Chapter 48 Flashcards
What is the time span for slow pain?
begins only after 1 second or more and then increases slowly over many seconds and sometimes even minutes
What are the characteristic Sx of slow pain?
slow burning pain, aching pain, throbbing pain, nauseous pain, and chronic pain
What causes slow pain?
tissue destruction
What is the time span for fast pain?
pain felt within about 0.1 second after a pain stimulus is applied
What are the characteristic Sx of fast pain?
sharp pain, pricking pain, acute pain, and electric pain. not felt in most deeper tissues of the body
What causes fast pain?
when a needle is stuck into the skin, the skin is cut by a knife, when the skin is acutely burned, or when skin is subject to electric shock
Where are pain receptors?
Pain receptors (nociceotors) are free nerve endings and are widespread in superficial skin as well as periosteum, arterial walls, joint surfaces, and the falx and tentorium in cranial vault
What are the 3 different stimuli to cause pain?
mechanical, thermal, and chemical pain
Slow pain is caused by which stimuli?
Slow pain is elicited by all three mechanical, thermal and chemical pain
What types of substances cause chemical pain?
bradykin, serotonin, histamine, potassium ions, acids, acetylcholine, and proteolyic enzymes
Fast pain is caused by which stimuli?
just mechanical and thermal
true or false: there is a great deal of pain R adaptation
False
Why is failure of pain receptors to adapt important?
because it allows the person to be aware of the tissue damaging stimulus as long as it persists
What is the role of pain perception?
pain is a protective mechanism that tells the body that tissues are being damaged and causes the individual to react to remove the pain stimulus
What degree of temperature (C) causes tissue destruction and pain?
45
What is the most painful chemical in tissues?
bradykinin
Which 2 susbtances correlate to the intensity of pain felt in a local area of pain?
K ions or proteolytic enzymes
Tissue ischemia causes pain by the release of what substance?
lactic acid in the tissues formed from the cells use of anaerobic metabolism
Slow pain uses what type of fibers to sense pain?
C fibers
CV of C fibers?
0.5-2 m/sec
Fast pain uses what type of fibers to sense pain?
small type Aδ fibers
CV of Aδ fibers?
6-30 m/sec
Both fast and slow pain fibers enter the spinal cord from the dorsal spinal root and the pain fibers terminate on relay neurons where in the spinal cord?
dorsal horns
Neospinothalamic and paleospinothalmic are part of which pain tract?
Spinothalamic tract
What type of pain is neospinothalamic tract used for?
for fast pain and the fast type Aδ fibers transmit mainly mechanical and acute thermal pain