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11/14/2017

Medical Terminology A Living Language

CHAPTER

Medical Terminology: A Living Language, Sixth Edition Bonnie F. Fremgen | Suzanne S. Frucht

SIXTH EDITION

Nervous System

Nervous System at a Glance

• Functions

 Coordinates and controls body function

 Receives sensory input

 Makes decisions

 Orders body responses

continued on next slide

Nervous System at a Glance

• Organs

 Brain

 Spinal cord

 Nerves

Nervous System Combining Forms

• alges/o – sense of pain

• astr/o – star

• centr/o – center

• cerebell/o – cerebellum

• cerebr/o – cerebrum

• clon/o – rapid contracting and relaxing

• concuss/o – to shake violently

• dur/o – dura mater continued on next slide

Nervous System Combining Forms

• encephal/o – brain

• esthes/o – sensation, feeling

• gli/o – glue

• medull/o – medulla

• mening/o – meninges

• meningi/o – meninges

• ment/o – mind

• myel/o – spinal cord continued on next slide

Nervous System Combining Forms

• neur/o – nerve

• peripher/o – away from center

• poli/o – gray matter

• pont/o – pons

• radicul/o – nerve root

• thalam/o – thalamus

• thec/o – sheath (meninges)

• tom/o – to cut continued on next slide

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Nervous System Combining Forms

• ton/o – tone

• ventricul/o – ventricle

Nervous System Suffixes

• –paresis weakness

• –phasia speech

• –taxia muscle coordination

Anatomy and Physiology of the Nervous System

• Coordinates all activity of body

 Receives information from both external

and internal sensory receptors

 Uses that information to adjust activity of muscles and glands to match needs of body

• Nervous system is divided into:

 Central nervous system (CNS)

 Peripheral nervous system (PNS) continued on next slide

Anatomy and Physiology of the Nervous System

• Central nervous system consists of:

 Brain

 Spinal cord

• Peripheral nervous system consists of:

 Cranial nerves

 Spinal nerves

Nervous Tissue

• Nervous system composed of two types of cells

 Neurons

 Neuroglial cells

• Neurons

 Individual nerve cells

 Capable of conducting electrical impulses

continued on next slide

Nervous Tissue

• Neurons have three basic parts

 Dendrites

• Highly branched projections that receive impulses

 Nerve cell body

• Contains nucleus and organelles

 Axon

• Conducts electrical impulse to destination

continued on next slide

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Nervous Tissue

• Synapse

 Point where axon of one neuron meets

dendrite of second neuron

• Synaptic cleft

 Gap between two neurons in a synapse

 Electrical impulse cannot cross

continued on next slide

Nervous Tissue

• Neurotransmitter

 Chemical released by axon

 Crosses gap to stimulate dendrite of second neuron

continued on next slide

Nervous Tissue

• Neuroglial cells

 Variety of cells found in nervous tissue

 Each has different support function for neurons

 Some neuroglial cells produce myelin, a fatty substance that acts as insulation for many axons

 Neuroglial cells do not conduct electrical

impulses

Central Nervous System

• Combination of the brain and spinal cord

• Function

 Receives impulses from all over body

 Processes this information

 Responds with action

• Bundles of nerve fibers interconnecting different parts of CNS are called tracts

continued on next slide

Central Nervous System

• Consists of both gray and white matter

• Gray matter

 Comprised of unsheathed or uncovered cell bodies and dendrites

• White matter

 Myelinated nerve fibers

Brain

• One of the largest organs in body

• Coordinates most body activities

• It is center for:

 Thoughts

 Memory

 Judgment

 Emotion

continued on next slide

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Brain

• Four sections

 Cerebrum

 Cerebellum

 Diencephalon

 Brain stem

Cerebrum

• Largest section

• Upper portion

• Processes

 Thoughts

 Judgment

 Memory

 Association skills

 Ability to discriminate between items

Figure 12.3 The regions of the brain.

