Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
72 Cards in this Set
- Front
- Back
|
Two types of pain
|
Fast pain and slow pain
|
|
|
How fast is “fast pain” felt?
|
0.1 second after a pain stimulus is applied
|
|
|
How fast is “slow pain” felt?
|
Slow pain begins only after 1 second or more and then increases slowly over many seconds and sometimes even minutes
|
|
|
What type of pain is associated with tissue destruction?
|
Slow pain
|
|
|
Pain Receptors are what kind of receptors?
|
Free Nerve Endings
|
|
|
Examples of internal tissues with pain receptors?
|
periosteum, the arterial walls, the joint surfaces, and the falx and tentorium in the cranial vault
|
|
|
Three Types of Stimuli Excite Pain Receptors
|
Mechanical, Thermal, and Chemical
|
|
|
Fast pain is elicited by what types of stimuli?
|
Mechanical or Thermal
|
|
|
Slow pain is elicited by what types of stimuli?
|
Mechanical, Thermal, and Chemical
|
|
|
Chemicals that excite the chemical type of pain?
|
bradykinin, serotonin, histamine, potassium ions, acids, acetylcholine, and proteolytic enzymes.
|
|
|
Chemicals that enhance the sensitivity of pain endings but do not directly excite them?
|
prostaglandins and substance P
|
|
|
Increase in sensitivity of the pain receptors is called?
|
hyperalgesia
|
|
|
Intensity of pain is closely correlated with?
|
the rate at which damage to the tissues is occurring (not with the total damage that has already occurred)
|
|
|
Chemical that seems to be more painful than others
|
bradykinin
|
|
|
What is ischemia?
|
blood flow to a tissue is blocked
|
|
|
suggested causes of pain during ischemia?
|
accumulation of large amounts of lactic acid in the tissues, formed as a consequence of anaerobic metabolism
|
|
|
Fast pain signals are transmitted in the peripheral nerves to the spinal cord by what fibers? and how fast?
|
small type A-delta fibers at velocities between 6 and 30 m/sec
|
|
|
Slow-chronic pain signals are transmitted in the peripheral nerves to the spinal cord by what fibers? and how fast?
|
type C fibers at velocities between 0.5 and 2 m/sec.
|
|
|
Fast pain signals are transmitted through what tract?
|
Neospinothalamic Tract
|
|
|
Fast type A-delta pain fibers terminate where?
|
terminate mainly in lamina I (lamina marginalis) of the dorsal horns
|
|
|
Second order neurons for fast pain begin and terminate where?
|
begin in Lamina I, cross immediately to the opposite side of the cord through the anterior commissure, and then turn upward, passing to the brain in the anterolateral columns.
Terminate in the ventrobasal complex of the thalamus (mostly). A few fibers of the neospinothalamic tract terminate in the reticular areas of the brain stem. A few fibers also terminate in the posterior nuclear group of the thalamus. |
|
|
Probably neurotransmitter of Fast pain?
|
Glutamate
|
|
|
Slow pain signals are transmitted through what tract?
|
Paleospinothalamic Pathway
|
|
|
Slow type C pain fibers terminate where?
|
Laminae II and III of the dorsal horns of the spinal cord, which together are called the substantia gelatinosa
|
|
|
Second order neurons for slow pain begin and terminate where?
|
Begin in Laminae II and III, got through one or more additional short fiber neurons within the dorsal horns themselves before entering mainly lamina V.
|
|
|
Probable Slow-Chronic Neurotransmitter of Type C Nerve Endings
|
Substance P
|
|
|
Paleospinothalamic Pathway ends where?
|
Only one tenth to one fourth of the fibers pass all the way to the thalamus. Instead, most terminate in one of three areas: (1) the reticular nuclei of the medulla, pons, and mesencephalon; (2) the tectal area of the mesencephalon deep to the superior and inferior colliculi; or (3) the periaqueductal gray region surrounding the aqueduct of Sylvius.
|
|
|
Localization of pain is easier for what type of pain?
|
Fast pain
|
|
|
Electrical stimulation in the reticular areas of the brain stem and in the intralaminar nuclei of the thalamus has what kind of an effect on the brain?
|
Arrousal effect. Almost impossible for a person to sleep when he or she is in severe pain.
|
|
|
Brain has the ability to suppress input of pain signals to the nervous system by activating a pain control system, called?
|
analgesia system
|
|
|
The analgesia system consists of three major components
|
1. The periaqueductal gray and periventricular areas and upper pons
2. the raphe magnus nucleus 3. a pain inhibitory complex located in the dorsal horns of the spinal cord. |
|
|
First component of the analgesia system is
|
The periaqueductal gray and periventricular areas of the mesencephalon and upper pons surround the aqueduct of Sylvius and portions of the third and fourth ventricles.
|
|
|
Second component of the analgesia system is
|
The raphe magnus nucleus, a thin midline nucleus located in the lower pons and upper medulla, and the nucleus reticularis paragigantocellularis, located laterally in the medulla.
|
|
|
Third component of the analgesia system is
|
A pain inhibitory complex located in the dorsal horns of the spinal cord. At this point, the analgesia signals can block the pain before it is relayed to the brain.
|
|
|
transmitter substances that are especially involved in the analgesia system
|
enkephalin and serotonin
|
|
|
enkephalin-secreting neurons that suppress pain signals are present where?
|
In both the cord and the brain stem.
|
|
|
Serotonergic neurons of the analgesia system begin / terminate where?
