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Copyright © 2012 F.A. Davis Company Understanding Anatomy & Physiology Understanding Anatomy & Physiology A Visual, Interactive Approach A Visual, Interactive Approach Chapter 10 The Nervous System The Nervous System

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HH126/MED115 Anatomy/Physiology Chapter 10 PowerPoint

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Page 1: Chapter10 - Nervous Sytem

Copyright © 2012 F.A. Davis Company

Understanding Anatomy & PhysiologyUnderstanding Anatomy & PhysiologyA Visual, Interactive ApproachA Visual, Interactive Approach

Chapter 10

The Nervous SystemThe Nervous System

Page 2: Chapter10 - Nervous Sytem

Copyright © 2012 F.A. Davis Company

Understanding Anatomy & PhysiologyUnderstanding Anatomy & PhysiologyA Visual, Interactive ApproachA Visual, Interactive Approach

Divisions of the Nervous Divisions of the Nervous SystemSystem

Central nervous Central nervous systemsystem Consists of brain

and spinal cord

Peripheral nervous Peripheral nervous systemsystem Consists of nerve

network

Page 3: Chapter10 - Nervous Sytem

Copyright © 2012 F.A. Davis Company

Understanding Anatomy & PhysiologyUnderstanding Anatomy & PhysiologyA Visual, Interactive ApproachA Visual, Interactive Approach

Page 4: Chapter10 - Nervous Sytem

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Understanding Anatomy & PhysiologyUnderstanding Anatomy & PhysiologyA Visual, Interactive ApproachA Visual, Interactive Approach

NeurogliaNeuroglia

OligodendrocytesOligodendrocytes: Form myelin sheath Ependymal cellsEpendymal cells: Secrete cerebrospinal

fluid MicrogliaMicroglia: Perform phagocytosis AstrocytesAstrocytes: Form blood–brain barrier Schwann cellsSchwann cells: Form myelin sheath in

peripheral nervous system

Supportive cells of the nervous systemSupportive cells of the nervous system

Page 5: Chapter10 - Nervous Sytem

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Blood–brain barrierBlood–brain barrier

Formed as astrocytes wrap around capillaries

Protects brain from foreign substances

Page 6: Chapter10 - Nervous Sytem

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The most numerous of all glial cells are:

A.microglia.B.astrocytes.C.Schwann cells.D.ependymal cells.

Page 7: Chapter10 - Nervous Sytem

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Understanding Anatomy & PhysiologyUnderstanding Anatomy & PhysiologyA Visual, Interactive ApproachA Visual, Interactive Approach

Correct answer: B

Rationale:Astrocytes are pervasive throughout the brain and form the blood–brain barrier.

Page 8: Chapter10 - Nervous Sytem

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NeuronsNeurons Handle communication Three classes:

Sensory (afferent) neuronsSensory (afferent) neurons: Detect stimuli

InterneuronsInterneurons: Connect pathways Motor (efferent) neuronsMotor (efferent) neurons: Relay

messages

Page 9: Chapter10 - Nervous Sytem

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Neuron structureNeuron structureCell body

Dendrites

Axon

Myelin sheath

Nodes of Ranvier

Synaptic knob

Page 10: Chapter10 - Nervous Sytem

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Myelin sheathMyelin sheath

Peripheral Nervous SystemPeripheral Nervous System Central nervous systemCentral nervous system

Page 11: Chapter10 - Nervous Sytem

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Which neurons detect sensations (such as touch or heat) and relay information about the stimuli to the central nervous system?

A.Efferent neuronsB.InterneuronsC.Afferent neuronsD.Schwann cells

Page 12: Chapter10 - Nervous Sytem

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Correct answer: C

Rationale:Efferent neurons are motor neurons and relay messages from the brain to muscles and gland cells. Interneurons connect incoming sensory pathways with outgoing motor pathways in the central nervous system. Schwann cells form the myelin sheath.

Page 13: Chapter10 - Nervous Sytem

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Impulse conductionImpulse conduction Caused by an electrical current Membrane potentialMembrane potential: When ions with

opposite electrical charges are separated by a membrane

PolarizationPolarization: When a membrane has an excess of positive ions on one side and an excess of negative ions on the other

Page 14: Chapter10 - Nervous Sytem

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Impulse conduction: Step 1Impulse conduction: Step 1Resting potentialResting potential

Page 15: Chapter10 - Nervous Sytem

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Impulse conduction: Step 2Impulse conduction: Step 2DepolarizationDepolarization

Page 16: Chapter10 - Nervous Sytem

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Impulse conduction: Step 3Impulse conduction: Step 3Action potentialAction potential

Page 17: Chapter10 - Nervous Sytem

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Impulse conduction: Step 4Impulse conduction: Step 4RepolarizationRepolarization

Page 18: Chapter10 - Nervous Sytem

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Impulse conduction: Step 5Impulse conduction: Step 5Refractory periodRefractory period

<View animation of nerve impulse conduction in unmyelinated fibers>

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Impulse conduction: Impulse conduction: Myelinated fibersMyelinated fibers

<View animation on "Impulse transmission in myelinated fibers">

1.1.

