Chapter 10 Chapter 10 Medical Medical

Terminology Terminology andand

Chapters 8 – 9 Chapters 8 – 9 Body Structures:Body Structures:

THE NERVOUS THE NERVOUS SYSTEMSYSTEM

FUNCTIONS FUNCTIONS OFOF THE THE NERVOUS SYSTEMNERVOUS SYSTEM

Coordinates and Coordinates and controls all bodily controls all bodily activities with the activities with the brain at the center brain at the center of controlof control

When the brain When the brain ceases function, ceases function, the body diesthe body dies

STRUCTURES OF THE STRUCTURES OF THE NERVOUS SYSTEMNERVOUS SYSTEM

BRAINBRAIN SPINAL CORDSPINAL CORD NERVESNERVES SENSORY SENSORY

ORGANSORGANS

CNS (central)CNS (central)

PNS PNS (peripheral)(peripheral) 12 pairs cranial 12 pairs cranial

nervesnerves 31 pairs of 31 pairs of

spinal nervesspinal nerves ANS ANS

(autonomic)(autonomic) Peripheral Peripheral

nerves nerves Ganglia on Ganglia on

either side of either side of the spinal cordthe spinal cord

NERVES – NERVES – one or bundles of one or bundles of neuron cells (carrying impulses) neuron cells (carrying impulses)

connecting brain and spinal cord with connecting brain and spinal cord with

bodybody TractTract: bundle or group of nerve : bundle or group of nerve

fibers located within the brainfibers located within the brainAscending:Ascending: carry impulses carry impulses towardtoward

brainbrainDescending:Descending: carry impulses carry impulses awayaway

from brainfrom brain GanglionGanglion: knotlike mass or : knotlike mass or

group of nerve cells located group of nerve cells located outside the CNSoutside the CNS

PlexusPlexus: network of intersecting : network of intersecting nerves and blood or lymphatic nerves and blood or lymphatic vesselsvessels

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Innervation:Innervation: supply of nerves to supply of nerves to body part, stimulation of a body body part, stimulation of a body part through action of nervespart through action of nerves

Receptors:Receptors: sites in sensory organs sites in sensory organs that receive external stimulationthat receive external stimulationSend stimulus through the Send stimulus through the

sensory neurons to the brain for sensory neurons to the brain for interpretationinterpretation

Stimulus:Stimulus: excites or activates excites or activates nerve causing an impulsenerve causing an impulse

Impulse:Impulse: wave of excitation wave of excitation transmitted through nerve fibers transmitted through nerve fibers and neuronsand neurons

REFLEXESREFLEXES

Automatic, involuntary Automatic, involuntary response to change, response to change, inside/outside bodyinside/outside body

Maintenance of heart rate, Maintenance of heart rate, breathing rate, and blood breathing rate, and blood pressure = reflex actionspressure = reflex actions

Coughing, sneezing, and Coughing, sneezing, and reactions to painful stimuli are reactions to painful stimuli are also reflex actionsalso reflex actions

THE NEURONS – THE NEURONS – THE THE BASIC CELL OF THE BASIC CELL OF THE NERVOUS SYSTEMNERVOUS SYSTEM

3 types 3 types described described according to according to function (ACE)function (ACE) AfferentAfferent::

sensory, sensory, emerge from emerge from skin, carry skin, carry impulses impulses toward braintoward brain

ConnectingConnecting:: carry impulses carry impulses from one from one neuron to neuron to anotheranother

EfferentEfferent:: carry carry impulses away impulses away from brain from brain toward muscles toward muscles and glandsand glands

NEURON NEURON PARTSPARTS Each neuron contains Each neuron contains

a cell body, several a cell body, several dendrites, a single dendrites, a single axon, and terminal axon, and terminal end fibersend fibers DendritesDendrites: receive : receive

impulses and conduct impulses and conduct them to the cell bodythem to the cell body

AxonAxon: extends away : extends away from the cell body, from the cell body, conducts impulses conducts impulses away from the nerve away from the nerve cellcell

Some but not all Some but not all axons protected by axons protected by myelinmyelin

Terminal end fibers:Terminal end fibers: lead the nervous lead the nervous impulse away from the impulse away from the axon and toward the axon and toward the synapsesynapse

Synapse: space between two neurons or between a neuron and receptor organ

dendrites

axon

terminal endfibers

Synaptic pathway

NEUROTRANSMITTERSNEUROTRANSMITTERS

Chemical Chemical messengers that messengers that transmit transmit messages messages between nerve between nerve cells allowing a cells allowing a nerve impulse to nerve impulse to jump across the jump across the synapse from one synapse from one neuron to anotherneuron to another

