Transcript The Nervous System - Practicum-Health-II-2011-2012

The Nervous
System
What is it?
A
highly complex organized
system that coordinates all of
the activities of the body.
This system enables the body to
respond or adapt to changes
that occur both inside and
outside the body.
Components of the
Nervous System
Brain
Spinal
Cord
Nerves
Nerves
NERVES
 Are
a combination
of many nerve
fibers located
outside the brain
and spinal cord.
Their function is to
relay messages to
all the body
muscles and
glands. (muscles
power the body
DIRECTIONS OF
NERVE IMPULSES
 Afferent
(sensory) nerves carry
messages from all parts of the body
to the brain and spinal cord.
 Efferent (motor) nerves carry
messages from the brain and spinal
cord to the muscles and glands.
 Associative (internuncial) nerves
carry both sensory and motor
messages.
The Cell of the
Nervous System
Neurons
The
neuron is the Basic
functional unit of the nervous
system.
Humans have about 100
billion neurons in their brain
ALONE.
3 Parts of a Neuron
Body – contains the nucleus
(maintains the functionality of the
cell)
Dendrite – (dendritic tree) carry
impulse to cell body
Axon – a single nerve fiber carries
impulse away from the cell
Cell
Myelin Sheath
Axons
have a lipid or fat layer
called the myelin sheath.
They increase the rate of
impulse transmission and
insulates and maintains the
axon.
For
communication
between neurons to occur,
an electrical impulse must
travel down the axon to the
synaptic terminal.
Impulses
coming from one
axon “jump” the synapse to
get to the dendrite of
another neuron, which will
carry the impulse in the
right direction.
SYNAPSES
 ARE
spaces between the Dentrites and
the Axon.
What allows for the
jump across the
sypnase between
dentrites and axons?
….

NEUROTRANSMITTERS –
located at the end of each axon allow
the nerve impulses to pass from one
neuron to another. These messages
(impulses are able to follow many
different routes.
Information is
moved around the
brain, from nerve
cell to nerve cell,
by means of
chemical
substances, called
neurotransmitters
Parts of the Nervous
System
 The
nervous system is broken down into
2 major parts.
 Central Nervous System – consists
of the brain (encepha/o) and the
spinal cord (spondyl/o)
 Peripheral Nervous System –
consists of the nerves.
subdivision: AUTONOMIC
NERVOUS SYSTEM
AUTONOMIC
NERVOUS SYSTEM
TWO PARTS
Sympathetic and
Parasympathetic
These two systems work
together to maintain a balanced
state (homeostasis)
SYMPATHETIC
In
times of emergency, this
system prepares the body to
act in two ways:
Fight or Flight
by: Increasing
heart rate
respiration
blood pressure
PARASYMPATHETIC
 This
system counteracts, the
actions of the sympathetic system
 BY slowing down the
Heart Rate
Respiration Rate
Lowering blood pressure
AND Increasing activity in
the Digestive System
Central Nervous
System
Consists
of:
Brain
Spinal
Cord
Brain Hemispheres
Your
brain is divided into left
and right hemispheres.
The right side of your brain
controls the left side of your
body.
The left side of your brain
controls the right side of your
body.
Left Brain/
Right Brain
The Brain
 The
brain is a mass of nerve tissue well
protected by membranes and the
cranium.
 It is made up of several sections.






Cerebrum
Cerebellum
Diencephalon
Midbrain
Pons
Medulla oblongata
Sections of the
Brain
Cerebrum
The
largest and highest
section of the brain.
The outer part is arranged in
folds, called convolutions,
and separated in lobes.
Functions of the
Cerebrum
 Reasoning
 Thought
 Memory
 Speech
 Sensation
 Sight
 Smell
 Hearing
 Voluntary
body movement
Functions of the
Cerebellum
Muscle
coordination
Balance
Posture
Muscle tone
Diencephalon
 The
structure that lies between the
cerebrum and the midbrain.
 It contains two structures:
 Thalmus- directs sensory
impulses to the cerebrum.
 Hypothalmus-regulates and
controls many of the functions of
the body.
Midbrain
The
section located below
the cerebrum at the top of
the brainstem.
Major Function:
 conducting impulses
between brain parts
Pons
 The
section located below the
midbrain and in the brain stem.
 Functions:
 Conducting messages to other
parts of the brain
 Certain reflex actions
 Assists with respiration
Medulla Oblongata
 The
lowest part of the brain stem.
 It connects with the spinal cord.
 Functions: Regulation of
 Heartbeat
 Respiration
 Swallowing
 Blood pressure
Lobes of the Brain
Lobes of
the brain
Creation
Wiki, the
encyclop
edia of
creation
science
Spinal Cord
Continues
down from the
medulla oblongata and ends at
the first or second lumbar
vertebrae.
It is surrounded and protected
by vertebrae.
Functions of the
Spinal Cord
Responsible
for many reflex
actions and for carrying
messages to and from the brain
to the nerves that go to the
organs and glands.
MENINGES
There are three membranes that cover
and protect the brain and spinal cord.
1. Dura mater – outer layer
2. Arachnoid membrane – delicate and
web-like
3. Pia mater – closely attached to the
brain and spinal cord; contains the
blood vessels that nourish the nerve
tissure.
VENTRICLES
There are FOUR hollow spaces that
connect with each other and with the
space under the arachnoid membrane.
The ventricles are filled with a fluid called:
CEREBR0SPINAL FLUID
This fluid serves as a shock absorber


