[10] Pain: Pathophysiology and Management Flashcards
What are the body’s responses to pain?
Increased blood pressure, heart rate, pupil size, plasma cortisol levels and local muscle contraction (e.g. limb flexion or abdominal wall rigidity)
What are the components of a peripheral nerve?
- Primary sensory afferents
- Motor neurons
- Sympathetic postganglionic neurons
Where are the cell bodies of the primary sensory afferent neurons?
Dorsal root ganglion in vertebral foramina
How are primary afferent neurons classified?
- Diameter
- Degree of myelination
- Conduction velocity
What are the primary afferent nociceptors?
Alpha-delta and C fibers
Which fiber is responsible for detecting light touch?
Alpha-beta fiber
With intense, repeated or prolonged stimulation of inflamed tissue, what happens to frequency and threshold of firing of nociceptors?
Increased frequency and decreased threshold of firing
TRUE OR FALSE: All sympathetic postganglionic fibers are unmyelinated.
True
What are the two types of sensitization?
- Peripheral
2. Central
Central and peripheral sensitization involve what structures?
Central - dorsal horn of spinal cord
Peripheral - nerve terminal
What do you call an increased pain response to the same stimulus?
Hyperalgesia
What do you call exquisite sensitivity to normally innocuous stimuli?
Allodynia
What is the neuroeffector function of primary afferent nociceptor activation?
Release of substance P
What are the roles of substance P?
- Vasodilator
- Inflammatory mediator
- Leukocyte chemoattractant
What type of edema does Substance P cause?
Neurogenic edema
