Download The Nervous System

The Nervous System is divided into
the
Central Nervous system
Brain
Spinal cord
Brain
• Organ that enables us to have thought ,
emotions ,memory and sensory
experiences.
Sagittal Section of the Brain
What does the brain do?
Everything!!!!!•
Regulates and coordinates body activities.
How?
• Sensory impulses are received via afferent nerves (registered as
“sensations”). When a sensory impulse is received the brain
analyzes the impulse, reactions are generated and sent off through
efferent nerves to muscles and glands to stimulate a reaction to the
received input.
• The brain is the center for consciousness memory, ability
to reason, judgment , perception and emotion.
and ,without even having to
think about it…
Reflex centers automatically control body
activities.
• Cardiac activity
• Vasomotor activity
• Respiratory activity
Are you right brained strong or
left brain strong?
Central Nervous System
• Comprised of the Brain and the spinal
Cord
And the Peripheral Nervous
System
Neurons that originate in the spinal column
and reach out to every area of the body
and back to the spinal cord . These
neurons receive messages and send
messages.
The Peripheral Nervous System
Phase One of Brain
Development
• The first phase of brain development in the fetus is neuro
genesis. During neurogenesis, new neurons are formed .
Neurons are nerve cells that conduct electrical impulses
throughout the body. In babies, more than 100 billion
neurons are formed before birth, with as many as 50,000
neurons being formed every second during fetal brain
development. These newly developed neurons allow the
infant brain to link events to memories that occur at the
same time. This is known as integration. This process
continues into early adulthood!
Phase Two
• The second phase of brain development is
neural migration, also known as neuronal
migration. In neural migration, the newly formed
neurons in the brain are relocated to different
areas of the brain dependant on their assigned
function. This process begins while a baby is still
in the womb and ends around its 10th month of
life.
Phase Three
• The third phase of brain development in babies is called
myelination. Myelin is the coating that covers each
neuron's axon ( a long, arm-like fiber that protrudes from
the neuron). Myelin forms a protective sheath around the
neuron that keeps it from harm and allows it to be more
effective in transmitting signals to other neurons.
Myelination begins in the developing fetus and continues
into early adulthood.
Phase Four
• Synaptogenesis is the fourth phase of brain development
in babies. Synapses are the spaces where two neurons
connect. When an infant is born, each neuron has 2,500
synapses, which totals 50 trillion synapses in the infant
brain. By the age of 1, this number increases to 15,000
synapses per neuron for a total of 1,000 trillion
synapses. Synaptogenesis is the formation of new
synapses. When synapses are created to a high degree
through new experiences, they allow the central nervous
system to send and receive messages much more
quickly between nerve cells. Like neurogenesis,
synaptogenesis continues into adulthood.
Phase Five
• Pruning is the fifth and final phase of brain development
in babies. During this phase, neurons that have become
weak or obsolete due to disuse are destroyed while
those that have proven to be valuable through repeated
use are strengthened and given room to expand. This is
also known as neural plasticity. Which neurons are
pruned is based on the child's experiences and occurs
most often between the ages of 3 and 16.
When someone is labeled “very
cerebral”…what do you think
that means?
The cerebrum is 7/8 of brains weight --There are two hemispheres – right and
left :
THE LEFT HEMISPHERE CONTROLS
THE RIGHT SIDE OF THE BODY.
THE RIGHT HEMISPHERE CONTROLS
THE LEFT SIDE OF THE BODY.
5 Parts of the brain
• Cerebrum ( A.K.A. Cerebral cortex A.K.A.
Cortex)
• Cerebellum
• Brainstem
• Pituitary
• Hypothalmus
The brain weighs about three
pounds.
It is about the consistency of butter.
It needs a great percentage of the bodies
Oxygen to function normally.
It needs food to function as well.
It is folded in upon itself to increase the
surface area of the brain-high part-folds are
called gyrus.
Sulci are the separations between the lumps
of the brain.
Lobes-4 lobes in each
hemisphere….how many lobes
in total?
