Chapter 10 Medical Chapter 10 Medical Terminology Terminology

andandChapters 8 – 9 Body Chapters 8 – 9 Body

Structures:Structures:

THE NERVOUS SYSTEMTHE NERVOUS SYSTEM

FUNCTIONS FUNCTIONS OFOF THE NERVOUS THE NERVOUS SYSTEMSYSTEM

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

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

STRUCTURES OF THE STRUCTURES OF THE NERVOUS SYSTEMNERVOUS SYSTEM

BRAINBRAIN SPINAL CORDSPINAL CORD NERVESNERVES SENSORY ORGANSSENSORY ORGANS

CNS (central)CNS (central)

PNS (peripheral)PNS (peripheral) 12 pairs cranial nerves12 pairs cranial nerves 31 pairs of spinal 31 pairs of spinal

nervesnerves ANS (autonomic)ANS (autonomic)

Peripheral nerves Peripheral nerves Ganglia on either side Ganglia on either side

of the spinal cordof the spinal cord

NERVES – NERVES – one or bundles of neuron cells one or bundles of neuron cells (carrying impulses) connecting brain and spinal (carrying impulses) connecting brain and spinal

cord with bodycord with body TractTract: bundle or group of nerve fibers : bundle or group of nerve fibers

located within the brainlocated within the brainAscending:Ascending: carry impulses carry impulses towardtoward brain brainDescending:Descending: carry carry awayaway from brain from brain

GanglionGanglion: knotlike mass or group of nerve : knotlike mass or group of nerve cells located outside the CNScells located outside the CNS

PlexusPlexus: network of intersecting nerves and : network of intersecting nerves and blood or lymphatic vesselsblood or lymphatic vessels

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

Receptors:Receptors: sites in sensory organs that receive sites in sensory organs that receive external stimulationexternal stimulationSend stimulus through the sensory neurons to Send stimulus through the sensory neurons to

the brain for interpretationthe brain for interpretationStimulus:Stimulus: excites or activated nerve causing excites or activated nerve causing

an impulsean impulse Impulse:Impulse: wave of excitation transmitted wave of excitation transmitted

through nerve fibers and neuronsthrough nerve fibers and neurons

REFLEXESREFLEXES

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

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

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

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

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

emerge from skin, emerge from skin, carry impulses toward carry impulses toward brainbrain

ConnectingConnecting:: carry carry impulses from one impulses from one neuron to anotherneuron to another

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

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NEURON PARTSNEURON PARTS Each neuron contains a cell Each neuron contains a cell

body, several dendrites, a body, several dendrites, a single axon, and terminal end single axon, and terminal end fibersfibers DendritesDendrites: receive impulses and : receive impulses and

conduct them to the cell bodyconduct them to the cell body AxonAxon: extends away from the : extends away from the

cell body, conducts impulses cell body, conducts impulses away from the nerve cellaway from the nerve cell

Some but not all axons Some but not all axons protected by myelinprotected by myelin

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

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

dendrites

axonterminal endfibers

Synaptic pathway

NEUROTRANSMITTERSNEUROTRANSMITTERS

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

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MYELIN SHEATHMYELIN SHEATH PROTECTIVE PROTECTIVE

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

BrainBrain White color of White color of

myelinated nerve fibersmyelinated nerve fibers

Most Peripheral Most Peripheral NervesNerves

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

nucleus

Cell body

dendrite

axonMyelin sheath

Nodes of Ranvier

THE CENTRAL THE CENTRAL NERVOUS NERVOUS SYSTEMSYSTEM

MeningesMeninges Dura MaterDura Mater Arachnoid MembraneArachnoid Membrane Pia MaterPia Mater

Cerebrospinal FluidCerebrospinal Fluid The CerebrumThe Cerebrum

Cerebral HemispheresCerebral Hemispheres LobesLobes VentriclesVentricles

The ThalamusThe Thalamus The HypothalamusThe Hypothalamus

The CerebellumThe Cerebellum The BrainstemThe Brainstem

The MidbrainThe Midbrain The PonsThe Pons The Medulla OblongataThe Medulla Oblongata

The Spinal CordThe Spinal Cord

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

spinal cordspinal cord Dura MaterDura Mater – outermost membrane – outermost membrane Arachnoid MembraneArachnoid Membrane – second layer, loosely attached – second layer, loosely attached

to allow flow of fluid between layersto allow flow of fluid between layers Pia MaterPia Mater – third layer, located closest to brain and – third layer, located closest to brain and

spinal cord, rich in supply of blood vesselsspinal cord, rich in supply of blood vesselsSubarachnoid space: below arachnoid membrane, Subarachnoid space: below arachnoid membrane,

above pia mater – contains cerebrospinal fluidabove pia mater – contains cerebrospinal fluidEpidural space: above the dura mater – within Epidural space: above the dura mater – within

surrounding bone walls – cushions Dura Matersurrounding bone walls – cushions Dura MaterSubdural space: below the dura membrane – above Subdural space: below the dura membrane – above

the arachnoid membranethe arachnoid membrane

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

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

memory, association, and discriminationmemory, association, and discrimination

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

CEREBRAL LOBESCEREBRAL LOBES FrontalFrontal – controls – controls

motor functionsmotor functions ParietalParietal – receives – receives

and interprets nerve and interprets nerve impulses from the impulses from the sensory receptorssensory receptors

