Pain study guide (highlighted) Flashcards
(117 cards)
Epicritic sensations are what kind of sensations?
light touch, pressure, proprioception and temperature discrimination
Epicritic sensations are characterized by?
conducted by?
characterized by low threshold receptors and are generally conducted by large myelinated nerve fibers
Protopathic sensations (pain) are detected by what kind of receptors? conducted by what type of nerve fibers?
detected by high-threshold receptors and conducted by smaller, myelinated a-delta and unmyelinated C nerve fibers.
Nociception’s do they all produce pain?
Yes, all nociception produces pain, but not all pain results from nociception.
Describe Chronic pain?
Chronic pain is pain that persists beyond the usual course of an acute disease or after a reasonable time for healing to occur. This healing can vary from 1 to 6 months. Chronic pain may be nociceptive, neuropathic or mixed. A distinguishing factor of chronic pain is that psychological mechanisms or environmental factors frequently play a major role.
2nd order neurons:
The spinothalamic tract?
Classically considered the major pain pathway. It lies anterolaterally in the white matter of the spinal cord. It is an ascending tract
Spino-mesencephalic tract?
may be important in activating anti-nociceptive, descending pathways because it has some projections to the peri-aqueductal gray
Third order neurons?
Located in the thalamus & send fibers to somatosensory areas I & II in the postcentral gyrus of the parietal cortex & the superior wall of the sylvian fissure, respectively.
What is unique about the cornea and tooth pulp?
they are almost exclusively innervated by nociceptive Aẟ & C fibers.
generally insensitive tissues that mostly contain silent nociceptors.
Visceral organs
Most other organs such as the intestines are innervated by what kind of nociceptors?
polymodal
polymodal nociceptors respond to what kind of pain stimulation? (think intestines)
smooth muscle spasm, ischemia, and inflammation
polymodal nociceptors such as in the intestines, these receptors generally do not respond to what kind of stimulation?
cutting, burning, or crushing that occurs during surgery.
The brain lacks nociceptors totally, however what covering of the brain does contain nociceptors?
meningeal covering
somatic nociceptors and visceral nociceptors both are free nerve endings of primary afferent neurons whose cell bodies lie in the?
dorsal horn
Main excitatory NT is?
Glutamate
exaggerated response to pain at the site of injury would be described as?
Primary hyperalgesia
Describe 2ndary hyperlgesia?
increased pain response evoked by stimuli outside the area of injury.
s/s of secondary hyperlgesia?
red flushing, local tissue edema, and sensitization to noxious stimuli. Does not have skin denervation.
Acute pain is typically associated with?
neuroendocrine stress response that is proportional to
pain intensity.
CV effects of acute pain would be?
Cardiovascular effects are often prominent and include hypertension, tachycardia, enhanced myocardial irritability, and increased systemic vascular resistance.
Cardiac output increases in most normal patients but may decrease in patients with compromised ventricular function. Because of the increase in myocardial oxygen demand, pain can worsen or precipitate myocardial ischemia.
Does acute pain increase or decrease total body oxygen consumption and carbon dioxide production?
increases both, leading to an increase in min. ventilation.
If you have acute pain and an abdominal or throacic incision what typically occurs?
compramised pulmonary function do to guarding or splinting of the are (less deep breaths are going to take place)
decreased movement of the chest wall due to acute pain in this area will lead to?
reduced tidal volume and FRC, promoting atelectasis, intrapulmonary shunting, hypoxemia, and, less commonly, hypoventilation.