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MYELIN SHEATHMYELIN SHEATH PROTECTIVE PROTECTIVE

COVERING COVERING OVER SOME OVER SOME NERVE CELLSNERVE CELLS Spinal CordSpinal Cord White MatterWhite Matter of of

the Brainthe Brain White color of White color of

myelinated myelinated nerve fibersnerve fibers

Most Most Peripheral Peripheral NervesNerves

Gray Matter: non-myelinated nerves of the brain and spinal cord

nucleus

Cell body

dendrite

axon

Myelin sheath

Nodes of Ranvier

THE THE CENTRAL CENTRAL NERVOUS NERVOUS SYSTEMSYSTEM

MeningesMeninges Dura MaterDura Mater Arachnoid Arachnoid

MembraneMembrane Pia MaterPia Mater

Cerebrospinal FluidCerebrospinal Fluid The CerebrumThe Cerebrum

Cerebral Cerebral HemispheresHemispheres

LobesLobes VentriclesVentricles

The ThalamusThe Thalamus The The

HypothalamusHypothalamus The CerebellumThe Cerebellum The BrainstemThe Brainstem

The MidbrainThe Midbrain The PonsThe Pons The Medulla The Medulla

OblongataOblongata The Spinal CordThe Spinal Cord

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MENINGESMENINGES 3 Layers of connective tissue that enclose 3 Layers of connective tissue that enclose

brain and spinal cordbrain and spinal cord Dura MaterDura Mater – outermost membrane – outermost membrane Arachnoid MembraneArachnoid Membrane – second layer, – second layer,

loosely attached to allow flow of fluid loosely attached to allow flow of fluid between layersbetween layers

Pia MaterPia Mater – third layer, located closest – third layer, located closest to brain and spinal cord, rich in supply to brain and spinal cord, rich in supply of blood vesselsof blood vesselsSubarachnoid space: below Subarachnoid space: below

arachnoid membrane, above pia arachnoid membrane, above pia mater – contains cerebrospinal fluidmater – contains cerebrospinal fluid

Epidural space: above the duramater Epidural space: above the duramater – within surrounding bone walls – – within surrounding bone walls – cushions Dura Matercushions Dura Mater

Subdural space: below the dura Subdural space: below the dura membrane – above the arachnoid membrane – above the arachnoid membranemembrane

CEREBRUM – CEREBRUM – cerebral: cerebral: pertaining to cerebrum or brainpertaining to cerebrum or brain

Largest/uppermost portion of Largest/uppermost portion of the brainthe brainResponsible for all thought, Responsible for all thought,

judgment, memory, association, judgment, memory, association, and discriminationand discrimination

Cerebral Cortex: made up of Cerebral Cortex: made up of gray matter, the outermost gray matter, the outermost layer of the cerebrumlayer of the cerebrum

CEREBRAL LOBESCEREBRAL LOBES

FrontalFrontal – controls motor functions – controls motor functions

ParietalParietal – receives and interprets – receives and interprets

nerve impulses from the sensory nerve impulses from the sensory receptorsreceptors

OccipitalOccipital – controls eyesight – controls eyesight

Temporal LobeTemporal Lobe – –

controls senses of hearing and smellcontrols senses of hearing and smell

THALAMUS – THALAMUS – produces produces sensations by relaying impulses sensations by relaying impulses

to/from the cerebral cortex and the to/from the cerebral cortex and the sense organs of the bodysense organs of the body

HypothalamusHypothalamus: 7 regulatory : 7 regulatory functionsfunctionsControls heart rate, blood Controls heart rate, blood

pressure, respiratory rate, and pressure, respiratory rate, and digestive tract activity by digestive tract activity by regulating autonomic nervous regulating autonomic nervous systemsystem

Regulates emotional responses Regulates emotional responses and behaviorand behavior

Regulates body temperatureRegulates body temperatureRegulates food intake by Regulates food intake by

controlling hunger sensationscontrolling hunger sensationsRegulates water balance and Regulates water balance and

thirstthirstRegulates sleep-wake cyclesRegulates sleep-wake cyclesRegulates endocrine system Regulates endocrine system

activityactivity

CEREBELLUMCEREBELLUM

Second largest part of the Second largest part of the brainbrain

Receives incoming messages Receives incoming messages regarding movement within regarding movement within joints, muscle tone, and joints, muscle tone, and positions of the bodypositions of the bodyFrom here messages are From here messages are

distributed to corresponding distributed to corresponding parts of the brain that control parts of the brain that control skeletal musclesskeletal muscles

THE BRAINSTEM – THE BRAINSTEM – connects connects cerebral hemispheres with the spinal cordcerebral hemispheres with the spinal cord

The MidbrainThe Midbrain – extends from the lower surface of – extends from the lower surface of the cerebrum to the pons –the cerebrum to the pons – provides conduction pathways to and from provides conduction pathways to and from

higher and lower centershigher and lower centers

The PonsThe Pons – at the base of the brain – at the base of the brain Nerve cells cross from one side of the brain to Nerve cells cross from one side of the brain to

control the oppositie side of the body (injuries)control the oppositie side of the body (injuries)

