Neuron (Nerve Cell)

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Neuron (Nerve Cell)

• Cell Body
• Cytoplasm
• Nucleus
• Axon
• Carry messages away from the cell body to other
  neurons
• Dendrites
• Carry messages to the cell body

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Types of Neurons

• Receptor Cells
• Receives information from a stimulus
• For example - your finger gets hit by a hammer
• Sensory Neurons
• Carry the impulse to the spinal cord
• Travels the length of the arm to the spinal cord
• Interneurons
• Impulse is transmitted to the brain and the motor
  neurons via synapses
• Travels to the brain to register pain and out to
  the finger
• Motor neurons
• Sends the processed information back to finger
• Carries impulse to the effector cells in the
  fingers, hand and arm

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Nerve Impulses

• 120 meters per second speed at which impulses
  travel in the body.
• Synapse gap between two neurons (axon and
  dendrite)
• Impulse travels from one neuron to the next by
  sending chemicals across a gap to activate the
  next neuron.

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Reflex Arc

1. Hand touches open flame or hot burner
2. Impulse travels to spinal cord
3. Impulse sent to brain and back to hand.
4. Hand pulls back before pain is registered by brain

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Nervous System

• Two major divisions
• Central Nervous
• System (CNS)
• brain and spinal cord
• 2. Peripheral Nervous
• System
• motor and sensory neurons

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Central Nervous System
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Development of the brainConception - newborn
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Sagittal Section of Brain
cerebrum
Corpus callosum
cerebellum
Medulla oblongata
pons
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Inferior view of Brain
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Regions of the Brain

• Cerebrum - thought and reasoning
• Frontal - thinking, talking, remembering, moving
• Parietal - touching
• Occipital - seeing
• Temporal tasting, smelling, hearing
• Cerebellum coordination of muscular movements
• Medulla Oblongata involuntary responses
• Pons band of nerves linking the medulla and the
  cerebellum
• Olfactory sense of smell

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Spinal Cord
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Peripheral Nervous System

• Consist of the neurons (receptor and motor) which
  lead to and from the central nervous system
• Two divisions
• Sensory Somatic
• Autonomic