The Nervous System

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The Nervous System
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The Brain
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Function of the Nervous System

• 1. Regulates behavior
• 2. Maintains homeostasis
• 3. Regulates the other organ systems
• 4. Controls sensory and motor functions

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Central Nervous System Vs. Peripheral Nervous
System

• Central Nervous System
• Brain
• Spinal Cord
• Peripheral Nervous System
• Sensory neurons - running from stimulus receptors
  that inform the CNS of the stimuli
• Motor neurons - running from the CNS to the
  muscles and glands - called effectors - that take
  action.

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Major Parts of the Brain

• Cerebrum controls conscious activities,
  intelligence, memory, language, skeletal muscle
  movements, and senses
• Cerebellum controls balance, posture and
  coordination
• Brainstem - Medulla oblongata, pons and midbrain
  controls involuntary activities such as
  breathing and heart rate.

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Cerebrum
The brain is the only part of the body that does
not have pain receptors.
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Parts and Function of a Nerve Cell

• Cell Body (soma) - contains nucleus
• Dendrites - branch-like extensions that receive
  impulses and carry them to the cell body
• Axon - extension of the neuron carries impulses
  away from the cell body and towards other neurons
• AxonTerminals - connects to muscle, gland or
  another neuron, releases a chemical message
  (neurotransmitter)

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Neuron
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Diseases of the Nervous System

• Cerebral Palsy caused by abnormalities in parts
  of the brain that control muscle movements. The
  early signs of cerebral palsy usually appear
  before a child reaches 3 years of age.  Most
  common symptoms are a lack of muscle coordination
  when performing voluntary movements (ataxia)
  stiff or tight muscles and exaggerated reflexes
  (spasticity) walking with one foot or leg
  dragging walking on the toes, a crouched gait,
  or a scissored gait and muscle tone that is
  either too stiff or too floppy. Cerebral palsy
  cant be cured, but treatment will often improve
  a child's capabilities.

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• Epilepsy Epilepsy is a brain disorder in which
  clusters of nerve cells, or neurons, in the brain
  sometimes signal abnormally. In epilepsy, the
  normal pattern of neuronal activity becomes
  disturbed, causing strange sensations, emotions,
  and behavior or sometimes convulsions, muscle
  spasms, and loss of consciousness. Epilepsy is a
  disorder with many possible causes. Can be
  treated with various types of medication.

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• Parkinsons Disease affects nerve cells, or
  neurons, in a part of the brain that controls
  muscle movement. Neurons that make a chemical
  called dopamine die or do not work properly.
  Dopamine normally sends signals that help
  coordinate your movements. No one knows what
  damages these cells. Symptoms of Parkinson's
  disease may include Trembling of hands, arms,
  legs, jaw and face, stiffness of the arms, legs
  and trunk, slowness of movement, poor balance and
  coordination. As symptoms get worse, people with
  the disease may have trouble walking, talking or
  doing simple tasks. They may also have problems
  such as depression, sleep problems or trouble
  chewing, swallowing or speaking.