The Medulla OblongataThe Medulla Oblongata – located at the lowest – located at the lowest part of the brainstempart of the brainstem Controls basic life functions including the Controls basic life functions including the

muscles of respiration, heart rate, and blood muscles of respiration, heart rate, and blood pressurepressure

THE SPINAL CORD – THE SPINAL CORD – pathway for impulses going to and from the pathway for impulses going to and from the

brainbrain

Contains all the Contains all the nerves that nerves that affect the limbs affect the limbs and lower part and lower part of the bodyof the body

Protected by Protected by Cerebral Spinal Cerebral Spinal Fluid and Fluid and meningesmeninges

Grey Matter = Grey Matter = internal sectioninternal section

White Matter = White Matter = outer portion of outer portion of the spinal cordthe spinal cord www.bmb.psu.edu/.../bisci004a/ nerve/nerveb4.htm

THE PERIPHERAL THE PERIPHERAL NERVOUS SYSTEM - NERVOUS SYSTEM -

PNSPNSConsists of:Consists of:

Cranial nerves: 12 pairs Cranial nerves: 12 pairs originating from under the brainoriginating from under the brainEach nerve of a pair serves half the Each nerve of a pair serves half the

bodybodyBoth nerves in a pair are identical in Both nerves in a pair are identical in

functionfunctionIdentified by Roman numerals Identified by Roman numerals

named for the area or function they named for the area or function they serveserve

Spinal nerves: 31 pairsSpinal nerves: 31 pairsUsually named for the artery they Usually named for the artery they

accompany or the body part they accompany or the body part they innervateinnervate

Femoral nerve innervates muscles Femoral nerve innervates muscles associated with the femurassociated with the femur

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THE AUTONOMIC THE AUTONOMIC NERVOUS SYSTEM - NERVOUS SYSTEM -

ANSANS

Controls involuntary actions of the bodyControls involuntary actions of the body 2 divisions: function to maintain 2 divisions: function to maintain

homeostasishomeostasis Sympathetic: prepares body for Sympathetic: prepares body for

emergency and stressful situations emergency and stressful situations Parasympathetic: returns body to Parasympathetic: returns body to

normal after a stressful responsenormal after a stressful response

MEDICAL SPECIALTIES MEDICAL SPECIALTIES RELATED TO THE RELATED TO THE

NERVOUS SYSTEMNERVOUS SYSTEM

AnesthesiologistAnesthesiologistNeurologistNeurologistNeurosurgeonNeurosurgeonPsychiatristPsychiatristPsychologistPsychologist

PATHOLOGY OF PATHOLOGY OF THE NERVOUS THE NERVOUS

SYSTEMSYSTEM Head and Head and

MeningesMeninges Cephalalgia: Cephalalgia:

headacheheadache Migraine Migraine

HeadacheHeadache EncephaloceleEncephalocele Hydrocephalus: Hydrocephalus:

increased increased amount of CSFamount of CSF

Meningocele: Meningocele: protrusion of protrusion of membranes membranes through a defect through a defect in the skull or in the skull or spinal columnspinal column

MeningitisMeningitis

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DISORDERS OF THE BRAINDISORDERS OF THE BRAIN

Alzheimer’s disease: Alzheimer’s disease: associated with degenerative associated with degenerative changes in the brain structureschanges in the brain structures

Cognition: mental activities Cognition: mental activities associated with thinking, associated with thinking, learning, and memorylearning, and memory

EncephalitisEncephalitisParkinson’s diseaseParkinson’s diseaseTetanusTetanus

BRAIN BRAIN INJURIESINJURIES

Amnesia:Amnesia: disturbance in the disturbance in the memory marked by memory marked by total or partial total or partial inability to recall past inability to recall past experiences – cause experiences – cause BI, illness, or BI, illness, or psychological psychological disturbancesdisturbances

Concussion:Concussion: violent violent shaking up or jarring shaking up or jarring of the brainof the brain

Cerebral Contusion:Cerebral Contusion: bruising of brain bruising of brain tissue as result of BItissue as result of BI

Cranial HepatomasCranial Hepatomas: : collection of blood collection of blood trapped in the trapped in the tissues of the braintissues of the brain

ALTERED STATES OF ALTERED STATES OF CONSCIOUSNESSCONSCIOUSNESS

Conscious: alertConscious: alert Syncope: faintingSyncope: fainting Lethargy: lowered level of Lethargy: lowered level of

consciousness, listlessness, consciousness, listlessness, drowsiness, and apathydrowsiness, and apathy

Coma : loss of consciousnessComa : loss of consciousness Delirium: associated with high Delirium: associated with high

fever, sudden onset where patient fever, sudden onset where patient is confused, disoriented, and is confused, disoriented, and unable to think clearlyunable to think clearly