|
Begin in Raphe magnus nucleus and end in Enkephalin neurons
|
|
|
Mechanism of enkephalin?
|
cause both presynaptic and postsynaptic inhibition of incoming type C and type Ad pain fibers
|
|
|
Naturally produced opiate-like substances in the brain are all breakdown products of:
|
pro-opiomelanocortin, proenkephalin, and prodynorphin
|
|
|
Among the more important of these opiate-like substances are?
|
b-endorphin, met-enkephalin, leuenkephalin, and dynorphin
|
|
|
two enkephalins (met-enkephalin, leuenkephalin) found where?
|
in the brain stem and spinal cord
|
|
|
Where is B-endorphin found?
|
b-endorphin is present in both the hypothalamus and the pituitary gland.
|
|
|
Where is Dynorphin found?
|
Dynorphin is found mainly in the same areas as the enkephalins, but in much lower quantities.
|
|
|
pain in a part of the body that is fairly remote from the tissue causing the pain is called?
|
Referred pain
|
|
|
severe visceral pain is indicative of what kind of stimulation of nerve endings?
|
diffuse stimulation of pain nerve endings
|
|
|
Causes of true visceral pain
|
Ischemia, Chemical pain, spasm of a hollow viscus, over-distention of a hollow viscus
|
|
|
Which peritoneum are sensible to pain from a sharp knife cut?
|
parietal peritoneum, pleura, or pericardium (not visceral)
|
|
|
sensations from the abdomen and thorax are transmitted through which two pathways to the central nervous system?
|
true visceral pathway and the parietal pathway
|
|
|
True visceral pain is transmitted via?
|
pain sensory fibers within the autonomic nerve bundles, and the sensations are referred to surface areas of the body.
|
|
|
parietal sensations are conducted how?
|
directly into local spinal nerves from the parietal peritoneum, pleura, or peri- cardium, and these sensations are usually localized directly over the painful area.
|
|
|
heart’s visceral pain fibers pass upward along the sympathetic sensory nerves and enter the spinal cord where?
|
between segments C-3 and T-5
|
|
|
Where is visceral pain referred to on the surface of the body?
|
localizes it in the dermatomal segment from which the visceral organ originated in the embryo, not necessarily where the visceral organ now lies.
|
|
|
Possible causes of hyper-algesia are?
|
excessive sensitivity of the pain receptors themselves, which is called primary hyperalgesia
facilitation of sensory transmission, which is called secondary hyperalgesia. |
|
|
Sun-burned skin is an example of?
|
primary hyperalgesia
|
|
|
Lesions to the spinal cord is an example of?
|
secondary hyperalgesia
|
|
|
Herpes Zoster (Shingles)
|
Herpesvirus infects a dorsal root ganglion. This causes severe pain in the dermatomal segment sub- served by the ganglion, thus eliciting a segmental type of pain that circles halfway around the body.
|
|
|
Tic Douloureux
|
Lancinating pain over one side of the face in the sensory distribution area (or part of the area) of the fifth or ninth nerves; (aka trigeminal neuralgia or glossopharyngeal neuralgia).
|
|
|
Brown-Séquard Syndrome
|
Occurs if the spinal cord is transected on only one side.
All motor functions are blocked ipsilaterally in all segments below the level of the transection. Pain, heat, and cold are lost contralaterally in all dermatomes two to six segments below the level of the transection. kinesthetic and position sensations, vibration sensation, discrete localization, and two-point discrimination are lost ipsilaterally. |
|
|
Subtentorial pain stimuli vs. Above the tentorium is referred where?
|
Subtentorial pain stimuli cause “occipital headache” referred to the posterior part of the head. Above the tentorium initiates pain impulses in the cerebral portion of the fifth nerve and causes referred headache to the front half of the head.
|
|
|
Headache of the meninges is referred where?
|
entire brain
|
|
|
intense intracranial headache results from removal of as little as how much CSF fluid?
|
as little as 20 milliliters of fluid
|
|
|
Symptoms that begin before a migraine headache are called? begin when?
|
prodromal sensations begin 30 min - 1 hr before onset of headache
|
|
|
Prodromal symptoms include?
|
nausea, loss of vision in part of the field of vision, visual aura, and other types of sensory hallucinations
|
|
|
Headaches of Intracraneal vs. Extacraneal origin
|
Intracraneal Origin: Headache of Meninges, Migraine Headache, Alcoholic Headache, or Headache caused by constipation
Extracraneal Origin: Headache resulting from muscle spasm, Irritation of Nasal and Accessory Nasal Structures, or Eye Disorders |
|
|
Are there more warm spots or cold sensitive spots on the skin? How many times more?
|
3 to 10 times as many cold spots as warmth spots
|
|
|
How are warmth signals transmitted? (what type of fiber and how fast?)
|
warmth signals are transmitted mainly over type C nerve fibers at transmission velocities of only 0.4 to 2 m/sec
|
|
|
Cold-pain receptors are activate at what temps?
|
below 10-15 degrees
|
|
|
Cold receptors are activate at what temps? Peak at what temp?
|
10-15 degrees (peak at 25 degrees) die out slightly above 40 degrees
|
|
|
Warmth receptors are activated at what temp?
|
30 deg until 49 degrees
|
|
|
Heat-pain receptors are active at what temps?
|
above 45 degrees
|
|
|
Thermal senses respond markedly to?
|
changes in temperature
|
|
|
Mechanism of Stimulation of Thermal Receptors
|
changes in cell’s metabolic rates with change in temp
|