OccipitalOccipital – controls – controls eyesighteyesight

Temporal LobeTemporal Lobe – – controls senses of controls senses of hearing and smellhearing and smell

THALAMUS – THALAMUS – produces sensations by produces sensations by relaying impulses to/from the cerebral cortex and relaying impulses to/from the cerebral cortex and

the sense organs of the bodythe sense organs of the body

HypothalamusHypothalamus: 7 regulatory functions: 7 regulatory functionsControls heart rate, blood pressure, Controls heart rate, blood pressure,

respiratory rate, and digestive tract activity by respiratory rate, and digestive tract activity by regulating autonomic nervous systemregulating autonomic nervous system

Regulates emotional responses and behaviorRegulates emotional responses and behaviorRegulates body temperatureRegulates body temperatureRegulates food intake by controlling hunger Regulates food intake by controlling hunger

sensationssensationsRegulates water balance and thirstRegulates water balance and thirstRegulates sleep-wake cyclesRegulates sleep-wake cyclesRegulates endocrine system activityRegulates endocrine system activity

CEREBELLUMCEREBELLUM

Second largest part of the brainSecond largest part of the brainReceives incoming messages regarding Receives incoming messages regarding

movement within joints, muscle tone, and movement within joints, muscle tone, and positions of the bodypositions of the bodyFrom here messages are distributed to From here messages are distributed to

corresponding parts of the brain that controls corresponding parts of the brain that controls skeletal musclesskeletal muscles

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

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

centerscenters

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 control the Nerve cells cross from one side of the brain to control the

opposite side of the body (injuries)opposite side of the body (injuries)

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

heart rate, and blood pressureheart rate, and blood pressure

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

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

Protected by CSF Protected by CSF and meningesand meninges

Grey Matter = internal Grey Matter = internal sectionsection

White Matter = outer White Matter = outer portion of the spinal portion of the spinal cordcord

www.bmb.psu.edu/.../bisci004a/ nerve/nerveb4.htm

THE PERIPHERAL NERVOUS THE PERIPHERAL NERVOUS SYSTEM - PNSSYSTEM - PNS

Consists of:Consists of:Cranial nerves: 12 pairs originating from Cranial nerves: 12 pairs originating from

under the brainunder the brainEach nerve of a pair serves half the bodyEach nerve of a pair serves half the bodyBoth nerves in a pair are identical in functionBoth nerves in a pair are identical in functionIdentified by Roman numerals names for the area Identified by Roman numerals names for the area

or function they serveor function they serveSpinal nerves: 31 pairsSpinal nerves: 31 pairs

Usually named for the artery they accompany or Usually named for the artery they accompany or the body part they innervatethe body part they innervate

Femoral nerve innervates muscles associated with the Femoral nerve innervates muscles associated with the femurfemur

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THE AUTONOMIC NERVOUS THE AUTONOMIC NERVOUS SYSTEM - ANSSYSTEM - ANS

Controls involuntary actions of the bodyControls involuntary actions of the body 2 divisions: function to maintain homeostasis2 divisions: function to maintain homeostasis

Sympathetic: prepares body for emergency and Sympathetic: prepares body for emergency and stressful situations stressful situations

Parasympathetic: returns body to normal after a Parasympathetic: returns body to normal after a stressful responsestressful response

MEDICAL SPECIALTIES MEDICAL SPECIALTIES RELATED TO THE NERVOUS RELATED TO THE NERVOUS

SYSTEMSYSTEMAnesthesiologistAnesthesiologistNeurologistNeurologistNeurosurgeonNeurosurgeonPsychiatristPsychiatristPsychologistPsychologist

PATHOLOGY OF THE PATHOLOGY OF THE NERVOUS SYSTEMNERVOUS SYSTEM

Head and MeningesHead and Meninges Cephalalgia: headacheCephalalgia: headache Migraine HeadacheMigraine Headache EncephaloceleEncephalocele Hydrocephalus: Hydrocephalus:

increase amount of CSFincrease amount of CSF Meningocele: protrusion Meningocele: protrusion

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

MeningitisMeningitis

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DISORDERS OF THE BRAINDISORDERS OF THE BRAIN

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

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

EncephalitisEncephalitisParkinson’s diseaseParkinson’s diseaseTetanusTetanus

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

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

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

Cranial HematomasCranial Hematomas: : collection of blood collection of blood trapped in the tissues of trapped in the tissues of the brainthe brain

ALTERED STATES OF ALTERED STATES OF CONSCIOUSNESSCONSCIOUSNESS

Conscious: alertConscious: alert Syncope (SIN-koh-pee): also known as fainting, is the Syncope (SIN-koh-pee): also known as fainting, is the

brief loss of consciousness caused by the decreased brief loss of consciousness caused by the decreased flow of blood to the brain.flow of blood to the brain.

