Human Interface Sensory Input

Peripheral Receptors According to Site

  1. Exteroceptive (touch, pressure, pain, warmth, cold)
    Sensation detected on the surface of the body.
  2. Proprioceptive (stretch, tension or movement)
    Sensory information of joint position, muscle contraction, and muscle tension.
  3. Visceral (stretch or distention)
    Sensory information from internal organs.
  4. Deep Sensory (deep pressure)
    Sensory information from tissue pressure receptors, bone information and some pain receptors.


Peripheral Receptors According to Function

  1. Nociceptors
  2. Thermoreceptors
    Cold receptors, heat receptors.
  3. Chemoreceptors
    Oxygen and Carbon Dioxide receptors in the aortic and carotid bodies.


Motor and Sensory Fiber Classification

  1. Group A (myelinated)
    1. a: 13-22 mm diameter; 80-120 m/s
      1. Ia Motor innervates extrafusal fibers. Sensory primary afferants of muscle spindles.
      2. Ib Sensory Only: Golgi tendon organs, touch and pressure
    2. b: 6-13 mm diameter; 35-75 m/s
      aka Type II sensory fiber. Motor: Motoneuron for both extrafusal and intrafusal (muscle spindle) fibers. Sensory: Secondary afferents of muscle spindles, touch/pressure receptors, and Pacinian corpuscles.
    3. g: 8 mm diameter; 15-30 m/s
      Motor Only for intrafusal fibers.
    4. d: 1-5 mm diameter; 5-35 m/s
      aka Type III sensory fiber. Sensory Only termperature, pain, pressure, touch.
  2. Group B (myelinated)
    3 mm diameter; 14 m/s. Motor Only preganglionic autonomic fibers.
  3. Group C (unmyelinated, slow-conducting)
    .2-1.5 mm diameter; .5-2.0 m/s
    aka Sensory Group IV. Sensory: Pain and temperature. Motor: Post-ganglionic autonomic fibers.