Balance

1
Balance the Cerebellum

• Balance, movements and sobriety testing

2
General Anatomy

• Outer Ear

3
Balance
4
Balance
5
The Labyrinth

• Hearing and balance use the same basic system of
  fluid spaces and bending hair cells
• How do sharks hear?

6
Otolith Semicircular Canals

• Otolith organs detect gravity and head tilt
• Semicircular Canals detect head rotation

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Otolith Organs

• Otolith organs detect gravity and head tilt

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Semicircular Canals

• Semicircular canals detect head rotation

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Macula

• Each otolith contains a sensory layer called the
  macula

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Macula

• Each otolith contains a sensory layer called the
  macula
• There is a bed of hair cells projecting into a
  gelatinous cap
• Otoliths are tiny crystals of calcium carbonate

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Macula

• Each hair cell has a special projecting hair
  element called the Kinocilium
• Bend the hair toward the Kinocillium and
  depolarize the neuron (excite) bend away and
  polarize (inhibit)

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• Macula the saccule macula is oriented vertically
  and the utricle macula are oriented horizontally.
  Since we have the same configuration on each side
  of the head the CNS gets complete info about head
  movements

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Macula Movements
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Semicircular Canals
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Semicircular Canals

• Detect head rotations

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Semicircular Canals

• Detect head rotations

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Semicircular Canals

• Detect head rotations

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Semicircular Canals

• Detect head rotations

19
CNS Connections

• Control movements of eyes, head and body
• Why do you vomit with motion sickness?

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CNS Connections

• Control movements of eyes, head and body
• Why do you vomit with motion sickness?