chapter 18

  1. Sensory receptor
    specialized cell or cell process that provides info abt conditions inside or outside body, characteristic of sensitivity and range
  2. General senses
    • Free nerve endings = simplest receptors
    • sensations arrive at somatosensory cortex
  3. Special senses (5) - smell, taste, balance, hearing, vision
    • structurally more complex
    • receptors - located in complex sense organs
    • sensations - arrive at specific area of cerebral cortex
  4. Phasic receptors (fast-adapting receptor)
    • inactive, provide info on intensity and rate of change of stimulus
    • touch,pressure and smell (central adaptation)
  5. Tonic receptors (slow-adapting receptor)
    • always active, little adaptation
    • Photoreceptors of eye, proprioceptors (body position)
  6. Nociceptors (general senses)
    • pain, tissue damage
    • free nerve ending - large receptive fields
    • 3 types - extremes of temperature; mechanical damage; dissolved chemicals
    • referred pain - visceral pain sensation perceived as originating in superficial regions inervated by same spinal nerve
  7. Thermoreceptors (general senses)
    • temperature change
    • free nerve endings
    • 4 times more cold receptors than warm
    • Phasic receptors - rate of change and intensity
  8. Mechanoreceptor (general sense)
    • contact or pressure
    • stimuli stretch, compress, twist, distort cell membranes
    • tactile - touch, pressure, vibration
    • lamillated corpuscle

    • baroreceptor - pressure change
    • blood vessels, stretch receptors, hollow organs

    • proprioceptor - position of joints and muscles
    • muscle spindle and golgi tendons
  9. Chemoreceptors (general sense)
    chemical composition of body fluids
  10. olfaction (smell)
    (special sense)
    Olfactory epithelium - cover inferior side of cribiform plate, conchae and septum

    • Organs:
    • olfactory receptor cells- modified neuron
    • basal cells - stem cells
    • thick mucus - olfactory glands = Bowman's glands

    • pathway:
    • receptors to O. nerve to O. bulbs to O. tract to O. cortex
  11. Gustation (taste)
    taste/gustatory receptors - taste buds resided on sides of papillae

    • 3 types of gustatory cells
    • taste hairs (microvilli)
    • taste pore
    • salivary juice

    Facial, Glossopharyngeal, vagus to thalamus to Gustatory cortex
  12. 4 primary taste sensation
    • sweet, salt, sour, bitter
    • umami - amino acids
    • water - water receptors

    threshold stimulation varies (survival value)

    olfactory organs role in taste perception
  13. Equilibrium and hearing
    External ear - external acoustic metas to tympanic membrane

    middle ear - 3 auditory ossicles

    Inner ear - 3 sensory organs for equilibrium and hearing
Author
krys
ID
75677
Card Set
chapter 18
Description
Chapter 18
Updated