TRANSDUCTION Flashcards
name this definition for sensory receptors
mechanical, thermal, chemical, visual, auditory
modality specific
name this definition for sensory receptors
determined by its strength (must be an adequate stimulus)
intensity
name this definition for sensory receptors
the difference in magnitude necessary to discriminate a reference stimuli from a second stimulus increased above the intensity of the reference stimulus. Localizes where the stimulus is coming from
detectibility
name this definition for sensory receptors
diminishes with time
duration of a sensation
name this definition for sensory receptors
conversion and amplification of sensory stimulus energy into an electrical signal
transduction
free nerve endings, merkels disks, Ruffini’s end bulbs, krauses endbulbs (warmth and cold)
slow adapting
meissner’s and pacinian corpuscles, hair follicle which respond best to changing stimuli
rapid adapting
what are the functional types of receptors?
mechanoreceptors, thermoreceptors, electromagnetic, chemoreceptors, nociceptors
what are the non encapsulated anatomical type receptors?
free nerve endings
merkels discs
hair follicle receptors
what are the encapsulated anatomical type receptors?
meissner’s corpuscles
pacinian corpuscles
ruffini’s corpuscles
this type of anatomical type receptor detects warmth nd cold (all skin)
krauses end bulbs
this neuromuscular receptor responds to muscle stretch
muscle spindle
this neuromuscular receptor responds to tendon stretch?
Golgi tendon organ
this neuromuscular receptor responds to stretch of skin
ruffini corpuscle
an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage.
in general terms, we can distinguish two dimensions or components of pain, sensory discriminative and affective emotional
pain
this is the process by which information about a noxious stimulus is conveyed to the brain?
nociception
what are the different types of pain?
nociceptive
neuropathic
inflammatory
name this type of pain?
represents the normal response to noxious insult or injury of tissues such as skin, muscles, visceral organs, joints and tendons
nociceptive
name this type of pain?
the pain initiated or caused by a primary lesion or disease in the somatosensory nervous system
neuropathic
a result of the activation and sensitization of the nociceptive pain pathway by a variety of mediators released at a site of tissue inflammation
inflammatory
how is pain intensity categorized?
mild, moderate severe
what is pain duration?
time course
what is pain less than 3 to 6 months in duration
acute pain
what is pain lasting for more than 3-6 months or persisting beyond the course of an acute disease or after tissue healing is complete
chronic pain
acute pain flare superimposed on the underlying chronic pain
acute on chronic pain
what are the afferent fibers for pain? what do they release?
thinly myelinated, faster conducting A delta fibers (first pain)
unmyelinated slowly conducting C fibers (second pain)
glutamate or substance P
how are pain and temperature sensations from the periphery transmitted? what are the components and what is formed as a result of this?
to higher centers via ascending sensory tracts
GSA and GVA forming the anterolateral system
what comprises the anterolateral system?
spinothalamic tract spinoreticular tract spinotectal tract spinomesencepalic tract spinobulbar tract spinohypothalamic tract
what are the primary ascending pathways for pain?
spinothalamic tracts
- lateral spinothalamic tract
- anterior spinothalamic tract
dorsolateral tract of Lissauer
name this theory:
C and Adelta afferents of there 1st order nociceptive neurons, that terminate in the substantia gelatinosa relay nociceptive impulses by inhibiting SG interneurons?
Gate control threory via modulation of nociception
these types of fibers stimulate inhibitory interneurons and the 2nd order neurons of the spinothalamic tract
Aa and Ab (Ia and Ib) fibers (large touch pressure, proprioceptive 1st order neurons) that stimulate inhibitory interneurons and the 2nd order neurons of the spinothalamic tract
these interneurons establish presynaptic inhibitory synapses with the C, Adelta, Aalpha, or Abeta fibers preventing the impulses from being transmitted to the 2nd order neuron
what are the descending pathways that modulate pain?
periaqueductal gray
nucleus raphe magnus (serotonergic)
locus ceruleus (noradrenergic)
what are the theories of referred pain?
convergence projection theory
concept of referred pain
GVA and GSA afferent fibers terminate at the same spinal cord level, and converge and synapse on the same interneurons and or second order projection neurons
convergence projection theory
suggests that the GVA 1st order neurons continuously stimulate 2nd order projection neurons which transmit nociceptive sensory input from somatic structures via the spin-reticular fibers to the reticular formation, thalamus, and hypothalamus. Input transmitted to the somatosensory cortex which receives somatic sensory input from somatic structures and this misinterprets the source of origin of the nociceptive input
concept of referred pain
when non-nociceptive stimuli are perceived as being painful
allodynia
implies increased sensitivity in the area of the damaged tissue
primary hyperalgesia
increased sensitivity in tissues adjacent tot eh actual site of tissue damage. Due to release of certain substances from the damaged tissue which make the receptors more excitable
secondary hyperalgesia
when are secondary hyperalgesic agents released?
by mast cells when nearby cells are injured which are neuropeptides
what are the secondary hyperalgesic agents?
bradykinin prostaglandins substance P Calcitonin gene histamine and serotonin
name this secondary hyperalgesic agent
from the proteolytic breakdown of extracellular kinogens. also a potent vasodilator
bradykinin
name this secondary hyperalgesic agent
from the enzymatic breakdown of lipid membranes
prostaglandins
name this secondary hyperalgesic agent
added NTs in nociceptors generated by extreme nociceptor activity
leads to vasodilation
PG, histmine and cytokine release
stimulates angiogenesis
substance P and calcitonin gene
name this secondary hyperalgesic agent
released by mast cells through the stimulation of substance P leading to increased sensitization and vasodilation
histamine and serotonin
this is found in spicy foods and seasonings; causing an increase in the release of substance P. In high concentrations used as a topical rub
capsaicin
what is another ascending pathway we talked about in which the these sensory impulses for visceral pains caused by ischemia leads to smooth muscle spasm or distension.
viscerosensory tract
this ascending tract enters the spinal cord through the anterior roots
viscerosensory tract
