atneuron-target synapseTarget tissue Skeletal muscle Smooth and cardiac muscle; some