In case you missed it :
LOBES
The lobes of the Brain are:
Frontal
Parietal
Temporal
Occipital
Breakdown of structures and
functions
The three basic functions
performed by the Nervous
System are:
• Receive sensory input from internal
and
external environments-ie:feeling a burning
sensation when you touch a flame
• Integrate the input –Develop a response
• Respond to stimuli –Pull your hand away
from the flame!
Autonomic System-Involuntary
(ie: The things that are
happening while we are asleep)
Sympathetic-reacts to stimuli
Parasympathetic-returns body
to homeostasis
Autonomic Nervous System
Somatic System
Voluntary Actions –skeletal muscle control
Afferent –message sent from senses to
Nervous system
Efferent- message sent from nervous system to skeletal
muscle
Input and Action
Cells of the Nervous System
• Gray matter- Neurons
• White matter- Glial- Processes that form
tracts that connect various parts of the
brain.
Neurons
• The neuron is the functional unit of the
nervous system. Humans have about 100
billion neurons in their brain alone! While
variable in size and shape, all neurons
have three parts.
Neuron
Neurons
• 1)The dendrites receive information from
another cell and transmit the message to
the cell body.
• 2)The cell body contains the nucleus,
mitochondria and other organelles typical
of cells and sends the message along to...
• 3)The axon conducts messages away
from the cell body.
neuron
NEURON
Synapse and neurotransmitters
• The spaces between neurons is called the
synaptic junction .
• Neurotransmitters are chemicals that allow
messages to be carried from one nerve to
the next or block messages being sent.
•
•
Dopamine - Serotonin -Norepinephrine - GABA - Enkephalins
Dopamine is often called the "Feel Good Neurotransmitter!
When we have enough Dopamine we have . . .
Feelings of pleasure
Feelings of attachment/love
Sense of altruism (unselfish concern for the welfare of others)
Integration of thoughts and feelings
.Serotonin When we have enough serotonin, we feel emotionally stable, we can
sleep, we can sort out the feelings and determine in a logical manner if there is a
threat present.
Norepinephrine Norepinephrine, also known as noradrenaline, is a neurotransmitter
found in the sympathetic nervous system.
The sympathetic nervous system stimulates the heart, blood vessels, sweat glands,
the large internal organs, and the adrenal medulla in the brain.
GABA GABA (gamma-aminobutyric acid) is the most important and the abundant
inhibitory neurotransmitter in the brain (it's actually an amino acid classified as a
neurotransmitter).
Enkephalins One of the three major families of endogenous opioid peptides. The
enkephalins are pentapeptides that are widespread in the central and peripheral
nervous systems and in the adrenal medulla. Enkephalins functions in Psychological
Pain Relief
Covering of Neurons
• Myelin Sheath –protective coating on
axon of nerves . There are many
progressive and chronic diseases that
destroy the myelin sheath (ie : M.S.).
Cranial Nerves
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olfactory- smell
optic- vision
occut motor- eyelid/ pupil
trochlear- eye rotation
trigeminal – facial sensation
abducans- eyes
facial- facial movement
vestibular- hearing
glossopharangeal- taste- swallow
vagus- vocal cord swallowing speech
spinal accessory- head rotation
hypoglossal- Tongue control
On old olympus towering tops a finn vith german Valked and
hopped!
Some key terms:
• Neurons-nerve cells of the nervous systembillions upon billions in our bodies
• Glial Cells-the “glue”of the brain
• Neurotransmitters-The chemicals manufactured
by the body that allow nerve cells to transmit (or
send) messages all around the body from
neuron to neuron
• Hormones-Chemicals that the body makes that
control all of the functions of the body
• Homeostasis-Balance that is maintained
(ideally) between all of the systems of the body
Protection
• Skull-Bone
• Cerebrospinal Fluid-fluid the brain is floating in that acts as a
cushion and supplies necessary nutrients
• Meninges-The gift wrap of the brain-three canvas like layers
•
Dura mater-outer
•
Arachnoid-middle
•
Pia mater-innermost
• Vertebrae
• Reflexes
• Ventricles- cavities of brain filled with
cerebro spinal fluid formed by the
choroid plexuses in the walls and roof
of ventricles.