2.2.

Page 20: Chapter10 - Nervous Sytem

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What is another term for nerve impulse?

A.RepolarizationB.Resting potentialC.DepolarizationD.Action potential

Page 21: Chapter10 - Nervous Sytem

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Correct answer: D

Rationale:

Repolarization is when the nerve cell restores its electrical balance in preparation for a new stimulus. Resting potential is when the neuron is resting but has the potential to react. Depolarization occurs as the membrane becomes more positive.

Page 22: Chapter10 - Nervous Sytem

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SynapsesSynapses

<View animation on "Synapses">

Page 23: Chapter10 - Nervous Sytem

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Spinal Spinal cordcord

Cervical

Thoracic

Lumbar

Sacral

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Structure of the spinal cordStructure of the spinal cord

Gray matter

White matter

Epidural space

Central canal

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Attachment of spinal nervesAttachment of spinal nervesDorsal nerve root

Ganglion

Ventral nerve root

Spinal nerve

Pia mater

Subarachnoidspace

Arachnoid mater

Dura mater

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Spinal tractsSpinal tracts

Dorsal column

Spinocerebellar tract

Spinothalmic tract

Corticospinal tracts

Extrapyramidal tractsExtrapyramidal tracts

Page 27: Chapter10 - Nervous Sytem

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Understanding Anatomy & PhysiologyUnderstanding Anatomy & PhysiologyA Visual, Interactive ApproachA Visual, Interactive ApproachSpinaSpina

l l nervenervess

• Relay information from spinal cord to rest of body

NerveFascicle

Page 28: Chapter10 - Nervous Sytem

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Spinal Spinal nervesnerves

8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal

Cervical plexus

Brachial plexus

Lumbar plexus

Sacral plexus

Page 29: Chapter10 - Nervous Sytem

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Somatic reflexesSomatic reflexes

<View animation on "Somatic reflexes">

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Page 30: Chapter10 - Nervous Sytem

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Bundles of axons within the white matter that serve as routes of communication to and from the brain are called:

A.ganglions.B.fascicles.C.tracts.D.plexuses.

Page 31: Chapter10 - Nervous Sytem

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Correct answer: C

Rationale:Ganglions are cell bodies of the dorsal neurons clustered in a knot-like structure. Fascicles are bundles of nerve fibers contained within a nerve. Plexuses are nerve networks outside the spinal cord.

Page 32: Chapter10 - Nervous Sytem

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Regions of the brainRegions of the brain

Cerebrum

Diencephalon

CerebellumMidbrain

Pons

Medulla oblongata

Brainstem

Page 33: Chapter10 - Nervous Sytem

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Meninges of the brainMeninges of the brain

Dural sinus

Subdural space

Subarachnoid space

Falx cerebri

Dura mater

Arachnoid mater

Pia mater

Skull

Page 34: Chapter10 - Nervous Sytem

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VentriclesVentricles

Lateral ventricles

Third ventricle

Fourth ventricle

Page 35: Chapter10 - Nervous Sytem

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Cerebrospinal fluidCerebrospinal fluid

<insert link to animation of “Formation and flow of CSF”>

Page 36: Chapter10 - Nervous Sytem

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Which statement about gray matter is true?

A.It is charged with thought, learning, and reasoning.B.It forms the interior of the brain.C.It consists of myelinated fibers.D.It secretes cerebrospinal fluid.

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Correct answer: A

Rationale:Gray matter covers the surface of the brain, and it consists of unmyelinated fibers. The choroid plexus secretes cerebrospinal fluid.

Page 38: Chapter10 - Nervous Sytem

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BrainstemBrainstem

Midbrain

Pons

Medulla obtongata

Page 39: Chapter10 - Nervous Sytem

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CerebellumCerebellum

Cerebellum

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DiencephalonDiencephalon

Thalamus

Hypothalamus

Page 41: Chapter10 - Nervous Sytem

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Reticular activating systemReticular activating system

Page 42: Chapter10 - Nervous Sytem

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The cardiac and respiratory centers are found in the:

A.pons.B.cerebellum.C.diencephalon.D.medulla oblongata.

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Correct answer: D

Rationale:The pons conveys signals to and from other parts of the brain. The cerebellum monitors body movement. The diencephalon houses the thalamus and hypothalamus.

