Nervous System

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Nervous System
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Main Function

• Main Function control and coordinate body
  functions and respond to stimuli (Think of
  stimuli as a signal that causes a reaction)

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The Nervous System

• Two main divisions
• Central Nervous System (CNS) includes the brain
  and spinal cord
• Peripheral Nervous System (PNS) contains nerves
  which carry info between the CNS and other organs

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Central Nervous System

• The brain receives signals (impulses) and sends
  signals back to the body
• The spinal cord connects the brain to the body.
  The spinal cord extends from the lower part of
  the brain down through spine. Along the way,
  various nerves branch out to the entire body

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CNS The Brain

• 3 major regions
• Cerebrum
• Cerebellum
• Brainstem

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CNS The Cerebrum

• Largest part of the brain
• Involved in voluntary activities, intelligence,
  and consciousness
• Divided into 4 lobes
• Frontal - personality
• Temporal - auditory

• Parietal - senses
• Occipital - visual area

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CNS Cerebellum Brainstem

• Cerebellum balance and coordination

• Brainstem includes the pons and medulla oblongata
• Involuntary functions
• heart rate, breathing

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PNS Peripheral Nervous System

• All nerves that are NOT part of the brain or
  spinal cord
• Two major divisions of the PNS
• Sensory division sends signals/impulses from
  sense organs (ears, nose, etc.) to the CNS
• Motor division send signals/impulses from the CNS
  to the muscles or glands

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Cells of the Nervous System

• Neurons the cells of the nervous system which
  pass information through the body

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Neuron Structure
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Disease of the brain

• Brain tumors - A brain tumor is an abnormal
  tissue growth in the brain.
• Epilepsy Seizures that disrupt brain activity.
• Encephalitis and Meningitis -These are infections
  of the brain and spinal cord that are usually
  caused by bacteria or viruses.

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Diagnostic Techniques

• MRI Magnetic Resonance Imaging uses radio waves
  and VERY powerful magnets to create images of the
  brain
• Used to image soft tissue, not bone or teeth

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MRI of the Brain