Nervous system“Let’s get wired!”

Central Nervous System – CNS◦ Brain and spinal cord

Peripheral Nervous System◦ Outer region – cranial/spinal origination

Divisions

Afferent nerves – incoming senses

Efferent nerves – outgoing motor

A vs E

Somatic - skeletal

Autonomic – visceral – smooth/cardiac/glands◦ Sympathetic – fight or flight response – immediate

threat◦ Parasympathetic – resting/regroup activities

Innervation

Skull

Meninges◦ Dura - epidural/subdural space◦ Arachnoid – subarachnoid space◦ Pia

Anatomy of the brain and spinal cord

Protection of the brain and spinal cord Circulates chemicals for internal brain function

– ie. CO-2 changes will cause medulla oblongata to accommodate respiratory function to meet body needs for homeostasis

Mainly found in subarachnoid space and ventricles (4) two in cerebrum, one medial/below these, and one in cerebellum (brainstem)

Formed in choroid plexus – extracted from blood

Cerebrospinal fluid

Formed in choroid plexus Ventricles Central canal/subarachnoid space Absorbed back into the blood

Normal adult CSF fluid is 140 ml

Circulation of CSF

CSF from subarachnoid space in L3-4

Pt. in R/L lateral fetal position or sitting on bedside

Pt. remains flat X 12 hrs. after procedure

Blood patch sometimes required

Tests for infection, disease

Lumbar puncture

Epidural

Congenital / tumor

Ventricles malfunction and disallow normal CSF flow

1-3:1000 births

Hydrocephalus

Low intensity radiation

Ventricula

 

1.Describe the difference between a spinal block and

an epidural.2. What is “hydrocephalus” and how can it be treated?

Protected by vertebral column Extends from foramen magnum to the distal

end of the first lumbar (45 cm – 18 in.) Spinal cavity includes: cord, blood vessels,

adipose tissue, meninges, and CS fluid Split into two symmetrical halves – anterior

surface is deeper and wider than the posterior surface

Nerve roots project from each side of cord

Structure of the spinal cord

Dorsal nerve root – sensory information to cord

Ventral nerve root – motor information out of the cord

Each side of the cord the dorsal and ventral nerve roots join together to form a spinal nerve (peripheral)

Cont.

Conducts information to and from the brain

Integrator – reflex center – for all spinal reflexes

Refer to ascending/descending tracts pgs. 382-383

Spinal cord functions

One of the largest vital adult organs Weighs 3 lbs. 100 billion neurons/900 glia (support cells) –

also called neuoglia Mitotic division only occurs in-utero and first

few months post-natal Cells will mature, but not increase in

number Maturity by 18 y.o.

Brain

How would pre-natal malnutrition affect the

fetus?

Medulla oblongata Pons Midbrain Cerebellum Diencephalon Cerebrum

Brain – six divisions

BrainstemComposed of:Medulla oblongataPonsMidbrain

Underside of the brain, showing the brainstem and cranial nerves

Internal view of the lower brain

Homonculus, a sensory map of your body. The homunculus looks rather strange because the representation of each area is related to the number of sensory neuronal connections, not the physical

size of the area.

Homonculus, a sensory map of your body. The

homunculus looks rather strange because the

representation of each area is related to the number of

sensory neuronal connections, not the

physical size of the area.

Medulla oblongata Attaches to spinal cord An extension of the spinal cord above the

foramen magnum One inch in size Separated from the pons by horizontal

groove Controls cardiac, respiratory and vasomotor

function Non-vital reflexes – vomiting, cough, sneeze

swallow

Above the medulla oblongata Motor control Sensory analysis Reflex mediator for the 5th-8th cranial nerves Helps with respiratory regulation

Pons

Mesencephalon

Above the pons and below the cerebrum

Vision, hearing, eye movement, body movement

Midbrain

Second largest part of the brain Located below the posterior section of the

cerebrum Responsible for movement coordination –

smooth, precise and steady as to force, rate and extent

Posture Balance – equilibrium receptors from ear

Functions of the cerebellum

Abscess, hemorrhage, tumor, trauma Ataxia – muscle incoordination Hypotonia Tremors Gait disturbance Balance disturbance – staggering, lurching,

raising foot to high to step, bringing foot down very hard

Disease of the cerebellum

Between the cerebrum and midbrain

Includes thalmus,hypothalmus, optic chiasma, and pineal body

Also known as the “emotional brain” or limbic system

Diencephalon

Processes auditory and visual signals Relay station for sensory perception to

cerebrum Conscious recognition of pain, temperature

and touch Partly responsible for emotions by

associating sensory impulses with feelings of pleasant vs unpleasant

Part in arousal/alerting mechanism Part in complex reflex movement

Thalamus

Autonomic center – visceral Sense of smell Link between mind and body Pleasure/reward center – eating, drinking, sex Relay station between cerebral cortex and autonomic

centers Mind over matter philosophy – psychosomatic disease –

positive/negative Regulates pituitary – renal function Hormone regulation Maintains wake state Appetite regulation Regulation of body temperature

Hypothalmus

Above the midbrain Looks line pine cone Function not well understood Regulates biological clock Produces melatonin – synchronize various

body functions with each other and external stimuli – such as onset of puberty and menses – also helps with light perception – called the “third eye”

Pineal body

Complete handoutDue next class!

