Anatomy and Physiology of Pain Flashcards
What are the four physiological mechanisms of pain?
Transduction
Transmission
Perception
Modulation
Define pain
Unpleasant sensation and emotional experience associated with actual or potential tissue damage, or described in terms of such damage
What is nociceptive pain?
Normal, acute pain resulting from nociceptor activity
Which is the fastest nociceptor sensory neurone?
Ad
Which is the slowest nociceptor fibre?
C
Which is the second fastest nociceptor fibre?
Ab
What are in the membrane of nociceptors which allow responses to tissue damaging stimuli
receptor proteins
Which receptor detects pH changes in skeletal and cardiac muscle relating to ischaemia?
ASIC3
Why is there sometimes lack of pain fibres?
Shortened life span
Which nociceptors produce sharp, fast pain?
Ad (+ some Ab)
Where are nociceptors present?
Thermal + Mechanical
Provides precise location
Where do Ad fibres synapse?
laminae I and V
What type of pain do C fibres produce?
slow, burning
What are the two types of C fibres?
Peptidergic fibres
Peptide poor fibres
What do peptidergic fibres do?
Release peptides to produce inflammatory responses + healing
What do peptide poor fibres do?
Have distinct receptors which provides mechanical nociception
Where do C fibres synapse?
laminae I and II
Where do C fibres also innervate through interneurons?
lamina V
What does the spinothalamic tract pathway start + finish?
Sensory pathway from skin to thalamus
Where is information from Ventral Posterolateral (VPL) of the thalamus relayed to?
somatosensory cortex of brain?
Where does spinothalamic tract decussate at?
Level of spinal cord
What does the lateral spinothalamic tract modulate?
Pain + Temperature
Where does the lateral spinothalamic tract end?
Different sites of the brainstem
What are the primary afferents of lateral spinothalamic tract?
C fibres and some Ad fibres
Where are projection neurones found in lateral spinothalamic tract?
laminae I
What does the lateral tract innervate?
more posterior and medial parts of the thalamus; MDvc, POm and VMpo