Dementia: slow, progressive Dementia: slow, progressive decline in mental abilities including decline in mental abilities including memory, thinking, judgment, and memory, thinking, judgment, and the ability to pay attentionthe ability to pay attention

STROKES – (CVA)STROKES – (CVA) damage damage to the brain that occurs when blood to the brain that occurs when blood

flow is disrupted due to vessel flow is disrupted due to vessel blockage or ruptureblockage or rupture

Ischemic AttacksIschemic AttacksTIA: temporary interruption in TIA: temporary interruption in

blood supply to brain: weakness, blood supply to brain: weakness, dizziness, or loss of balancedizziness, or loss of balance

Ischemic stroke: blood flow is Ischemic stroke: blood flow is blocked, affecting the cerebrum blocked, affecting the cerebrum and damaging the controls of and damaging the controls of movement, language, and movement, language, and sensessenses

Aphasia: inability to speak, write, Aphasia: inability to speak, write, or comprehend written or spoken or comprehend written or spoken wordword

Hemorrhagic Stroke – bleed – Hemorrhagic Stroke – bleed – leak or rupture of blood vessel leak or rupture of blood vessel in brainin brain

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SLEEP DISORDERSSLEEP DISORDERS Insomnia: Insomnia:

abnormal abnormal inability to inability to sleepsleep

Narcolepsy: Narcolepsy: recurrent recurrent uncontrollable uncontrollable seizures of seizures of drowsiness drowsiness

and sleepand sleep

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SPINAL CORDSPINAL CORD

Myelitis: inflammation of the Myelitis: inflammation of the spinal cordspinal cord

Myelosis: tumor of spinal cordMyelosis: tumor of spinal cordMultiple sclerosisMultiple sclerosisPoliomyelitisPoliomyelitisPost polio syndromePost polio syndromeRadiculitis: pinched nerve, Radiculitis: pinched nerve,

inflammation of root of spinal inflammation of root of spinal nervenerve

Spinal cord injuries Spinal cord injuries

CONVULSIONS AND CONVULSIONS AND SEIZURES – SEIZURES – sudden, violent, sudden, violent, involuntary contraction of a group of involuntary contraction of a group of muscles caused by a disturbance in muscles caused by a disturbance in

brain functionbrain function

Generalized tonic-clonic seizure: Generalized tonic-clonic seizure: Tonic convulsion: continuous Tonic convulsion: continuous

muscular contraction resulting in muscular contraction resulting in rigidity and violent spasmsrigidity and violent spasms

Clonic convulsion: alternate Clonic convulsion: alternate contraction and relaxation of contraction and relaxation of muscles resulting in jerking muscles resulting in jerking movements of the face, trunk, or movements of the face, trunk, or extremitiesextremities

Localized seizure: partialLocalized seizure: partial

EPILEPSYEPILEPSY

Grand Mal Epilepsy: most Grand Mal Epilepsy: most severe formsevere form

Petit Mal Epilepsy: milder form, Petit Mal Epilepsy: milder form, sudden, temporary loss of sudden, temporary loss of consciousness, lasting only a consciousness, lasting only a few seconds, they may not few seconds, they may not involve convulsive movements, involve convulsive movements, and may not be noticedand may not be noticed

Epileptic aura: experienced just Epileptic aura: experienced just before seizure, light or smellbefore seizure, light or smell

MENTAL HEALTHMENTAL HEALTH

Developmental DisordersDevelopmental Disorders Substance-Abuse DisordersSubstance-Abuse Disorders Schizophrenia and Other Psychotic Schizophrenia and Other Psychotic

DisordersDisorders Mood DisordersMood Disorders Panic DisordersPanic Disorders Anxiety DisordersAnxiety Disorders PhobiasPhobias Somatoform DisordersSomatoform Disorders Impulse-Control DisordersImpulse-Control Disorders Personality DisordersPersonality Disorders

DIAGNOSTIC DIAGNOSTIC PROCEDURES OF THE PROCEDURES OF THE

NERVOUS SYSTEMNERVOUS SYSTEMCT – CAT ScanCT – CAT ScanEchoencephalographyEchoencephalographyElectroencephalographyElectroencephalographyEncephalographyEncephalographyMyelography: radiographic Myelography: radiographic

study of spinal cordstudy of spinal cordLOC: level of consciousnessLOC: level of consciousness

Echoencephalography

Electricalencephalography

myelography

Ct scan

TREATMENT TREATMENT PROCEDURES OF THE PROCEDURES OF THE

NERVOUS SYSTEMNERVOUS SYSTEMMedications to Treat Mental Medications to Treat Mental

DisordersDisordersPain ControlPain ControlSedative and Hypnotic Sedative and Hypnotic

MedicationsMedicationsAnesthesiaAnesthesia