neurobiology of pain Flashcards
(62 cards)
what is pain
An unpleasant sensory and emotional
experience associated with actual or
potential tissue damage or described
in terms of such damage.
what is pain classified by (4)
- underlying etiology
- anatomic location
- temporal nature
- intensity
what is included in underlying etiology
- nociceptive: tissue damage/injury ( incision post op fracture)
- inflammatory: infection and inflammation
- Neuropathic: nere damage/injury
what is included in anatomic location
somatic visceral
what is the duration of accute and chronic pain
acute < 3 month
chronic >= 3 months
what are the different classification of pain intensity
Mild:1-4
Moderate 5-7
Severe 8-10
what is nociceptive pain
- examples
- the result of direct tissue injury from a noxious stimulus.
- Examples include bone fracture, new surgical incision, and acute
burn injury
what is inflammatory pain
- examples
result of released inflammatory mediators that activates nociceptors
* Examples include appendicitis, meningitis, rheumatoid arthritis, inflammatory bowel disease
what is neuropathic pain
-examples
- the result of injury to nerves leading to an alteration in sensory transmission. It can be central or
peripheral in nature. - Examples include diabetic peripheral neuropathic pain, postherpetic neuralgia, chemotherapy induced pain, and ”sciatica
what is acute pain
- examples
- lasting less than three monthss and is a neurophysiological respone to noxious injury
- resolves with natural healing
-post-operative pain, fractured bones, appendicitis,
crush injury to finger
what is chronic pain
- examples
is defined as lasting more than 3 months(usually beyond the expected course of an acute
disease or after complete tissue healing).
* Examples include low back pain, most neuropathic pain syndromes,
and chronic pancreatitis.
what is acute on chronic pain
- examples
times of acute exacerbations
of a chronic painful syndrome or new acute pain in a person
suffering from a chronic condition.
- Examples include a sickle cell exacerbation in a patient with sickle
cell disease or an abscess in a patient with sickle cell disease.
how is pain intensitydetermined
- by pain assesment scores in combination with history and physical exam
- is subjective
what are pain scales used for
Pain Scales are used to assess and quantify the intensity of a patients pain.
Remember that each scale has its’ own scoring range and levels
for mild, moderate or severe pain intensity.
pain is part of ______ ______
normal sensation
what is the pain pathway
where the cell bodies of pain sensing neurons ( nociceptors)
- in the DRG
Aδ and C DRG neurons are ____
nociceotors
what type of neurons are Aδ and C nociceptors
They are Pseudounipolar neurons which has one extension
from its cell body and split into two branches.
what do the peripheral and central branches of Aδ and C DRG neurons do
Peripheral branches send free nerve endings to end organs
such as skin, muscle, joints, viscera, dura and blood vessels.
* Central branches form dorsal roots entering spinal cord dorsal
horn, synapse on Secondary sensory neurons.
what is the size of Aδ nociceptors, do they have mylintions?
what do they respond to
- Aδ nociceptors are small-medium neurons with thin myelinated
axons (fibers) - Aδ nociceptors respond to mechanical or mechanical/thermal
stimuli
what is the size of C nociceptors, are they mylinated?
- what do they respond to
- C nociceptors are small neurons with unmyelinated axons
- C nociceptors respond to mechanical, thermal and chemical stimuli
what dype of pain is the A and C noniceptors
- A: fast and sharp pain - high conduction velocity
- C: slow, aching pain - slow conduction velocity
both A and C nociceptors send ______ branches which eventually form _____ _____ _____ in end of organs such as ___ ____ ____
- peripheral branches
- free nerve endings
- skin, muscle , joints
