Transcript The Brain - davis.k12.ut.us

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•
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was ipmorantt!
Introduction to Health Science
The Nervous System
(Regulatory System)
What is the nervous system
composed of?
• Brain
• Spinal Cord
• Nerves
• Sense Organs
• Receptors
Fun facts first!
What’s it made of?
• 77% Water
• 10-12% Lipids
• 8% Protein
• 1% Carbs
• 2% Soluble Organics
• 1% Inorganic Salt
There are…
• 100 Billion Neurons in the Human Brain
About The same amount…
• Of Stars in the Sky
The left hemisphere has…
• 186 million more
neurons than the
right hemisphere.
750-1000ml of blood flow…
• through the brain every minute.
• This is about 3 full soda cans!
The brain can stay alive…
• 4-6 minutes
without
oxygen!
The slowest neurons in the brain…
• travel at 260 MPH.
• As “slow” as today’s fastest car!
(Clocked at 253 MPH)
More electrical impulses…
• Are generated in
one day by a
single human
brain than all the
telephones in the
world.
The human brain has…
• 70,000 thoughts
in an average
day.
FUNCTIONS OF
THE BRAIN
(or noodle)
The Basic Functions of the Nervous System
• Sensation
– The ability of the nerves to detect stimuli, such as
pressure, temperature changes, taste, smell or
light, and send a message in the form of impulses
to the brain and spinal cord.
Integration
• The nervous system receives and
interprets sensory stimuli from the body
and determines an appropriate response
to those stimuli.
Movement
• The ability of the brain to send impulses
through motor nerves to muscles and
glands to cause movement or secretion
of hormones.
Left
vs.
right
• Logical
• Creativity
• Mathematical
• Imagination
• Linguistic
• Speech
• Artists
• Dreamers
• Visual
Spatial
The Brain
• The brain is responsible for analyzing
information, processing information and relaying
messages to the rest of the body. It is the main
control center of the body.
• Along with the spinal cord, it forms the body’s
Central Nervous System or CNS.
• The brain is composed of three main parts:
– Cerebrum
– Cerebellum
– Brain Stem
Brain Structures and Functions
• Cerebrum
– The cerebrum is the largest part of the brain. It has
two distinct halves called hemispheres. The
cerebrum has many folds and grooves to increase the
number of nerves found in the brain.
• The cerebrum is divided into four lobes.
–
–
–
–
Frontal Lobe
Parietal Lobe
Temporal Lobe
Occipital Lobe
The Basic Structures of the
Nervous System
• Frontal Lobe
– The frontal lobe controls skeletal muscle movement,
interprets the sense of smell, is responsible for our
personalities, and our ability to learn, think, problem solve
and concentrate.
• Parietal Lobe
– The parietal lobe interprets many of our senses including
taste, touch, temperature, and pain.
• Occipital Lobe
– The occipital lobe interprets the sense of sight.
• Temporal Lobe
– The temporal lobe interprets the senses of balance and
hearing. It also contains structures (such as the
hippocampus) which store memory.
Cerebellum
• The cerebellum is the second largest part
of the brain. In fact, cerebellum means the
“little cerebrum.” It is located at the back
of the head below the cerebrum.
• It functions to coordinate the muscular
movements and helps the muscles move
gracefully and efficiently. It also helps with
the body’s ability to balance.
Brainstem
• The brain stem is located below the cerebellum and
connects the spinal cord to the brain.
• The brain stem is composed of two structures – the
medulla oblongata and the pons.
– The medulla oblongata is continuous with the spinal cord
and helps to regulate the heart beat, blood pressure,
breathing, swallowing, hiccupping, and vomiting. It also
relays nerve impulses between the brain and the spinal
cord.
– The pons is a small bulge above the medulla oblongata. It
is important to help us regulate the rate and depth of
breathing.
How does the
brain
communicate
with the rest
of the body?
