The Nervous System

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The Nervous System

• The big picture gathers and processes
  information, responds to stimuli, and coordinates
  the workings of different cells.

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The Central Nervous System

• Consists of the brain and spinal cord, receives
  processes, interprets, and stores sensory
  information. Nose touch
• Spinal reflexes are automatic and require no
  conscious effort. Ex. Knee-jerk or finger on
  stove
• The neural circuitry underlying a reflex is a
  reflex arc.
• sensory neuron gtinterneuron (w/in the spinal
  cord)gtmotor neuron
• Ex. Scottie C-5 spinal cord injury. No way for
  sensory info to reach his brain.

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The Peripheral Nervous System

• Consists of all parts of the nervous system other
  than the brain and spinal cord. It handles the
  central nervous systems input and
  output.Shoulder, elbow, finger touch
• Sensory nerves carry messages from receptors to
  the brain.
• Motor nerves carry messages from the central
  nervous system to muscles, glands, and internal
  organs.dollar drop

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PNS cont

• 3. The peripheral nervous system is divided into
  the skeletal (somatic) and autonomic branches.
• A. The skeletal (somatic) nervous system controls
  skeletal muscles and permits voluntary action.
  knee/slap
• B. The autonomic nervous system regulates blood
  vessels, glands, and internal organs. stop your
  heartbeat! Like automatic pilot.
• C. Although biofeedback can help people control
  voluntary responses, it is not clear whether they
  can learn to control autonomic responses directly.

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PNS cont

• 4. The autonomic nervous system is divided into
  opposing sympathetic and parasympathetic
  branches both are involved in emotion and
  stress.
• A. The sympathetic nervous system mobilizes the
  body for action and increases energy output.
  meeting a mountain lion
• B. The parasympathetic nervous system conserves
  energy and helps the body store it.
  Calms/conserves. Decrease heartbeat!

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Communication in the Nervous System The Nuts and
Bolts

• Neurons, or nerve cells, are the basic units of
  the nervous system, which are held in place and
  nourished by glial cells. They specialize in
  communication.
• A. The structure of the Neuron
• 1. The neuron has three main parts a cell body,
  dendrites, and an axon.
• 2. The cell body keeps the neuron alive and
  determines whether it should send a message to
  other neurons the dendrites of a neuron receive
  messages from other neurons and send them to the
  cell body the axon transmits messages away from
  the cell body to other neurons, muscles, or
  glands.

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Phrenology
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B. The Cerebral Cortex The Brains Thinking Cap

• 1. The cortex contains three-fourths of all the
  cells in the human brain. More cortex in
  humanswe arent on autopilot!
• 2. The occipital lobes contain the visual cortex,
  where visual processing occurs.
• 3. The parietal lobes contain the sensory cortex,
  where information about pain, touch, and
  temperature is processed.
• 4. The temporal lobes are involved in memory,
  perception, emotion, and language comprehension,
  and they contain the auditory cortex, which
  processes sound.
• 5. The frontal lobes are involved in judgment,
  planning, creating, and initiating, and they
  contain the motor cortex, which produces
  voluntary movement.
• head pointing

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The Motor Cortex cont

• 6. Those areas of
• the body requiring
• precise control
• (fingers, mouth, etc.)
• take up the most
• cortical space.

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The Cerebral Cortex cont

• 7. Damage to the
• frontal lobes may
• dramatically alter
• personality.
• (Phinias Gage)

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The Cerebral Cortex cont

• 8. The association cortex is the site of higher
  mental processes. 10 of our brain myth.

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A Question of Dominance

• Nearly all right-handed people and a majority of
  left-handers process language mainly in the left
  hemisphere, which also seems to be dominant in
  logical, symbolic, and sequential tasks.
• The right hemisphere is superior in
  visual-spatial ability and facial recognition.
  It is also involved increasing and appreciating
  art and music, and seems to have some language
  ability.
• Although some popular programs promise to enhance
  one or the other of your hemispheres abilities,
  in most real-life activities, the two hemispheres
  cooperate naturally with each contributing to our
  effectiveness.
• which side of the brain are you accessing?

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Which is your dominate side?

• Left Hemisphere
• Step by stem reasoning of info.
• Language
• Listening
• Writing
• Reading
• Mathematical calculations

• Right Hemisphere
• Visual/Spatial information
• Recognize complex patterns drawings
• Aptitude for music
• Expression recognition of emotion
• Recognizing faces
• Solving spatial relationship problems
• Symbolic reasoning
• Artistic activity

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Eavesdropping on the Brain

• Progress in understanding the brain depends on
  studies of brain damage, investigations that
  stimulate brain centers, and studies in which
  brain activity is measured, for example by means
  of the
• 1. Electroencephalogram (EEG)-traces electrical
  brainwaves. Ex how the brain responds to sound or
  sight.

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Eavesdropping on the Brain cont

• 2. positron-emission tomography (PET scan) shows
  consumption of sugar (glucose) as needed for
  brain activity.

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In men who had ADHD, PET scans showed that they
processed a memory task in visual areas in the
occipital lobe of the brain, as indicated by the
yellow spots in the left image. Non-ADHD men used
the temporal and frontal lobes, shown at right
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Eavesdropping on the Brain cont

• 3. Magnetic resonance imaging (MRI) uses
  magnetic fields radar waves to distinguish
  between different types of soft tissue.
• (Brain Structure)

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MRIS give detailed volumetric measurements of
specific regions of the brain. The volumetric
measurements of the caudate nucleus indicate a
smaller right caudate nucleus in ADHD boys in
comparison to normal boys Extensive and time
consuming measurements of the head and body of
the caudate nucleus and the frontal lobes have
supported their role in ADHD
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Eavesdropping on the Brain cont

• 4. Computed tomograph (CT) takes x-ray
  photographs that can reveal brain damage.

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The top picture shows a newborn with
hydrocephalus prior to its treatment. The darker
gray is CSF and the lighter gray rim around it is
brain. The bottom picture is the same child three
and a half months later, after he was shunted.
Note how much smaller the fluid spaces (dark
gray) are and the dramatic expansion of the brain
into the space created by removing the excess
CSF.
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Eavesdropping on the Brain cont

• 5. Single Photon Emission Computed Tomography
  (SPECT) - Measures blood flow and brain
  metabolism by monitoring photons emitted by
  iodine-labeled monoamine and diamine tracers
  carried in the blood to the brain.

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Guess what disorder these SPECT images reveal.
ADHD-Attention Deficit Hyperactivity Disorder
Normal
When methylphenidate (Ritalin) was administered
to ADHD children, its effect showed up as a
redistribution of blood flow in the brain,
methylphenidate appeared to increase the level of
function of the under-perfused regions at the
striatum, posterior periventricular region and to
a lesser extent the frontal lobes. This
normalization allowed the clutter of irrelevant
messages to be screened out and was seen as a
reduction in blood flow to the vision and hearing
areas. This filtering of irrelevant distraction
suppresses reflex responses and helps
concentration.
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Guess what disorder these SPECT images reveal.
Normal
Anxiety/panic Disorder
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Guess what disorder these SPECT images reveal.
Normal
Bipolar Disorder
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Guess what disorder these SPECT images reveal.
Normal
Depression
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