Pain Flashcards
A study showed that short-term pain induced what in the brain in comparison to long-term chronic pain?
Short-term pain induces activation.
Long-term chronic pain induces strong and extended deactivation in the occipital, frontal and temporal lobes.
What does CIP stand for?
Congenital insensitivity to pain.
What are the two causes of CIP?
Mutation in a gene called SCNP9A which regulates the Nav1.7 pathway.
Overproduction of endorphins (body’s internal pain modulating system).
What is hereditary sensory and autonomic neuropathy (HSAN)?
The pain system degenerates over time, leading to loss of pain sensation.
What is pain asymbolia?
Individuals feel pain but are unable to recognise the unpleasant component of the painful stimulus, resulting in little or no defence reaction.
Damage or alterations to which brain areas give rise to pain asymbolia?
Cingulate region.
Frontal cortex.
Define nociception.
The neural processing of damaging substances or stimuli in response to tissue damage.
Name the five phases of nociceptive pain.
Transduction.
Conduction.
Transmission.
Perception of pain.
Modulation.
Why do we need pain?
Pain is our body’s learning system in response to dangerous activities or noxious and harmful substances.
How do thermoreceptors and nociceptors respond differently to a heat stimulus?
Activation of thermoreceptors increase in line with the temperature rise, then become saturated at around 40-42 degrees Celsius.
Nociceptors only become active at around 45 degrees Celsius.
Which nerve fibres drive heat responses below the pain threshold?
Large diameter non-nociceptive fibres.
Which nerves fibres drive pain signals in response to heat?
Smaller diameter less-myelinated fibres.
Define first pain.
Sharp pain.
Define second pain.
Dull ache associated with pain.
Which nerve fibres mediate first pain?
A-delta fibres.
Which nerve fibres mediate second pain?
C-fibres.
Nociceptive receptors are sensitive to which stimuli?
Thermal.
Chemical.
Mechanical.
Which five areas are nociceptive receptors found in?
Hairy skin.
Glabrous skin.
Muscles.
Joints.
Blood vessels.
Intestines.
Why are nociceptive receptors known as free nerve endings?
They lack specialised receptor cells.
How does non-discriminative/poorly localised touch arise?
Stimulation of free nerve endings that act as non-nociceptive, high-threshold mechanoreceptors.
What type of stimulus activates non-nociceptive, high-threshold mechanoreceptors?
Rough stimulus that doesn’t cause tissue damage, e.g. tapping, squeezing, rubbing and stretching of skin.
Describe the activity of non-nociceptive, high-threshold mechanoreceptors.
They have no background activity.
When stimulated, they respond for as long as the stimulus lasts.
What are the two types of non-nociceptive thermoreceptors?
Those activated by heat (35-45 degrees Celsius).
Those activated by cooling (17-35 degrees Celsius).