SENSE ORGANS

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SENSE ORGANS
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SENSE ORGANS

• Complex
• Contain receptors for special senses
• Convey information to the CNS via special nerves

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SENSE ORGANS

• Nose - olfaction - sense of smell
• Tongue - gustation - sense of taste
• Eyes -vision
• Ears - hearing equilibrium
• Skin - general senses

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NOSE

• Responds to chemical stimulation by producing a
  generator potential
• Epithelium of nasal cavity contains millions of
  bipolar, olfactory receptors
• Olfactory hairs - concerned with transduction
• Supporting cells - columnar epithelial cells -
  provide support, nourishment, insulation for
  receptors
• Basal stem cells - produce new receptors
• Olfactory glands - produce mucus

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Olfactory Mucosa and Bulb
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TONGUE

• Responds to chemical stimulation
• Gustatory receptors - located in taste buds of
  papillae
• Detects 4 major classes of stimuli - bitter,
  sour, salty, sweet

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Lingual Papillae

• Filiform and foliate papillae have no taste buds
  are important for detecting texture
• Tip of tongue is sensitive to sweetness
• Sides of tongue primarily detect saltiness
  sourness
• Vallate papillae (circumvallate) at rear of
  tongue detect bitterness

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Eye
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EYE

• Complex
• Associated with accessory structures
• Photoreceptors cells (rods cones) are located
  in the retina.

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Rods vs. Cones

• RODS CONES

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Ear
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EAR

• External (outer) ear - channels sound waves to
  middle ear
• Middle ear - directs sound waves to oval window
• Internal (inner) ear - contains mechanoreceptors
  (hair cells) for hearing equilibrium

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RECEPTORS OF EAR

• Organs of Corti - in cochlea concerned with
  hearing
• Cristae - in ampullae of semicircular canals
• Maculae - in utricle and saccule

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VESTIBULAR APPARATUS

• Concerned with equilibrium
• Composed of
• 3 semicircular ducts (canals)
• 1 saccule - anterior chamber
• 1 utricle - posterior chamber

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INNER EAR FLUIDS

• Perilymph - located in bony labyrinth
• Endolymph - located in membranous labyrinth

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EQUILIBRIUM

• Static - maintenance of position of the
  stationary body relative to gravity
• Dynamic - maintenance of position of the moving
  body