The Nervous System Neurons and the 5 senses

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The Nervous System Neurons and the 5 senses
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The Neurons

• Neurons are the cells that make up the nervous
  system
• They are long and stringy
• They carry electrical messages to and from your
  brain
• The basic functioning of the nervous system
  depends a lot on the neurons
• The brain has billions of neurons and they have
  many specialized jobs
• 1. sensory neurons
• 2. motor neurons

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Sensory Neurons

• They take information from the eyes, ears, nose,
  tongue, and skin and send it to the brain.
• Sense organs start to work when something
  stimulates special nerve cells called receptors.
• Once these receptors are stimulated, they send
  nerve impulses along sensory nerves to the brain.
  
• Your brain then tells you what this stimulus is.
• ARE THERE ANY FOOD ALERGIES?

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Come to Your Senses

• Ears Hearing
• Every sound we hear is the result of sounds waves
  entering our ears and causing our ear drums to
  vibrate.
• The vibrations are then are transferred along
  tiny bones of the middle ear and converted into
  nerve signals.
• The cortex then processes these signals telling
  us what we are hearing

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Activity 1 Mystery Noise

• 1. Receive handout
• 2. Close your eyes and see if you can guess what
  noise we are making
• 3. Record your answer on the handout

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Tongue Taste

• The tongue contains small groups of sensory
  cells called taste buds that react to chemicals
  in foods
• Taste buds react to sweet, sour, salty, and
  bitter
• Messages are sent from the taste buds to the
  areas in the cortex responsible for processing
  taste

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Activity 2 Jellybean Flavors

• 1. Receive handout
• 2. Different flavored jellybeans will be handed
  out
• 3. Record what flavor you think your jelly bean
  is on your handout

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Eyes Sight

• Sight probably tells us more about the world
  than all the other senses
• Light entering the eye forms an upside-down
  image on the retina
• The retina transforms the light into nerve
  signals fro the brain
• The brain turns the image right-side up and tells
  what we are seeing

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Activity 3 Target

• 1. Get into groups of two and get4 different
  color markers and one target
• 2. Place the target on the ground and one partner
  stands over it holding one color marker, point
  down over the target
• 3. Close one eye and move forward, backwards or
  side to side so that your aimed for the middle of
  the target, drop the marker when you think you
  are lined up.
• 4. Try three times with each eye and record on
  hand out.
• 5. Repeat for partner 2

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Nose Smell

• The cells in the lining of each nostril react to
  chemicals you breathe in and send messages along
  specific nerves to the brain
• Some research suggests that smells are very
  closely linked to our memories

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Activity 4 Expose Your Nose

• Join with 2 more groups to form groups of 6
• 4 stations are set up around the room, start
  your group at one and we will tell you when to
  rotate
• Sniff the bags at your station (Do not Peek!)
• Record answers on handout

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Skin Touch

• The skin contains more than 4 million sensory
  receptors - mostly in the fingers, tongue and
  lips
• They gather information related to touch,
  pressure, temperature, and pain then send it to
  the brain for processing and reaction

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Activity 5 Double Trouble

• Find a partner within your group of 6
• One partner get a bag and hold it out in front of
  your partner
• First pick out an object, then try to find its
  match relying only on your sense of touch
• Take turns