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Chapter 35 “The Chapter 35 “The Nervous System Nervous System 35.1 “The Human 35.1 “The Human Nervous System” Nervous System” Objective: Objective: List the 3 main structures of a neuron List the 3 main structures of a neuron Describe a Nerve Impulse Describe a Nerve Impulse

Chapter 35 “The Nervous System” 35.1 “The Human Nervous System”35.1 “The Human Nervous System” Objective:Objective: –List the 3 main structures of a neuron

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Text of Chapter 35 “The Nervous System” 35.1 “The Human Nervous System”35.1 “The Human Nervous...

  • Chapter 35 The Nervous System35.1 The Human Nervous SystemObjective:List the 3 main structures of a neuronDescribe a Nerve Impulse

  • NeuronsBasic unit of the N.S.Carry messages in the form of electrical impulsesMade up of:cell body - largest partdendrites - carry impulses toward the cell bodyaxon - carries impulse away from cell bodyaxon terminal sends impulse to next neuron

  • Three Types of NeuronsSensory : body to brainMotor : brain to bodyInterneurons : connect sensory & motor neurons in brain and spinal cord

  • Nerve ImpulseBegins when a neuron is stimulated by env. or another neuronResting Potential: a neuron without an impulseInside of neuron is more negative than outsideAction Potential: change in chargeInside of neuron becomes more positive

  • Inside is negativeInside becomes positiveDomino effect passes action potential down axonInside returns to negativeResting Potential

  • MyelinMyelin sheath: fatty layer which insulates axonSpeeds up impulse

  • SynapseSynapse: The space between the axon terminal of one neuron and the dendrites of the next neuron.Axon terminal releases neurotransmitters.

  • 35.2 Organization of the N.SObjective:Distinguish between the Central Nervous System & the Peripheral Nervous System.

  • The Central Nervous SystemBrainSpinal Cord

  • The BrainFour lobes, two halvesMajor regions:Cerebrum conscious activity/thoughtCerebellum coordinates movementBrain stem connect brain and spinal cord, controls many involuntary fxnsThalamus receives sensory messagesHypothalamus controls primitive needs and emotions

  • The Brain

  • The Spinal Cord31 pairs of nerves branch off

    Controls reflex arc

  • Peripheral Nervous SystemAll nerves outside of brain and spinal cordSensory receives internal and external stumuliMotor controls muscles and glands

  • Peripheral Nervous SystemMotor DivisionSomatic NS controls all voluntary activityAutonomic NS involuntary activitySympathetic controls body during times of stressEx - speeds up heart rateParasympathetic controls body normally, returns body to normal state after stressEx slows heart rate

  • N.S. Concept Map

  • Chapter 35.3 The SensesObjective:List and discuss the 5 senses.

  • The Five SensesSight, Sound, Taste, Touch, SmellThere are 5 general categories of sense receptors.Pain receptorsThermoreceptors - temperatureMechanoreceptors touch, soundChemoreceptors - chemicalsPhotoreceptors - light

  • VisionPhotoreceptors in retinaRods detect lightCones detect color

  • HearingAcoustic Receptors: a special type of mechanoreceptor.Respond to sound (disturbance of air)Found in inner ear. Semicircular canals: fluid filled tubes that help you maintain your balance

  • The EarSemicircular canals

  • Smell & TasteChemoreceptorsRespond to taste & smell (chemical stimuli)Found in tongue, roof of mouth, nasal cavity.