Cerebrum

• Cerebral cortex

 Outer layer of cerebrum

 Composed of folds of gray matter

• Gyri

 Elevated portions of the cerebrum, or convolutions

• Sulci

 Fissures, or valleys, between gyri

continued on next slide

Cerebrum

• Subdivided into left and right halves called cerebral hemispheres

• Each hemisphere has four lobes

 Frontal lobe

 Parietal lobe

 Occipital lobe

 Temporal lobe

continued on next slide

Cerebrum

• Frontal lobe

 Most anterior lobe

 Controls motor function, personality, and speech

continued on next slide

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Cerebrum

• Parietal lobe

 Most superior portion

 Receives and interprets nerve impulses

 Interprets language

continued on next slide

Cerebrum

• Occipital lobe

 Most posterior

 Controls vision

• Temporal lobe

 Left and right lateral portion

 Controls hearing and smell

Figure 12.4 The functional regions of the cerebrum.

Diencephalon

• Located below cerebrum

• Contains two of most critical areas of brain

 Thalamus

 Hypothalamus

continued on next slide

Diencephalon

• Thalamus

 Center for relaying impulses from eyes,

ears, and skin to cerebrum

 Controls perception of pain

continued on next slide

Diencephalon

• Hypothalamus

 Controls body temperature, appetite,

sleep, sexual desire, and emotions

 Controls autonomic nervous system, cardiovascular system, gastrointestinal system, and release of hormones from pituitary gland

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Cerebellum

• Second largest portion of brain

• Located beneath posterior part of cerebrum

• Aids in:

 Coordinating voluntary body movements

 Maintaining balance and equilibrium

• Refines muscular movements initiated in cerebrum

Brain Stem

• Has three components

 Midbrain

 Pons

 Medulla oblongata

continued on next slide

Brain Stem

• Midbrain

 Acts as pathway for impulses between

brain and spinal cord

• Pons

 Means bridge

 Connects cerebellum to rest of brain

• Medulla oblongata

 Most inferior portion of brain

 Connects brain to spinal cord

Brain Ventricles

• Cavities containing cerebrospinal fluid (CSF)

 Watery, clear fluid

 Provides shock protection for CNS

• Locations

 One in each cerebral hemisphere

 One in thalamus

 One in front of cerebellum

Spinal Cord

• Extends from medulla oblongata to second lumbar vertebra

continued on next slide

Spinal Cord

• Within vertebral column

 33 vertebrae of back bone

 Line up to form continuous canal

 Called spinal cavity or vertebral

canal

continued on next slide

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Spinal Cord

• Protected by cerebrospinal fluid

 Flows through central canal down

through spinal cord

continued on next slide

Spinal Cord

• Outer portion of spinal cord is myelinated white matter

 Ascending tracts carry sensory

information up to brain

 Descending tracts carry motor commands down from brain to peripheral nerve

Figure 12.5A The levels of the spinal cord and spinal nerves.

continued on next slide

Meninges

• Protective membrane sac

• Encases entire CNS

• Consists of three layers

 Dura mater

 Arachnoid layer

 Pia mater

continued on next slide

Meninges

• Dura mater

 Means tough mother

 Outermost, tough, fibrous sac around CNS

• Subdural space

 Empty space between dura mater and arachnoid layer

continued on next slide

Meninges

• Arachnoid layer

 Means spider-like

 Thin, delicate layer attached to pia mater by web-like filaments

continued on next slide

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Meninges

• Subarachnoid space

 Between arachnoid layer and pia mater

 Contains cerebrospinal fluid

continued on next slide

Meninges

• Pia mater

 Means soft mother

 Innermost membrane layer

 Applied directly to surface of brain

Figure 12.6 The meninges. This figure illustrates the location and structure of each layer of the

meninges and their relationship to the skull and brain.