Carries nutrients, removes metabolic waste
Absorbed into the blood vessels of the dura
mater, returned to the bloodstream via the
arachnoid villi
DISEASES AND
ABNORMAL
CONDITIONS
palsy – a disturburbance in
voluntary muscle action and is caused
by brain damage (due to lack of oxygen,
birth injuries, prenatal rubella(german
measles), and infections.
 Cerebrovascular accident (CVA)
(stroke) – cerebral hemorrhage due to
an aneurysm or occlusion or thrombus.
 Cerebral
– inflammation of the brain
due to virus or bacterium or chemical
agent.
 Epilepsy – or seizure syndrome;
abnormal electrical impulses in the
neurons of the brain.
 Hydrocephalus – an excessive
accumulation of cerebrospinal fluid in
the ventricles and sometimes, in the
subarachnoid space of the brain.
 Encephalitis
– inflammation of the
meniges of the brain and/or spinal cord
due to bacterium, virus, fungus, or
toxins (lead, arsenic, mercury)
 Multiple sclerosis – (MS) chronic,
progressive, disabling, condition due to
degeneration of the myelin sheath in the
CNS.
 Neuralgia – nerve pain due to
inflammation, pressure, toxins and other
diseases.
 Meninigitis
– results from a brain or spinal
cord injury that destroys neurons and
results in a loss of function and
sensation below the level of injury.
 Paralysis



Hemiplegia – one side of the body
Paraplegia – lower extremities
Quadriplegia – upper and low extremities
 Parkinson’s
disease – chronic,
progressive condition involving
degeneration of brain cells; includes
tremors
(herpes zoster) – acute
inflammation of nerve cells caused by
herpes virus; which also causes chicken
pox.
 Shingles
RELATED CAREERS
 Acupressurist
 Acupuncturist
 Anesthesiologist
 Chiropractor
 Diagnostic
imager
 Doctor of Osteopathic Medicine
 Electroencephalographic Technologist
 Electroneurodiagnostic Technologist
 Mental Health Technicians
 Neurologist
 Neruosurgeon
 Physical
Therapist
 Polysomnographic Technologist
 Psychiatrist
 Psychologist
Medical Terminology
Root word: myel/o denotes spinal cord or
bone marrow
Myelocele
hernail protrusion
Poliomyelitis
gray; inflammation
Myelomalacia
softening
Myeloplegia
paralysis
Myelogenous
produce/create
 Root
Word: encephal/o denotes brain
(inside) combined with cephal/o: head
Encephalitis
Encephalogram
Encephalopathic
Encephaloma
Encephalomalacia
inflammation
picture-tracing x-ray
disease; pertaining to
tumor
softening
Psychiatrics
Psychasthenia
Psychology
Psychosomatic
Psychophylaxis
treatment
without, strength
science, study of
body, pertaining to
protection, prevention
Root Word: algia,algesia; denotes pain or ache
Cephalalgia
Neuralgia
Arthralgia
Otalgia
Hyperalgesia
Analgesic
Gastralgia
Myalgia
Kinesalgia
Costalgia
head
nerves
joint
ear
above,excess
without, pertaining to
stomach
muscle
movement
rib
Root Word: neur/o, denotes the nerves or
nervous system
Neruobiology
Neuritis
Neuroma
Neuropathy
Neruosis
life, study of
inflammation
tumor, swelling
disease
disease condition
Root Word: cephal/o, denotes cranium
(head)
Cephalocele
Cephaloplegia
Cephalometer
Cephalic
Cephalocaudal
hernia
paralysis
measure
pertaining to
tail, pertaining
to
Medical
Abbreviations
Letter O
O2
ob or obs
od
oint
OJ
OOB
Meaning
oxygen
obstetrics
overdose
ointment
orange juice
out of bed
opp
OR
Ord
Orth
os
OU
oz
opposite
operating room
orderly
Orthopedics
mouth
each eye
ounce