CSF provides1) cell nourishment
2) removal of waste
3) cushioning
Ventricles
When a good nervous system
goes bad…..
There are hundreds of “diseases” of the
nervous system. Some of these diseases
are genetic , some are trauma induced,
some have environmental causes.
Google a list of ICD 9 codes for “diseases of
the Nervous System". As you will see, it is
extensive!
Seizures-can be from birth or
may develop as a result of
traume or illness (even fever!)
• Seizures are a symptom of something going on
in the brain. Seizures are caused by
disturbances in the electrical activity of the brain.
Seizures may be related to a brain injury or a
family tendency, but most of the time the cause
is unknown.There are many different types of
seizures.
• Go to the website Epilepsy.com and
watch the brief slideshow on Seizure first
aid!
• Loosen clothing around the person's
neck.
• If someone is having a seizure:
• Do not try to hold the person down or restrain
them. This can result in injury.
• Do not insert any objects in the person's mouth.
This can also cause injury.
• Reassure concerned bystanders who may be
upset and ask them to give the person room.
• Remove sharp objects (glasses, furniture, and
other objects) from around the person to
prevent injury.
• After the seizure, it is helpful to lay the person
on their side to maintain an open airway and
prevent the person from inhaling any
secretions.
• Reassure concerned bystanders who may be upset and
ask them to give the person room.
• Remove sharp objects (glasses, furniture, and other
objects) from around the person to prevent injury.
• After the seizure, it is helpful to lay the person on their
side to maintain an open airway and prevent the person
from inhaling any secretions.
• After a seizure, the person may be confused and should
not be left alone.In many cases, especially if the person
is known to have epilepsy, it is not necessary to call 911.
• Call 911 if the seizure lasts longer than 5 minutes, or if
another seizure begins soon after the first, or if the
person cannot be awakened after the movements have
stopped. If you are concerned that something else may
be wrong, or the person has another medical condition
such as heart disease or diabetes, you should contact a
doctor immediately.
STROKE
Brain Illnesses
Meningitis
Encephalitis
Brain Tumors-benign or malignant
Cerebral vascular Accident (C.V.A.)
Symptoms-Headache
, Nausea , Vomiting
Fever ,Blurred Vision ,Imbalance, Confusion, Emotional Outbursts ,
unequal pupils.
Neurological issues
Tumors – Benign
Malignant
Infections- Viral
Bacterial
AneurysmsRuptured Blood Vessel
Stroke –
C.V.A.-Clot or Ruptured Blood Vessel
Alzheimer's / Dementia –
tangled plaques in brain
Normal brain versus Alzheimer's
brain
More Nervous System
Disorders
Amyotrophic Lateral Sclerosis –Lou gehrigs disease
Multiple Sclerosis
Huntington Chorea•
Adreno leuko-dystrophy-A specific treatment for X-linked adrenoleukodystrophy is not available,
but eating a diet low in very-long-chain fatty acids and taking special oils can lower the blood
levels of very-long-chain fatty acids.
•
These oils are called Lorenzo's oil, after the son of the family who discovered the treatment. (Try
to see the movie “Lorenzo’s Oil “ ,it is fantastic!)This treatment is being tested for X-linked
adrenoleukodystrophy, but it does not cure the disease and may not help all patients.
Cerebral Palsy-Cerebral palsy (CP) is a non‐progressive lifelong condition resulting from
damage to the newborn brain. Most infants have spasms (spasticity) affecting at least
one leg that prevents normal movement.
Remember-C.V.A. Symptoms
!) Slurred Speech
2)Headache
3)Blurred Vision
4)Difficulty Swallowing
5)Facial Numbness
6)Peripheral Numbness
7)Hemiplegia (one side of the body is paralyzed)
What do you do??? Don’t
Panic..call 911
CALL
911ca