Sensory Modalities

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Sensory Modalities

• General Senses
• 1. Somatic (Exteroceptors)
• a. Touch
• b. Pressure
• c. Temperature
• d. Proprioception
• e. Pain
• 2. Visceral (Interoceptors)
• a. Pain
• b. Pressure

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Examples of sensory receptors and their
relationship with 1st order neurons
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Sensory Modalities

• Special Senses
• a. Smell or Olfaction
• b. Taste or Gustation
• c. Sight or Vision
• d. Sound or Auditory
• e. Balance or Equilibrium

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The Process of Sensations

• Stimulation of a sensory receptor
• Transduction of the stimulus
• Conversion of the stimulus into a
  graded potential
• Generation of an impulse
• Conversion of a graded potential into an
  action potential at a trigger zone and
  propagation to CNS
• 4. Integration of sensory input

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Classification of General Sensory Receptors
Type of Sense Receptor Type Stimulus
Touch Mechanoreceptor Compression
Pressure Mechanoreceptor Compression
Temperature Thermoreceptors Temperature
Proprioception Mechanoreceptor Compression
Pain Nociceptors Irritation
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Summary of Tactile Sensory Receptors
Receptor Sensations Adaptation
Meissner Corpuscles Touch, pressure, slow vibrations Rapid
Hair root plexuses Touch Rapid
Merkels disc Touch and pressure Slow
Ruffini corpuscles Stretching of skin Slow
Free nerve ending Itch/tickle Both
Pacinian Corpuscles Pressure, fast vibrations, tickling Rapid
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Summary of Sensory Receptors
Receptor Sensations Adaptation
Free nerve ending Temperature Rapid
Free nerve ending Pain Slow
Muscle spindles Muscle length Slow
Tendon organs Muscle tension Slow
Joint Kinesthetic receptors Joint position and movement Rapid
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Somatic Receptors of the Skin
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Classification of Special Sensory Receptors
Type of Sense Receptor Type Stimulus
Smell Chemoreceptor Binding of Molecules
Taste Chemoreceptor Binding of Molecules
Sight Photoreceptors Light
Sound Mechanoreceptor Sound waves
Balance Mechanoreceptor Movement of head
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Olfactory epithelium, Olfactory receptors, and
Olfactory Nerves
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Relationship of Gustatory receptors in Taste Buds
to tongue papillae