Week 5: Pain

Question 1

Is pain a subjective or objective experience?

Answer 1

Subjective

Question 2

The PHYSIOLOGIC mechanisms involved in the pain phenomenon are termed ______.

Answer 2

nociception

Question 3

Free nerve endings are called what?

Answer 3

Nociceptors

Question 4

What are the four stages of physiology of pain? (Nociception can be divided into what four stages)

Answer 4

Transduction, transmission, perception, modulation

Question 5

Transduction

Answer 5

Process of converting painful stimuli to neuronal action potentials at the sensory receptors.
- Pain begins in periphery when free nerve endings called nociceptors are stimulated

Question 6

Transmission

Answer 6

Refers to the movement of action potentials along neurons that make their way from peripheral receptor to the spinal cord and then centrally to the brain.

Question 7

When does perception occur?

Answer 7

Occurs when the brain receives pain signals and interprets them as painful.

Question 8

Modulation

Answer 8

Complex mechanism whereby synaptic transmission of pain signals is altered

Question 9

Transduction: Where can nociceptors be found?

Answer 9

Skin, muscle, connective tissue, circulatory system, abdominal, pelvic and thoracic viscera.

Question 10

Transduction: What are some important chemical mediators of pain?

Answer 10

K+, H+, Lactate, histamine, serotonin, bradykinins, acetylcholine, substance P and prostaglandins.

Question 11

What are very common prostaglandin inhibitors? Describe briefly the role of prostaglandings in relation to pain threshold.

Answer 11

Aspirin and Non-steroidal anti-inflammatory drugs (NSAIDS).
- Prostaglandins formed when cells are damaged, then an enzyme breaks down multiple times to form prostaglandin, therefore the sensitization by prostaglandins lowers the pain threshold, causing pain when normally it would not.

Question 12

Transduction: What are the primary sensory fibers included in the transmission of nociceptive impulses?

Answer 12

• Aδ and C fibers

Question 13

Transduction: Describe Aδ fibers?

Answer 13

• Large, myelinated
• Thermal, mechanical stimuli
• Fast traveling
  -** Sharp, stinging, cutting, pinching, **
• Amount 10%

Question 14

Transduction: Describe C fibers?

Answer 14

• Unmyelinated
• Polymodal (mechanical, thermal, chemical)
• Slower travelling
• ** Dull, burning, aching ***

Question 15

Transuction: Afferent vs Efferent Neurons

Answer 15

Afferent neurons carries information from skin and other organs to CNS (brain, spinal cord)
Efferent carry motor information away from the central nervous system to the muscles and glands of the body.

Question 16

Transduction: Sensory afferent pain fibers enter the spinal cord by way of ______

Answer 16

Posterior nerve roots

Question 17

Transduction: Cells bodies of pain neuron are located where?

Answer 17

Dorsal root ganglion

Question 18

Pain perception can be described in what two terms?

Answer 18

Pain threshold and pain tolerance

Question 19

Pain threshold

Answer 19

Level of painful stimulation required to be perceived

Question 20

Pain tolerance

Answer 20

Degree of pain that one is willing to bear before seeking relief

Question 21

Describe some ways people express pain

Answer 21

Pacing, jaw clenching, facial grimacing, muscle guarding, crying moaning, groaning

Question 22

Describe the difference between physiologic and pathologic pain

Answer 22

Physiologic: touching Hot stove

Pathologic: characterized by an amplified response to normally innocuous stimuli, and an amplified response to acute pain. Pathological pain has long been described as the result of dysfunctional neuronal activity.

Question 23

T or F
Pain is a symptom of an underlying problem rather than a primary disorders

Answer 23

True

Question 24

When pain is classified in accordance to duration, it is either ______ or _______

Answer 24

Acute or chronic

Question 25

Signs and symptoms of someone with acute pain

Answer 25

- Elevated respiratory rate, heart rate and blood pressure, as well as pallor, sweating (diaphoresis) and nausea

Question 26

How do persons experiencing acute pain express it? *

Answer 26

Pacing, grimacing, crying, moaning * risk of becoming dependent on pain meds is minimal.

Question 27

What is the most common cause of acute pain?

Answer 27

Headache

Question 28

Chronic pain can be considered chronic if it lasts for several months (around 6). What are two probable mechanisms for chronic pain?

Answer 28

Peripheral sensitization and central sensitization

Question 29

Peripheral sensitization

Answer 29

Reduction in pain threshold and an amplification in responsiveness of nociceptors when primary sensory neurons are exposed to inflammatory mediators

Question 30

Central sensitization (Give an example)

Answer 30

- Increased sense of pain with things that should not be causing you so much pain. - When neurons in dorsal horn are affected by central senisitzation they develop increased spontaneous activity and reduction in threshold - Fibromyalgia is the best example. Body becomes sensitized due to psychological factors such as stress, sleep problems and fatigue.

Question 31

T or F Chronic pain symptoms are often more psychological

Answer 31

True

Question 32

What is fibromyalgia?

Answer 32

- Often triggered by psychological stress - Chronic pain syndrome, where women are more affected then men with chronic widespread affecting all four extremeties, sleep disturbances and fatigue. - Relates to individuals with excessive trauma and endocrine disorders

Question 33

Describe hyperalgesia and allodynia

Answer 33

Hyperalgesia: Extreme sensitivity to pain Allodynia: Pain to stimulus that usually doesnt cause pain

Question 34

Describe 3 other types of chronic pain?

Answer 34

neuropathic, ischemic and reffered pain

Question 35

Which of the following can result in nerve injury? (SATA) 1. Surgery 2. Tumour growth 3. Metastasis 4. Radiation therapy 5. Chemotherapy 6. Elevated blood glucose 7. Viral infections

Answer 35

ALL

Question 36

Clinical manifestations of neuropathic pain

Answer 36

- Allodynia - Hyperalgesia - Atrophy of affected extremity - Coldness in affected area - Dystrophic changes - Hair loss - Shiny appearance of skin

Question 37

If you have hair loss, shiny appearence of skin and coldness in an affected area, what type of pain are you most likely to have? (reffered, neuropathic, ishemic)

Answer 37

Neuropathic

Question 38

Pain resulting from sudden or profound loss of blood flow to tissue main result in ____

Answer 38

Ischemic pain

Question 39

Ischemic pain is described as _____

Answer 39

Aching, burning, or prickling (paresthesia)

Question 40

If you have ischemic pain of cardiac origin, where will pain originate and radiate to?

Answer 40

Origin is visceral and radiates to arm or jaw

Question 41

Symptoms of ischemic pain

Answer 41

Deep, aching, diffuse and pressing

Question 42

____ ischemia is usually associated with thrombus or embolus. (Chronic or acute)

Answer 42

Acute. - Can be dissolved or removed

Question 43

Referred pain may be perceived at some distance from the area of tissue injury, but generally felt _____ a. with slightly less intensity b. on the same side of the body c. within the same dermatome d. within 10 to 15 cm area

Answer 43

C. Within the same dermatomee

Question 44

Substance P

Answer 44

A neurotransmitter and a modulator of pain perception by altering cellular signaling pathways

Question 44

What are physiological responses to pain?

Answer 44

- Increase gastric secretions - Decrease gastrointestinal motility - Increase circulating blood glucose - Hypomotility of bladder and ureters - Blood shifts from superficial vessels to striated muscles, heart, lungs, brain - Bronchioles dilate to increase oxygenation