1. PNS includes all nervous structures found where?
    • outside the CNS requiring three components:
    • 1. sensory receptors-pick up stimuli & send signals to CNS
    • 2. motor endings (axon synapse with effectors like muscles and glands)
    • 3. nerves and ganglia-neurons and cell bodies outside of CNS
    • NOTE: almost all nerves are mixed carrying both sensory and motor neurons
  2. Peripheral Sensory Receptors
    receptors are either dendritic ends of sensory neurons that monitor general sensory information over wide areas
  3. Exteroceptors
    receptors receiving stimulus from environment are sensitive to pressure, pain, smell, sight, and hearing (external stimulus & 4-5 senses

    free nerve endings, merkel discs, hair follicle receptors, meissner's corpuscle, pacinian corpuscle, ruffini endings
  4. Interoceptors
    receptors sensitive to body's internal changes, either visceral or chemical changes, taste, & tempherature (homeostasis internal signal to CNS)

    free nerve endings
  5. Proprioceptors
    receptors found within skeletal muscles, tendons, joints, & ligaments monitor amount of stretching sending input on movement (balance, coordination movement signal to CNS)

    free nerve endings, pacinian corpuscle, ruffini endings, muscle spindles, tendon organs, joint kinesthetic receptors
  6. What are the Classification by Location of sensory receptors?
    • Exteroceptors
    • Interoceptors
    • Proprioceptors
  7. Mechanoreceptors
    are stimulated by mechanical forces such as touch, pressure, ect. (mechanical forces)

    free nerve endings (pressure), merkel discs (light pressure), hair follicle receptors (hair deflection), meissner's corpuscle (light pressure, discriminative touch, vibration of low frequency), pacinian corpuscle (deep pressure, stretch, vibration of high frequency), ruffini corpuscle (deep pressure & stretch), muscle spindles (muscle stretch), tendon organs (tendon stretch), joint kinesthetic receptors
  8. Thermoreceptors
    stimulated by temperature changes (temperature)

    free nerve endings (heat & cold)
  9. Chemoreceptors
    respond to chemicals changes in blood, taste, or smell. (chemical changes)

    free nerve endings
  10. Photoreceptors
    respond to light such as those found in the eye. (light)
  11. Classification by stimulus detected
    • Mechanoreceptors
    • Thermoreceptors
    • Chemoreceptors
    • Photoreceptors
  12. Free dendritic endings
    sense pain & temperature changes along with some sense light touch (itch receptors are also free dendritic ends
  13. Encapsulated dendritic endings
    nerve endings wrapped in connected tissue serving as mechanoreceptors
  14. Meissner’s corpuscles
    detect light touch in the skin
  15. Krause’s End bulbs
    detect fine touch in mucus membranes
  16. Pacinian Corpuscles
    found in deep connective tissue (hypodermis) respond to vibration and briefly respond to deep pressure.
  17. Ruffini’s Corpuscles
    found in dermis respond to continuous pressure
  18. Proprioceptors
    found in muscle tissue, tendons, and ligaments monitoring stretch in locomotory organs
  19. Classification by structure
    • free dendritic endings
    • encapsulated dendritic endings
    • meissners corpuscle
    • krause's end bulb
    • pacinian corpuscle
    • ruffini's corpuscle
    • proprioceptors
  20. Peripheral Motor Endings
    axons synapsing with either muscle or glands to activate them

    • 1. Neuromuscular junction
    • 2. motor neuron
    • 3. acetylcholine (ACH)
    • 4. acetylcholinesterase (ACHS)
    • 5. motor unit
Card Set
PNS and receptors