The Nervous System. Copyright © 2010 Pearson Education, Inc. Central nervous system (CNS) Brain and spinal cord Integrative and control centers Peripheral.

The Nervous System

Copyright © 2010 Pearson Education, Inc.

Central nervous system (CNS)

Brain and spinal cordIntegrative and control centers

Peripheral nervous system (PNS)

Cranial nerves and spinal nervesCommunication lines between theCNS and the rest of the body

Parasympatheticdivision

Conserves energyPromotes house-keeping functionsduring rest

Motor (efferent) division

Motor nerve fibersConducts impulses from the CNSto effectors (muscles and glands)

Sensory (afferent) divisionSomatic and visceral sensorynerve fibersConducts impulses fromreceptors to the CNS

Somatic nervousSystem (SNS)

Somatic motor(voluntary)Conducts impulsesfrom the CNS toskeletal muscles

Sympathetic divisionMobilizes bodysystems during activity; “fight or flight”

Autonomic nervoussystem (ANS)

Visceral motor(involuntary)Conducts impulsesfrom the CNS tocardiac muscles,smooth muscles,and glands

StructureFunctionSensory (afferent)division of PNS Motor (efferent) division of PNS

Somatic sensoryfiber

Visceral sensory fiber

Motor fiber of somatic nervous system

Skin

StomachSkeletalmuscle

Heart

BladderParasympathetic motor fiber of ANS

Sympathetic motor fiber of ANS

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Capillary

Neuron

Astrocyte

Astrocytes

Microglia

Neuron

Microglialcell

Ependymal Cells

Brain orspinal cordtissue

Ependymalcells

Fluid-filled cavity

Oligodendrocytes

Nervefibers

Myelin sheath

Process ofoligodendrocyte

Satellite Cells and Schwann Cells

Schwann cells(forming myelin sheath)

Cell body of neuronSatellitecells

Nerve fiber

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Dendrites(receptive regions)

Cell body(biosynthetic centerand receptive region)

Nucleolus

Nucleus

Nissl bodies

Axon(impulse generatingand conducting region)

Axon hillock

NeurilemmaTerminalbranches

Node of Ranvier

Impulsedirection

Schwann cell(one inter-node)

Axonterminals(secretoryregion)

Copyright © 2010 Pearson Education, Inc. Table 11.1 (1 of 3)

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Actionpotential

1 2 3

4

Resting state Depolarization Repolarization

Hyperpolarization

The big picture

1 1

2

3

4

Time (ms)

Threshold

Mem

bra

ne p

ote

nti

al (m

V)

Refractory Period

Generation of an Action Potential

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Copyright © 2010 Pearson Education, Inc.

Neural Pools

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Neural Pools

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Neural Pools

The Brain and Spinal Cord

Skin of scalp

Periosteum

Falx cerebri(in longitudinalfissure only)

Blood vessel

Arachnoid villusPia Mater

Arachnoid Mater

Dura Mater MeningealPeriostealBone of skull

Superiorsagittal sinus

Subduralspace

Subarachnoidspace

Meninges

Cervicalenlargement

Dura andarachnoidmater

Lumbar enlargement

Conus medullaris

Cauda equina

Filumterminale

Cervicalspinal nerves

Lumbarspinal nerves

Sacralspinal nerves

Thoracicspinal nerves

The spinal cord and its nerve roots, with the bony vertebral arches removed. The dura mater and arachnoid mater are cut open and reflected laterally.

Spinal Cord

Cerebellum

Diencephalon

Cerebralhemisphere

Brain stem• Midbrain• Pons• Medullaoblongata

The Major Regions of the Brain

Anterior horn

Interventricularforamen

Inferiorhorn

Lateralaperture

Left lateral view

Lateral ventricle

Septum pellucidum

Third ventricle

Cerebral aqueduct

Anterior view

Fourth ventricleCentral canal

Inferior horn

Posteriorhorn

MedianapertureLateralaperture

Ventricles of the Brain

Postcentralgyrus

Centralsulcus

Precentral gyrus

Frontal lobe Parietal lobeParieto-occipital sulcus(on medial surfaceof hemisphere)Lateral sulcus

Transverse cerebral fissure

Occipital lobeTemporal lobe

CerebellumPons

Medulla oblongataSpinal cord

Cortex (gray matter)

Fissure(a deepsulcus)

Gyrus

SulcusWhite matter

Cerebral Hemispheres

CentralsulcusFrontal lobe

Temporal lobe(pulled down)

