Chapter 35 - The Nervous System - Home Page of the Cougars!

Living Environment - Chapter 35 - TheNervous SystemHomeostasis & Feedback• Homeostasis is a Feedback System like the thermostat in aroomThermostat senses tempchange and switches offheating system7Room temperatureincreasesFeedbackRegulationRoom temperaturedecreasesThermostat senses tempchange and switches onheating systemHomeostasis, Feedback & Body Temp 8• Homeostasis in your body uses Feedback Systems• Heat loss and heat production are carefully balancedMaintains 98.6°F (37°C)Controlled by Hypothalamus in the brainMonitors skin temp and core organ temp– Shivering is how the body raises temp when youget too cold– A signal from Hypothalamus to muscles in skinWhen you get too hot, the Hypothalamus sends asignal to sweat glands– Evaporation of sweat cools the body• Homeostasis in your body is controlled by the BrainHomeostasis, Feedback & Glucose• Homeostasis in your body uses Feedback Systems• GlucoseWhen you eat, glucose (sugar) from food enters yourbloodHigh blood glucose triggers release of the hormoneinsulin from the pancreasControlled by Hypothalamus in the brainInsulin causes blood sugar to be absorbed into liver,muscle and fat (excess) cellsIf blood glucose gets too low, the pancreas releases thehormone glucagon, which causes sugar to be released• Homeostasis in your body is controlled by the Brain93

Living Environment - Chapter 35 - TheNervous SystemChapter 35 Vocab131. Axon2. Central Nervous System3. Cerebellum4. Cerebrum5. Dendrite6. Homeostasis7. Hypothalamus8. Neuron9. Neurotransmitter10.Sensory Receptor11.Synapse12.Thalamus13.Tympanic MembraneDefinitions are due in 2 days !!Section 1: Neurons14Objectives1. Identify the role of neurons2. List 3 types of neurons3. Describe the structure of a neuron4. Define a synapse and summarize theevents that occur there5. Define a neurotransmitter and list 4 types• Cells that transmitinformationNeurons: Nerve Cells15• Enable all activitiesMovement,perception, thought,emotion, and learning• Interconvert betweenelectrical signals(impulses) and chemicalsignalshttp://www.sprechstundem21.unibe.ch/neurons-1.jpg5

Living Environment - Chapter 35 - TheNervous System• DendritesExtend from cell bodyReceive info fromother cellsRelays info to the CellBody• Cell BodyRelays info to otherparts of a neuronStructure of a Neurondendrites cell body axon• AxonLong extension of the cellConducts nerve impulseto a Synapse• Synapse – not part of NeuronAxon terminalThe place where a signaltravels to a new cellCan be a gland, muscleor other neuronsynapse19http://faculty.washington.edu/chudler/fillin1.html• Neurons do not touch• There is a small gapbetween the axonterminal and the nextneuron (or muscle orgland)This gap is called theSynapse• A signal crosses thesynapse whenNeurotransmitters arereleased from an axonThe Synapse• NeurotransmittersChemicals (mostly aminoacids or proteins) that crossthe synapse to stimulate thenext cellLeft-overneurotransmitters areremoved to prevent overstimulationNeurotransmitters include:DopamineAcetylcholineGlutamateSerotonin20A Nerve Impulse• Nerve impulses are transmitted from dendrite to axonAlong a nerve by sodium and potassium ions – electricalAcross a synapse by Neurotransmitters – chemical21http://www.kankada.com/neurons_mac.shtmlsynapseneurotransmitters7

Living Environment - Chapter 35 - TheNervous SystemSynapse: “The Space Between”22http://www.txtwriter.com/Backgrounders/Drugaddiction/synapse.jpgReview Questions231. What are the three main parts of a neuron?2. What is the name of the insulation around some neurons?3. In which direction does an impulse travel through aneuron?4. What is the space between neurons called?5. What molecule crosses the synapse and stimulates thenext cell?Section 2: The Nervous System24Objectives1. List the 2 primary divisions of the nervous systemand describe their functions2. Identify the 5 key areas of the brain and list theirkey functions3. Understand the function and structure of thespinal cord4. List the 2 main parts of the Peripheral NervousSystem5. Identify the functions of the Somatic NervousSystem and the Autonomic Nervous System8

