Pain Flashcards
What is pain?
An unpleasant sensory and emotional experience associated with actual or potential tissue damage
Why is pain important?
- Promotes avoidance of situations which may decrease biological fitness
- Promotes resting behaviour that either enhances recovery or modifies behaviour so that further injury or death becomes less likely
What type of receptors detect pain?
Nocioceptors
How is pain sensed throughout the skin?
Free nerve endings
How is pain felt from internal organs?
In the local area on the outside of the body
How is intense pressure, stretching, shrinking and pinching felt?
High threshold mechanoreceptors, due to depolorisation and calcium influx
Vanilloid receptors and temperature gated channels sense what types of pain?
Heats, acids and capsaicin
What do vanilloid receptors flux?
Sodium, leading to an action potential
Where are vanilloid receptors found?
In the free nerve endings
What is released following tissue damage?
ATP
What is the circuit that causes you to withdraw from a painful stimulus?
Spinal reflex reaction - neuron, spinal cord interneuron - efferent motor neuron
What is the name of the neurons that send messages about the initial pain to the brain (before you’ve realised the pain has occurred)?
Procioceptors
What are the features of procioceptors?
Large diameter and myelinated
Name the fibres that carry messages about the first pain, and localisation of the painful stimulus?
Delta fibres
What fibres provide the secondary pain that is the continuing dull ache?
C fibres