Page 44: Chapter10 - Nervous Sytem

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CerebrumCerebrum

Frontal lobeFrontal lobe

Temporal lobeTemporal lobe

Parietal lobeParietal lobe

Occipital lobeOccipital lobe

Insula

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Inside the cerebrumInside the cerebrum

White matter

Corpus callosum

Cerebral cortex

Basal nuclei

Spinal tracts

Page 46: Chapter10 - Nervous Sytem

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Limbic systemLimbic system The “emotional brain” HippocampusHippocampus: Converts short-term

memory into long-term memory AmygdalaAmygdala: Stores and can recall

emotion

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Sensory functions of theSensory functions of thecerebral cortexcerebral cortex

Postcentral gyrus

Somatic sensory association area

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Motor functions of theMotor functions of thecerebral cortexcerebral cortex

Precentral gyrus

Motor association area

Page 49: Chapter10 - Nervous Sytem

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LanguageLanguageSequence of events required to read aloudSequence of events required to read aloud

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Page 50: Chapter10 - Nervous Sytem

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The limbic system is charged with:

A.emotion and learning.B.identifying the location of pain.C.planning muscle movements to form words.D.determining muscle movements to perform a task.

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Correct answer: A

Rationale:The somatic sensory association area allows us to pinpoint the location of pain. Broca’s area plans muscle movements to form words. Neurons in the motor association area determine the movements required to perform a task.

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Special sensesSpecial sensesPrimary gustatory complex

Primary visual cortex

Visual association area

Olfactory association area

Auditory association area

Primary auditory complex

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SleepSleep Stage 1Stage 1: Drowsiness Stage 2Stage 2: Light sleep Stage 3Stage 3: Moderate to deep sleep Stage 4Stage 4: Slow-wave sleep REM sleepREM sleep: Dream sleep

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Cerebral lateralizationCerebral lateralization

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Cranial Cranial nervesnerves< View animation on "Cranial Nerves">

Page 56: Chapter10 - Nervous Sytem

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Autonomic nervous systemAutonomic nervous system Regulates activities that maintain

homeostasis Sends impulses to cardiac and

smooth muscle Also called visceral motor system

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Visceral reflexesVisceral reflexes

<View animation of “Visceral (somatic) reflex arc">

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Autonomic vs. somatic Autonomic vs. somatic pathwayspathways

Somatic pathwaySomatic pathway

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Autonomic vs. somatic Autonomic vs. somatic pathwayspathways

Autonomic pathwayAutonomic pathway

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Divisions of the autonomic Divisions of the autonomic nervous systemnervous system

SympatheticSympathetic: Prepares the body for activity

ParasympatheticParasympathetic: Calms body functions

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SympathetiSympathetic divisionc division<View animation of "Structure of the sympathetic division">

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Adrenal Adrenal glandsglands

Play a role in sympathetic nervous system

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ParasympathParasympathetic divisionetic division

<View animation of “Structure of the parasympathetic division”>

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SYMPATHETIC PARASYMPATHETIC Originates in thoracolumbar

region Originates in craniosacral

region Ganglia lie in chain alongside

spinal cord Ganglia lie in or near target

organs Has short preganglionic and

long postganglionic fiber Has long preganglionic and short postganglionic fiber

Employs mostly norepinephrine as a

neurotransmitter (occasionally uses acetylcholine)

Employs acetylcholine as a neurotransmitter

Produces widespread, generalized effects

Produces local effects

Page 65: Chapter10 - Nervous Sytem

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Which of the following is an action of the parasympathetic division of the autonomic nervous system?

A.Increase heart rate B.Constriction of bronchial tubesC.Stimulation of sweat glandsD.Inhibition of intestinal motility

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Correct answer: B

Rationale:The sympathetic division increases heart rate, stimulates sweat glands, and inhibits intestinal motility.

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NeurotransmittersNeurotransmitters

Cholinergic fibersCholinergic fibers

Preganglionic fibers of sympathetic and parasympathetic divisions

Postganglionic fibers of parasympathetic division

Secrete acetylcholineacetylcholine

Adrenergic fibersAdrenergic fibers

Include most postganglionic fibers of the sympathetic division

Secrete norepinephrinenorepinephrine

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Cholinergic receptorsCholinergic receptors

Nicotinic receptorsNicotinic receptors

Occur within the adrenal medulla and the neuromuscular junction

Produce an excited response

Muscarinic receptors Muscarinic receptors

Occur on glands, smooth muscle, and cardiac muscle cells of organs innervated by cholinergic fibers

Produce a variable response

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Adrenergic receptorsAdrenergic receptors Cells with alpha-adrenergic receptorsalpha-adrenergic receptors

are excitedexcited by norepinephrine (NE). Cells with beta-adrenergic receptors beta-adrenergic receptors

are inhibitedinhibited by NE. <View animation of "Receptors of the

sympathetic and parasympathetic divisions">

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The effect produced by a neurotransmitter is ultimately determined by:

A.the amount of neurotransmitter released.B.the type of neurotransmitter released.C.the type of receptor.D.the number of receptors.

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Correct answer: C

Rationale:The amount of neurotransmitter influences the strength (not type) of a response. Although the effect varies according to the type of neurotransmitter, the same neurotransmitter bound to a different receptor will have a different response. Therefore, it is the receptor that ultimately determines the response. The number of receptors influences the strength of the response.