Sensory Mechanism

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Sensory Mechanism

• Marie Cerná

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Five categories

• Mechanoreceptors - muscle spindle
• - hair cell in ear
• Pain receptors (nociceptors)
• Thermoreceptors
• Chemoreceptors - gustatory (taste)
• - olfactory (smell)
• Electromagnetic receptors
• - photoreceptors

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Structure of the eye
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Retina
Photoreceptors
Neurons
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Cells of Retina
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The effect of light on retinal
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Focusing in the eye
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Structure of the ear
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Structure of the ear
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A cross-sectional view of the cochlea with three
canals
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Mechanoreceptors
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Mechanism of hearing

• Vibrations, caused by sound waves, in
  the tympanic membrane are conducted via 3
  small bones to the oval window and create
  pressure waves in the cochlear fluid -
  perilymph.
• The waves pass through the vestibular canal to
  the apex of the cochlea, then back toward the
  base of the cochlea via the tympanic
  canal and end on the round window.

Semicircular canals
Cochlea
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As the basilar membrane vibrates, hair cells
repeatedly brush against the tectorial
membrane. This stimulus causes hair cells
to depolarize.
Perilymph
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Organs of balance
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A vestibule contains two chambersthe utricle
and saccule
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Gustatory chemoreceptors
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Olfactory chemoreceptors
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Nociceptors Thermoreceptors
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Literature

• Biology, eighth edition,
• Campbell, Reece
• Unit seven Animal Form and Function
• Chapter 50 Sensory and Motor Mechanisms
• Concept 50.1, 50.2, 50.3, 50.4
• Pages 1087 1105