Lethargy: lowered level of consciousness, listlessness, Lethargy: lowered level of consciousness, listlessness, drowsiness, and apathydrowsiness, and apathy

ComaComa Delirium: associated with high fever, sudden onset Delirium: associated with high fever, sudden onset

where patient is confused, disoriented, and unable to where patient is confused, disoriented, and unable to think clearlythink clearly

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

STROKES – (CVA)STROKES – (CVA) damage to the brain damage to the brain that occurs when blood flow is disrupted due to that occurs when blood flow is disrupted due to

vessel blockage or rupturevessel blockage or rupture Ischemic AttacksIschemic Attacks

TIA: temporary interruption in blood supply to TIA: temporary interruption in blood supply to brain, weakness, dizziness, or loss of balancebrain, weakness, dizziness, or loss of balance

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

Aphasia: inability to speak, write, or Aphasia: inability to speak, write, or comprehend written or spoken wordcomprehend written or spoken word

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

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SLEEP DISORDERSSLEEP DISORDERS

Insomnia: abnormal Insomnia: abnormal inability to sleepinability to sleep

Narcolepsy: recurrent Narcolepsy: recurrent uncontrollable uncontrollable seizures of seizures of drowsiness and sleepdrowsiness and sleep

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SPINAL CORDSPINAL CORD

Myelitis: inflammation of the spinal cordMyelitis: inflammation of the spinal cordMyelosis: tumor of spinal cordMyelosis: tumor of spinal cordMultiple sclerosisMultiple sclerosisPoliomyelitisPoliomyelitisPost polio syndromePost polio syndromeRadiculitis: pinched nerve, inflammation of Radiculitis: pinched nerve, inflammation of

root of spinal nerveroot of spinal nerveSpinal cord injuries Spinal cord injuries

CONVULSIONS AND SEIZURES – CONVULSIONS AND SEIZURES – sudden, violent, involuntary contraction of a group sudden, violent, involuntary contraction of a group

of muscles caused by a disturbance in brain of muscles caused by a disturbance in brain functionfunction

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

contraction resulting in rigidity and violent contraction resulting in rigidity and violent spasmsspasms

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

Localized seizure: partialLocalized seizure: partial

EPILEPSYEPILEPSY

Grand Mal Epilepsy: most severe formGrand Mal Epilepsy: most severe formPetit Mal Epilepsy: milder form, sudden, Petit Mal Epilepsy: milder form, sudden,

temporary loss of consciousness, lasting temporary loss of consciousness, lasting only a few seconds, they may not involve only a few seconds, they may not involve convulsive movements, and may not be convulsive movements, and may not be noticednoticed

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

MENTAL HEALTHMENTAL HEALTH Developmental DisordersDevelopmental Disorders Substance-Abuse DisordersSubstance-Abuse Disorders Schizophrenia and Other Psychotic DisordersSchizophrenia and Other Psychotic Disorders Mood DisordersMood Disorders Panic DisordersPanic Disorders Anxiety DisordersAnxiety Disorders PhobiasPhobias Somatoform DisordersSomatoform Disorders Impulse-Control DisordersImpulse-Control Disorders Personality DisordersPersonality Disorders

DIAGNOSTIC PROCEDURES OF DIAGNOSTIC PROCEDURES OF THE NERVOUS SYSTEMTHE NERVOUS SYSTEM

CT – CAT ScanCT – CAT ScanEchoencephalographyEchoencephalographyElectroencephalographyElectroencephalographyEncephalographyEncephalographyMyelography: radiographic study of spinal Myelography: radiographic study of spinal

cordcordLOC: level of consciousnessLOC: level of consciousness

Echoencephalography

Electricalencephalography

myelography

Ct scan

TREATMENT PROCEDURES OF TREATMENT PROCEDURES OF THE NERVOUS SYSTEMTHE NERVOUS SYSTEM

Medications to Treat Mental DisordersMedications to Treat Mental DisordersPain ControlPain ControlSedative and Hypnotic MedicationsSedative and Hypnotic MedicationsAnesthesiaAnesthesiaBrain and HeadBrain and HeadNervesNerves