The Spinal Cord
• Along with the brain, it is part of the Central
Nervous System.
• It is the major communication link between the
brain and the rest of the body.
• It can process many reflexes – unconscious,
automatic responses to stimuli.
• There are 31 pairs of spinal nerves which branch
from the spinal cord to control such processes as
breathing, arm movement, and leg movement.
Cerebrospinal Fluid
• CSF is a clear, watery fluid which bathes the
brain and the spinal cord to protect it by acting
as a shock absorber.
• CSF allows for the exchange of nutrients and
waste products between the blood and the
nervous tissue.
• CSF circulates between the two layers of the
meninges, through the center of the spinal cord,
and through large openings in the brain
(ventricles).
Meninges
• A set of three layers of connective tissue that
enclose the brain and spinal cord. They are
located under the skull and attach directly to the
brain.
• Meninges help to provide a small amount of
protection to the brain and spinal cord.
• Cerebrospinal fluid circulates between two layer
of the meninges.
neurons
Nerves
• Nerves (neurons) are the basic units of
structure and function for the nervous
system.
• Nerves are capable of sending electrical
messages called impulses.
• There are two main types of nerves:
– Sensory nerves
– Motor nerves
Sensory Neurons
• Specialized to detect changes
and carry impulses to the
brain and spinal cord from the
sense organs.
• Example: pressure or heat
Motor neurons
• detect changes
and carry impulses
away from the
brain and spinal
cord that signal
muscle
contractions…
Nerve Structure
• There are three basic parts of a neuron:
– Dendrites
• Short, branchlike extensions which conduct electrical
signals toward the cell body.
– Cell Body
• Contains large nucleus and other cellular organelles.
– Axon
• Extends from the cell body. Responsible for carrying
nerve impulses to other neurons, muscles or glands.
CYK
Please put your notes away and your thinking cap on.
Rules:
• Use your motor neurons (raise your hand) if you
think you know the answer!
• If you get it right then I will feed your sensory
organs.
Part of the nervous system that starts with a
“B”
#1
Name that Lobe
interprets many of our senses
#2
The spinal cord has how many paired spinal
Nerves?
#3
Name that Neuron:
(Senses heat)
#4
Part of the nervous system that starts with an
“N”
#5
Clear liquid that acts as a shock absorber to
protect the brain
#6
Name the part that connects the
brain to the spinal cord
#7
Known to as the “little cerebrum”:
#8
Nervous System
DISEASES AND DISORDERS
Describe Diseases Disorders of the
Nervous System
•
Meningitis
– Meningitis is an infection that causes the
inflammation of the brain and spinal cord coverings.
Most common forms are bacterial or viral.
– Symptoms: fever, chills, headache, nausea,
vomiting, stiff neck
– Treatment: Antibiotics for bacterial meningitis
Epilepsy
• Epilepsy is a brain disorder involving
repeated seizures of any kind. Seizures
are episodes of disturbed brain
function that cause changes in
attention or•behavior.
Symptoms:
• Loss of consciousness
• Staring spells
• Violent convulsions.
• Treatment:
• Varies depending on the
cause.
• May be controlled by
medications.
Concussion
• Post traumatic impairment of
neural function caused by a
direct blow to the head resulting
in bruising of the brain.
– Symptoms may include headache, loss of
consciousness, ringing of the ears, nausea,
irritability, confusion, disorientation,
dizziness, amnesia or difficulty
concentrating.
– Treatment may include removal from
play, rest avoiding re-injury, medications
for pain, physical therapy and relaxation.
Stroke
• Stroke, also known as a CVA or cerebrovascular
accident, occurs when there is an interruption of
the blood supply to any part of the brain.
• Symptoms appear suddenly and
can include weakness or paralysis
of an extremity, numbness, vision
changes, slurred speech,
difficulty swallowing and loss of
memory
• It is important to get immediate
care to reduce permanent
complications. Physical therapy
and/or occupational therapy may
be needed.