Gyri of insula

Cerebral Hemispheres

Parietallobe

Frontal lobe

Right cerebralhemisphere

Occipitallobe

Left cerebralhemisphere

Cerebral veinsand arteriescovered byarachnoidmater

Longitudinalfissure

Posterior

Anterior

Cerebral Hemispheres

Gustatory cortex(in insula)

Primary motor cortex

Premotor cortex

Frontal eye field

Working memoryfor spatial tasksExecutive area fortask managementWorking memory forobject-recall tasks

Broca’s area(outlined by dashes)

Solving complex,multitask problems

(a) Lateral view, left cerebral hemisphere

Motor areas

Prefrontal cortex

Sensory areas and relatedassociation areas

Central sulcus

Primary somatosensorycortexSomatosensoryassociation cortex

Somaticsensation

Taste

Wernicke’s area(outlined by dashes)

Primary visualcortexVisualassociation area

Vision

Auditoryassociation areaPrimaryauditory cortex

Hearing

Primary motor cortex Motor association cortex Primary sensory cortex

Sensory association cortex Multimodal association cortex

Functional Areas of the Cerebral Cortex

Frontal eye field

Prefrontalcortex

Processes emotionsrelated to personaland social interactions

(b) Parasagittal view, right hemisphere

Olfactory bulbOrbitofrontalcortex

Olfactory tractFornix

Temporal lobe

Corpuscallosum

Premotor cortexPrimarymotor cortex

Cingulategyrus Central sulcus

Primary somatosensorycortex

Parietal lobe

Parieto-occipitalsulcus

Somatosensoryassociation cortex

OccipitallobeVisualassociationarea

Calcarine sulcusParahippocampalgyrus

UncusPrimaryolfactory cortex

Primaryvisual cortex

Primary motor cortex Motor association cortex Primary sensory cortex

Sensory association cortex Multimodal association cortex

Hemispheric Lateralization

Figure 12.12

Corpus callosum

Choroid plexusThalamus(encloses third ventricle)

Pineal gland(part of epithalamus)

Posterior commissure

CorporaquadrigeminaCerebralaqueductArbor vitae (ofcerebellum)Fourth ventricleChoroid plexusCerebellum

Septum pellucidum

Interthalamicadhesion(intermediatemass of thalamus)Interven-tricularforamenAnteriorcommissure

Hypothalamus

Optic chiasma

Pituitary gland

Cerebral hemisphere

Mammillary bodyPonsMedulla oblongata

Spinal cord

Mid-brain

Fornix

Diencephalon

Frontal lobeOlfactory bulb(synapse point ofcranial nerve I)Optic chiasmaOptic nerve (II)Optic tractMammillary body

Pons

MedullaoblongataCerebellum

Temporal lobe

Spinal cord

Midbrain

Brain Stem

Optic chiasmaView (a)

Optic nerve (II)

Mammillary body

Oculomotor nerve (III)

Crus cerebri ofcerebral peduncles (midbrain)

Trigeminal nerve (V)

Abducens nerve (VI)Facial nerve (VII)

Vagus nerve (X)

Accessory nerve (XI)

Hypoglossal nerve (XII)

Ventral root of firstcervical nerve

Trochlear nerve (IV)

PonsMiddle cerebellarpeduncle

Pyramid

Decussation of pyramids

Ventral view

Spinal cord

Vestibulocochlearnerve (VIII)

Glossopharyngeal nerve (IX)

Diencephalon• Thalamus• Hypothalamus

Diencephalon

Brainstem

Thalamus

Hypothalamus

Midbrain

Pons

Medullaoblongata

Brain Stem

View (c)

Diencephalon

Brainstem

Thalamus

Hypothalamus

Midbrain

Pons

Medullaoblongata

Pineal gland

Diencephalon

Anterior wall offourth ventricle

Dorsal view

Thalamus

Dorsal root offirst cervical nerve

Midbrain• Superior

colliculus• Inferior

colliculus• Trochlear nerve (IV)• Superior cerebellar peduncle

Corporaquadrigeminaof tectum

Medulla oblongata• Inferior cerebellar peduncle• Facial nerve (VII)• Vestibulocochlear nerve (VIII)• Glossopharyngeal nerve (IX)• Vagus nerve (X)• Accessory nerve (XI)

Pons• Middle cerebellar peduncle

Dorsal median sulcus

Choroid plexus(fourth ventricle)

Brain Stem