Pain Flashcards
3 types of pain?
nociceptive
inflammatory
pathological
which of the 3 types of pain is adaptive?
nociceptive
inflammatory
when would pain be classed as pathological?
when it outlives its biological purpose and thus becomes debilitating
which type of pain occurs immediately after damage?
nociceptive
what are nociceptors
peripheral primary sensory afferent neurones
what activates nociceptors
intense stimuli eg thermal, mechanical, chemical
how does the stimuli cause neurotransmitters to be released?
stimuli acts on peripheral terminal of nociceptor -> depolarisation -> AP -> central terminal in CNS -> release of NTs
are nociceptors first or second order neurons
first
what type of neurons are neurotransmitters trying to attract
second order
which type of pain is exhibited in the withdrawal reflex
nociceptive
how is inflammatory pain different from nociceptive in terms of the feeling of pain?
something that wouldn’t hurt before hurts now - pain hypersensitivity and allodynia
what is allodynia
innocuous stimuli now illicit pain
how does inflammatory help to repair damage?
pain stops you touching area
discourages movement
does inflammatory pain involve the autonomic nervous system?
no
does inflammatory pain involve spontaneous pain
yes
what is pathological pain
pain that has no protective function; there due to abnormal nervous system
name 2 types of pain caused as a result of a dysfunctional nervous system
neuropathic
dysfunctional
what does neuropathic pain feel like?
spontaneous pain
pain hypersensitivity
maladaptive
what does dysfunctional pain feel like
no pain when there should be
what causes neuropathic pain?
peripheral nerve
lesion to nerve
what causes dysfunctional pain?
abnormal central processing
normal peripheral nerves
what happens in patients with congenital insensitivity to pain?
loss of function mutations halt production of an Na channel that is important in nociceptive neurons
lack of nociceptor function
give examples of loss of function mutations
missense
deletions
name the 2 types of nociceptor?
A delta fibres
C fibres
which of the 2 nociceptor types is unmyelinated?
C fibres
which nociceptor type mediates slow pain
C fibres
what type of nociceptor produces stabbing, pricking sensations
Alpha delta fibres
what type of nociceptor produces burning , throbbing, cramping, aching sensations
C fibres
what nociceptor type is activated by touching an object over 53oc
alpha delta type 1
which nociceptor types are activated by touching and object 43oc and under
c-polymodal
alpha delta
through which areas of the neuron are chemical substances released?
central and peripheral terminals
what systemic effects does substance P have on body?
vasodilation
histamine release
sensitises nociceptors
helps form prostaglandins and bradykinin
does glutamate produce a fast or slow epsp?
fast
where are primary afferent cell bodies located?
dorsal root ganglia