Cerebrum – Cerebral Cortex

Largest portion of the brain Two halves separated by the longitudinal

fissure Surface – gray matter 1/12-1/6” thick Six layers containing millions of axon

terminals synapsing with dendrites and neurons

Convolutions (gyrus) Between gyri lie fissures (deeper grooves)

or sulci (shallow grooves)

Cerebral cortex

Fissues and imaginary boundaries divide each hemisphere into 5 lobes

Four are named after cranial bone plates, the fifth is called the insula (island of Reil) hidden from view in the lateral fissure (see diagram pg 391)

Interior of the cerebral cortex is the white matter with a few small areas of gray matter

Known as basal ganglia

Cont.

Three tracts allow for communication within the white matter

Projection – sensory and motor Association – most numerous – from one

convolution to the other – same side Commissural – from one hemisphere to the

other

Cont. –

Pg.393 What part of the brain is injured if pt. exhibits

these symptoms: Difficulty talking Lack of hearing Can’t feel hot temperature to fingers Blurred vision Slurred speech Can’t move legs Can’t stick out tongue

Function areas of the brain

Librarywww.can-do.com/uci/ssi2001/cranial.html

Touch, pressure, temperature, body position (proprioception) – somatic senses

Vision, hearing – special senses

Combination of both senses helps the brain to perceive images and relationships – (ie, ice cube in the hand, nail in foot)

Sensory function of the cortex

Voluntary movements – complex – requires great coordination of peripheral nerves and cerebral cortex

Precentral gyrus in frontal lobe responsible for most motor function

Motor function of the cortex

Consciousness – state of awareness – Mainly controlled through centers in the

brainstem (reticular activating system) and thalamus receiving messages from the spinal cord and then to the cerebral cortex

Without constant stimulation of the reticular system, consciousness cannot be maintained

Certain drugs depress this system and produce sleep – barbiturates

Drugs to stimulate this system are called amphetamines

Integrative functions

Sleep

5 stages -

Two major divisions: Slow-wave sleep and Rapid eye movement

SWS – dreamless

REM – dream state

Cont.

What is the difference between REM and NREM sleep?

Which one is only about 5 minutes?

What phase of sleep produces radical an crazy dreams?

What is the purpose of sleep according to this author?

Answer the following:

Anesthesia

Drug induced

Cont.

Coma

Trauma, disease, tumor growth, bleeding

Cont.

Glasgow Coma Score

Eye Opening (E) Verbal Response (V) Motor Response (M)

4=Spontaneous3=To voice2=To pain1=None

5=Normal conversation4=Disoriented conversation3=Words, but not coherent2=No words......only sounds1=None

6=Normal5=Localizes to pain4=Withdraws to pain3=Decorticate posture2=Decerebrate1=None

Total = E+V+M

Rate this patient Fetal position Mumbling Says “ouch” to pinch

Smooth extension of arm when asked

Stares at clinician

No answer when asked name

Rate this patient

No response to pin prick

Constant grunting sounds

Face grimaced – eyes closed

Rate this patient

Meditation

Higher wakeful state

Provides relaxation/alertness

Yoga

Cont.

Ability to speak and write words

Frontal, parietal, temporal lobes

Left hemisphere contains these areas in 90% pop. – remaining 10% in right or both

Aphasia

Language

Latin - Border of fringe

Medial surface of the cerebrum

Anger, fear, pleasure, etc.

Expression of emotion is combination of many cortical structures

Rage is thought to occur when limbic activity is not modulated by other cortical areas

Emotions – limbic system

Major mental activities

Short-term – seconds/minutes

long-term – past occurrences

Temporal, occipital, parietal

Memory

BikeArrowAlligatorKiteButterflyHouseFlowerHat NailCoatSkeletonNose

Remember these terms!

Stem next to brain stem

12 pairs

Pass through a foramen

Peripheral

Cranial nerves

Create a mnemonic to remember the

cranial nerves Your group will share with the class.

Game time!Get into groups of four

Internet site challenges!

Electroencephalogram

Delta – slow - sleep

Beta – fast – thinking actively

Alpha – fast – relaxed/quiet

During seizure, these waves are synchronized and have rapid electrical spikes

EEG interpretations:

MRI

Thalamic infarct

Computerized tomography

Positron-emission tomography

Stroke – interruption of blood flow

Seizure – tumor, chemical imbalance, drugs, idiopathic

Dementia – changes in brain function1. Alzheimer’s2. Huntington’s disease3. AIDS4. Creutzfeldt-Jacob disease5. Bovine spongiform encephalopathy – Mad cow6. Alcoholism 7. Anemia

Disorders of the brain

Alzeimer’sFINISHED FILES ARE THE RE-SULT OF YEARS OF SCIENTIF-IC STUDY COMBINED WITH THEEXPERIENCE OF YEARS...

How many “F’s”?

I fear I am not in my perfect mind.Methinks I should know you and know this man;Yet, I am doubtful; for I am mainly ignorantWhat place this is; and all the skill I haveRemembers not these garments; nor I know notWhere I did lodge last night. Do not laugh at me.(William Shakespeare (1605) King Lear, Act IV, Scene 7)

Criteria Runs – 2-25 year (usually 4-8) Gradual degenerative disease 4.8 mil. Americans Memory loss Brain death of cells

Genetic Degeneration of nerve cells in the brain tMT for emotional and movement problems No cure

Huntington’s

1 per mil. Familial Confusion Dementia Progressive jerky movements

Don’t eat cow!

Mad Cow

Brain ID assignment:Groups of two - label the brain as to

function and control using various colors to represent your learning

Include the following:

Brain Game ID

Make a line in these colors to indicate location and use an identifying term

Speech - red Sight - dark blue Hearing - light green Touch - dark green Sound - yellow Movement - pink Speech - black Taste - orange

Balance - brown Posture – light blue Coordinated muscle

movement - purple Consciousness - red