Module 3:Brains Building Blocks AF

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Module 3Brains Building Blocks A-F

• Maria Recinos
• 1st period
• December 22, 2008

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Overview Human Brain

• Development of the Brain
• Genes-specific segment on the DNA that contains
  instructions for making proteins, the chemical
  building blocks from which all the parts of the
  brain and body are constructed

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Overview Human Brain

• Structure of the brain
• Glial Cells-cells in the nervous system that have
  at least 3 functions
• Neurons-cells that have specialized extensions
  for the reception and transmission of electrical
  signals

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Neuron
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Neurons Structure

• Cell body- relatively large, egg shaped structure
  that provides fuel, manufacture chemicals, and
  maintains the entire neuron in working order.
• Dendrites- branchlike extensions that arises from
  the cell body they receive signals from other
  neurons, muscles, or sense organs and pass these
  signals to the cell body.
• Axon- single threadlike structure that extends
  from, and carries signals from, the cell body to
  neighboring neurons, organs, or muscles.

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Neurons Structure

• Myelin sheath- looks like separate tubelike
  segments composed of fatty material that wraps
  around and insulates an axon. It prevents
  interference from electrical signals generated in
  adjacent axons.
• End bulbs or Terminal bulbs- looks like tiny
  bubbles that are located at the extreme ends of
  the axons branches. Each end bulb is like a
  miniature container that stores chemicals called
  neurotransmitters, which are used to communicate
  with neighboring cells.
• Synapse- infinitely small spaces that exist
  between an end bulb and its adjacent body organ,
  muscle, or cell body

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Reflex Responses

• Reflex- unlearned, involuntary reaction to some
  stimulus.
• Sensor- the skin of your fingers has specialized
  sensors, or receptors, that sensitive to hear
• Afferent neurons- neurons that carry info. from
  the spinal cord.

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Reflex Responses

• 3. Interneuron- relatively short neuron whose
  primary task is making connections between other
  neurons.
• 4. Efferent or Motor neurons- carry info. away
  from the spinal cord to produce responses in
  various muscle and organs throughout the body

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Overview

• Neurons structure cell body, dendrites, axon,
  myelin sheath, end bulbs, synapse.
• In the brain there are both glial cells and
  neurons.
• Transmitters- a chemical messenger that transmits
  info. between nerve and body organs

• Neurotransmitters-dozen different chemicals that
  are made by neurons and then used for
  communication between neurons during the
  performance of metal or physical activities.