Living Environment - Chapter 35 - TheNervous SystemThe Nervous System25• There are 2 primary divisions of the HumanNervous System1.The Central Nervous System (CNS)The Brain and Spinal CordThe control center for the body – the CPU2.The Peripheral Nervous System (PNS)Receives and transmits info from the worldto the brainThe Central Nervous System (CNS)26CerebrumThalamusPinealglandHypothalamusPituitary glandPonsMedulla oblongataCerebellumSpinal cordThe Central Nervous System (CNS)• There are 5 key parts of the Brain1. Cerebrum - the largest part of brainLearning, memory, perceptionand intelligence, personality,Cerebrumdecision-makingAlzheimer’s DiseaseRight and left hemispheres– Right brain” and “left brain”– Right brain controls left half of body– Left brain controls right half of bodyCerebral cortex – a thin outer layer– Sensory and motor processing– Folds on surface add surface area279

Living Environment - Chapter 35 - TheNervous SystemPhineas Gage28• In 1860, a RR worker had ametal rod driven thru hisskull• He lost an eye and sufferedsevere personalitychanges, but was still ableto speak and walk• This accident was the firstevidence for the role of theCerebrum on personalityand behaviorhttp://en.wikipedia.org/wiki/File:Phineas_gage_-_1868_skull_diagram.jpghttp://www.sciencemuseum.org.uk/exhibitions/brain/images/1-1-8-3-1-1-1-0-0-0-0.jpgThe Cerebellum & Brain Stem2. CerebellumBalance, posture,and movementParkinson’s Disease3. Brain StemConnects brain andspinal cordPonsBreathingMedullaOblongata Heart rate &BP,swallowingPonsMedullaoblongataSpinal cord29CerebellumThalamus & Hypothalamus4. ThalamusThe relay station for sensory impulses305. HypothalamusControls body temp, water, glucose, metabolismHomeostasisHunger, pain, and pleasureHypothalamusThalamus10

Living Environment - Chapter 35 - TheNervous SystemThe Spinal Cord31• The Spinal CordInfo travels from bodyup spinal cord to brain,brain sends message back31 pairs of nerves branchto body from hereControls ReflexesQuick automaticresponse to a stimulusSneezing, blinkingDamage to disks causespinched nervesSciaticahttp://www.sci-recovery.org/images/vertebraeandspinalcord.jpgReview Questions321. What is the Central Nervous System?2. Name the 5 main parts of the brain.3. What part of the brain controls your personality?4. Where are the Reflexes found?The Peripheral Nervous System (PNS) 33• Made of 2 parts1.The Somatic Nervous System2.The Autonomic Nervous System• The PNS connects CNS to rest ofbody1.Somatic Nervous System (SNS)Conscious muscle controlSkeletal musclesCritical for some reflexes alsohttp://www.thebrain.mcgill.ca/flash/i/i_01/i_01_cr/i_01_cr_ana/i_01_cr_ana_2a.jpg11

Living Environment - Chapter 35 - TheNervous SystemReview Questions1. Where in the brain is all Sensory Information processed?432. What do Rod and Cone cells do?3. What is another name for the Tympanic Membrane?4. What type of cells are nasal Sensory Receptors found in?5. What type of sensory receptor is involved in detecting:a. Temperatureb. Touch and soundc. Lightd. Taste and smellAddiction• Drugs alter the normal functioning of neurons andsynapsesThey can’t functionunless the drug is presentToleranceIncreasing amountsof the drug are neededto achieve the same“high”WithdrawalEmotional andphysical symptomscaused by stoppinguse of the drug44• Addictive SubstancesStimulantsCaffeineNicotineCocaineMethamphetamine– CrankDepressantsAlcoholOpiatesBarbituratesCodeineCocaine Addiction:Changes in Neuron Function45• Stimulantslike cocainecausehyperactivityat synapses,which is whythey stimulatehttp://www.utexas.edu/research/asrec/drugs.gif15