Peripheral Nervous System

• Consists of:

 12 pairs of cranial nerves

 31 pairs of spinal nerves

• Cranial nerves

 Arise from brain

• Spinal nerves

 Split off from spinal cord

 One pair (left and right) exit between each pair of vertebrae

continued on next slide

Peripheral Nervous System

• A nerve:

 Is a bundle of axon fibers located

outside CNS

 Carries messages between CNS and various parts of body

• Nerve root

 Point where nerve is attached to CNS

continued on next slide

Peripheral Nervous System

• Names of most nerves reflect:

 Organ the nerve serves

 Portion of body the nerve is traveling through

continued on next slide

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Table 12.1 Cranial Nerves

I Olfactory sense of smell

II Optic sense of sight

III Oculomotor controls eye muscles and pupil of eye

IV Trochlear controls oblique muscles of eye

V Trigeminal facial sensation and controls muscles for chewing

VI Abducens controls eyeball muscles to turn eye to side

continued on next slide

Table 12.1 Cranial Nerves

VII Facial

controls facial muscles for expression, salivation, and taste on two-thirds of tongue (anterior)

VIII Vestibulocochlear sense of equilibrium and hearing

IX Glossopharyngeal sensation from pharynx and taste on one-third of tongue

X Vagus supplies most organs in abdominal and thoracic cavities

continued on next slide

Table 12.1 Cranial Nerves

XI Accessory controls neck and shoulder muscles

XII Hypoglossal controls tongue muscles

Peripheral Nervous System

• Each nerve can carry information both to and from CNS

• But any individual neuron can carry information in only one direction

• Either an:

 Afferent neuron

 Efferent neuron

continued on next slide

Peripheral Nervous System

• Afferent neurons

 Also called sensory neurons

 Carry sensory information from sensory receptor to CNS

• Efferent neurons

 Also called motor neurons

 Carry activity instructions from CNS to muscles or glands

continued on next slide

Peripheral Nervous System

• Nerves of PNS are subdivided into two divisions

 Autonomic nervous system (ANS)

 Somatic nerves

• Each division serves different area of body

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Figure 12.8 A reflex arc showing afferent and efferent neurons.

Autonomic Nervous System (ANS)

• Control of involuntary or unconscious bodily functions

• It may increase or decrease the activity of:

 Smooth muscle found in viscera and blood vessels

 Cardiac muscle of heart

 Glands

continued on next slide

Autonomic Nervous System (ANS)

• ANS divided into 2 branches:

 Sympathetic branch

 Parasympathetic branch

continued on next slide

Autonomic Nervous System (ANS)

• Sympathetic branch

 Stimulates body in times of stress and

crisis

 Increases heart rate, dilates airways, increases blood pressure, inhibits digestion, and stimulates production of adrenaline

continued on next slide

Autonomic Nervous System (ANS)

• Parasympathetic branch

 Serves as counterbalance for

sympathetic nerves

 Causes heart rate to slow down, lowers blood pressure, and stimulates digestion

Somatic Nerves

• Mainly involved with conscious and voluntary activities of body

• Serve skin and skeletal muscles

 Carry information from sensory receptors of skin

• Such as touch, temperature, pressure, and pain

 Carry motor commands to skeletal

muscles

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Nervous System Combining Forms

