Ch 11 Pain

Question 1

Alpha fibres are

• myelinated/unmyelinated?
• larger/small in diameter?
• transmit pain signal quickly/slowly?
• pain is sharp/dull?

C fibres are:

• myelinated/unmyelinated?
• larger/small in diameter?
• transmit pain signal quickly/slowly?
• pain is sharp/dull?

Answer 1

Alpha fibres: myelinated, large, quick, sharp pain

C fibres: unmyelinated, smaller, slower, dull pain

Question 2

First phase of nociception is _______

-injured tissues release neurotransmitters such as:
_____________
-afferent nerve fibres terminate in ____ horn of spinal cord
-second set of neurotransmitters such as _______ carry pain across synaptic cleft to _____

Answer 2

Transduction

• injured tissues release substance P, histamine, prostaglandins, serotonin, bradykinin
• afferent nerve fibres terminate in dorsal horn
• second set of NT: substance P, glutamate, ATP carry pain to dorsal horn neurons

Question 3

Second phase of nociception is ________
-pain impulse moves from ____ to brain stem and thalamus

_____ receptors at synaptic cleft can block pain signalling

Answer 3

Transmission

pain impulse moves from spinal cord –> brain
-can be blocked by opioid receptors

Question 4

Third phase of nociception is _____:
-conscious awareness of pain
____ system = emotional response to pain
____ area = characterize pain

Answer 4

Perception

• Limbic system = emotional response
• somatosensory areas = characterize pain

Question 5

Fourth phase of nociception is _____

Descending pathways from brain stem –> spinal cord produce neurotransmitters to modulate pain
Neurotransmitters: _________

Answer 5

Modulation

Neurotransmitters: serotonin, norepinephrine, neurotensin, GABA, B-endorphins, enkaphalins, dynophins

Question 6

Nociceptive pain is caused by ______
-described as ______

Somatic pain is from _____
Visceral pain is _____

Answer 6

Nociceptive pain: tissue injury

• well localized
• aching/throbbing

Somatic pain: superficial (skin or sc) or deep (joints, muscle, tendons, bone)

Visceral pain: large interior organs (constant or intermittent, can be referred)

Question 7

Neuropathic pain: from lesion or disease affecting _______ nervous system
-described as ______

Answer 7

somatosensory nervous system

• burning/shooting/lancing
• often worse at night

Question 8

Chronic pain is pain present for ___ months or longer than time of expected healing

Answer 8

six

Question 9

Peripheral sensitization is ____ of pain threshold and ____ response at nociceptors’ peripheral end

Central sensitization is ____ in excitability of neurons in CNS

Answer 9

Peripheral sensitization: reduction in pain threshold, increased response of nociceptors

Central sensitization: increase in excitability

Question 10

Brief pain inventory: rates pain within the last ___ hours

Answer 10

24

Question 11

Neuropathic pain may ____ in severity at night or at times of _____ stimulation

Answer 11

may increase in severity at night or at times of decreased stimulation