• alges/o – sense of pain

• angi/o – vessel

• arteri/o – artery

• astr/o – star

• cephal/o – head

• cerebell/o – cerebellum

• cerebr/o – cerebrum

• clon/o – rapid contracting and relaxing continued on next slide

Nervous System Combining Forms

• concuss/o – to shake violently

• crani/o – skull

• cyt/o – cell

• dur/o – dura mater

• electr/o – electricity

• encephal/o – brain

• esthesi/o – sensation, feeling

• gli/o – glue continued on next slide

Nervous System Combining Forms

• hemat/o – blood

• hem/o – blood

• hydr/o – water

• isch/o – to hold back

• later/o – side

• lumb/o – low back

• medull/o – medulla oblongata

• mening/o – meninges continued on next slide

Nervous System Combining Forms

• meningi/o – meninges

• ment/o – mind

• my/o – muscle

• myel/o – spinal cord

• neur/o – nerve

• poli/o – gray matter

• pont/o – pons

• radicul/o – nerve root continued on next slide

Nervous System Combining Forms

• scler/o – hard

• spin/o – spine

• thalam/o – thalamus

• thec/o – sheath

• tom/o – to cut

• ton/o – tone

• vascul/o – blood vessel

continued on next slide

Nervous System Combining Forms

• ventricul/o –ventricle

• vertebr/o – vertebra

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Additional Suffixes

• -al pertaining to

• -algia pain

• -ar pertaining to

• -ary pertaining to

• -asthenia weakness

• -cele protrusion

• -eal pertaining to

• -ectomy surgical removal continued on next slide

Additional Suffixes

• -gram record

• -graphy process of recording

• -ia condition, state

• -ic pertaining to

• -ine pertaining to

• -ion action

• -itis inflammation

• -logy study of continued on next slide

Additional Suffixes

• -nic pertaining to

• -oma tumor, swelling

• -osis abnormal condition

• -otomy cutting into

• -paresis weakness

• -pathy disease

• -phasia speech

• -plasty surgical repair continued on next slide

Additional Suffixes

• -rrhaphy suture

• -taxia muscle coordination

• -tic pertaining to

• -trophic pertaining to development

Additional Prefixes

• a- without

• an- without

• anti- against

• bi- two

• de- without

• dys- abnormal, difficult

• endo- within

• epi- above continued on next slide

Additional Prefixes

• hemi- half

• hyper- excessive

• intra- within

• mono- one

• para- abnormal, two like parts of a pair

• poly- many

• quadri- four

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Additional Prefixes

• semi- partial

• sub- below

• un- not

continued on next slide

Building Anatomical Terms

• Cerebellar



 Pertaining to the cerebellum

• Encephalic



 Pertaining to the brain

cerebell/o + -ar

encephal/o + -ic

continued on next slide

Building Anatomical Terms

• Cerebrospinal



 Pertaining to the cerebrum and spine

• Intrathecal



 Pertaining to within the meninges

cerebr/o + -al+ spin/o

intra- + -al+ thec/o

Building Signs and Symptoms Terms

• Quadriplegia



 Paralysis of four (extremities)

• Neuralgia



 Nerve pain

quadri- + -plegia

neur/o + -algia

continued on next slide

Building Signs and Symptoms Terms

• Dysphagia



 Difficulty with speech

• Anesthesia



 Condition of being without feeling or sensation

dys- + -phasia

an- + -ia+ esthes/o

Building Pathology Terms

• Polyneuritis



 Inflammation of many nerves

• Sclerosis



 Abnormal condition of being hardened

poly- + -itis+ neur/o

scler/o + -osis

continued on next slide

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Building Pathology Terms

• Myelomeningocele



 Protrusion of spinal cord and meninges

• Subdural



 Pertaining to under the dura mater

sub- + -al+ dur/o

+ -cele+ mening/omyel/o

Building Diagnostic Terms

• Tomography



 Process of recording cuts (cross-section views)

• Angiography



 Process of recording vessels

tom/o + -graphy

angi/o + -graphy

continued on next slide

Building Diagnostic Terms

• Electroencephalogram



 Record of brain's electricity

• Lumbar



 Pertaining to the low back

lumb/o + -ar

electr/o + -gram+ encephal/o

Building Therapeutic Terms

• Neurectomy



 Surgical removal of a nerve

• Neuroplasty



 Surgical repair of a nerve

• Neurorrhaphy



 Suture a nerve

neur/o + -ectomy

neur/o + -plasty

neur/o + -rrhaphy

Combining Forms Match Up

1. cephal/o

2. encephal/o

3. gli/o

4. myel/o

5. thec/o

a. brain

b. glue

c. head

d. spinal cord

e. sheath