To understand the ‘anatomy of pain’ ​

Question 1

What is the definition of pain according to the International Association for the Study of Pain (IASP, 2012)?

Answer 1

An unpleasant, subjective sensory and emotional experience associated with actual or potential tissue damage.

Question 2

What are the main 4 purposes of pain?

Answer 2

• Alert System: Warns of injury or potential injury-causing stimulus
• Protective Mechanism: Information about the environment or tissue injury
• Emotional Impact: Can cause irritability, anxiety, and behavioral changes
• Psychological Aspect: Pain can exist without physical injury.

Question 3

What are the two main types of pain?

Answer 3

• Nociceptive Pain
• Neuropathic Pain

Question 4

What causes nociceptive pain?

Answer 4

Activation of pain receptors (nociceptors) by noxious stimuli.

Question 5

What is neuropathic pain?

Answer 5

Pain caused by damage to nerves, leading to chronic (long-term) pain.

Question 6

What are nociceptors?

Answer 6

Free nerve endings present everywhere except the brain, activated by thermal, mechanical, or chemical noxious stimuli.

Question 7

What are the main neurotransmitters involved in nociceptive pain?

Answer 7

• Glutamate
• Substance P

Question 8

What are the two types of fibers involved in nociceptive pain transmission?

Answer 8

• A-Delta Fibers: Detect sharp, localized pain
• C-Fibers: Detect dull, aching pain

Question 9

What is hyperalgesia?

Answer 9

Increased pain sensitivity after an injury.

Question 10

What is allodynia?

Answer 10

Pain from non-painful stimuli.

Question 11

What are the four stages of nociceptive pain?

Answer 11

• Nociception
• Transmission
• Perception
• Modulation

Question 12

What happens during the nociception stage of pain?

Answer 12

Nociceptors detect noxious stimuli, and signals are transmitted via spinal nerves to the dorsal horn of the spinal cord.

Question 13

What is the role of the thalamus in pain perception?

Answer 13

Processes pain information and relays it to higher brain centers.

Question 14

True or False: Chronic pain is temporary and resolves with healing.

Answer 14

False

Question 15

What is the difference between acute and chronic pain?

Answer 15

• Acute Pain: Temporary, resolves with healing
• Chronic Pain: Persistent, independent of initial cause

Question 16

What is phantom limb pain?

Answer 16

Perceived pain in an amputated limb experienced by nearly all amputees.

Question 17

What are some pharmacological approaches to pain management?

Answer 17

• Mild pain: Paracetamol, NSAIDs
• Moderate pain: Weak opioids (e.g., codeine)
• Severe pain: Strong opioids (e.g., morphine)

Question 18

Fill in the blank: The _______ regulates pain signals in the dorsal horn according to the Gate Control Theory of Pain.

Answer 18

nerve gate

Question 19

What is the role of prostaglandins in pain sensitization?

Answer 19

Prostaglandins lower the activation threshold of nerve endings, increasing sensitivity to stimuli.

Question 20

What are some non-pharmacological approaches to pain management?

Answer 20

• Cognitive Behavioral Therapy (CBT)
• Physiotherapy & Exercise
• Transcutaneous Electrical Nerve Stimulation (TENS)
• Mindfulness & Meditation
• Acupuncture

Question 21

What is neuroplasticity in the context of chronic pain?

Answer 21

The brain rewires itself, potentially leading to persistent pain.

Question 22

What can prolonged muscular contractions lead to?

Answer 22

Ischemia and pain.

Question 23

What is the role of A-Beta fibers in pain modulation?

Answer 23

Inhibit nociceptive signals in the dorsal horn.

Question 24

What is the impact of psychological factors on pain perception?

Answer 24

They can influence pain perception, creating a pain-anxiety cycle.

Question 25

What are common symptoms of neuropathic pain?

Answer 25

* Sharp pain * Burning pain * Tingling pain * Paraesthesia * Hypoesthesia (reduced sensation)

Question 26

What is the WHO Analgesic Ladder used for?

Answer 26

Guides pain management strategies.

Question 27

What can reduced prostaglandins due to NSAIDs lead to in the stomach?

Answer 27

Gastric ulcers and increased risk of stomach bleeding.

Question 28

What is the effect of NSAIDs on kidney function?

Answer 28

Can impair kidney function, leading to fluid retention and high blood pressure.

Question 29

Where are nociceptors found, and what activates them?

Answer 29

Found in skin, joints, muscles, and internal organs; activated by thermal, mechanical, or chemical noxious stimuli.

Question 30

What neurotransmitters are involved in nociceptive signalling?

Answer 30

Glutamate and substance P.

Question 31

What are the two types of nociceptive fibers?

Answer 31

A-Delta Fibers: Myelinated, fast, detect sharp, localized pain. C-Fibers: Unmyelinated, slow, detect dull, aching pain.

Question 32

How do prostaglandins contribute to pain sensitivity?

Answer 32

They lower the activation threshold of nociceptors, leading to hyperalgesia (heightened pain response) and allodynia (pain from non-painful stimuli).

Question 33

What happens in the transmission stage?

Answer 33

Pain signals travel via A-Delta fibers (sharp pain) and C-Fibers (dull pain). Neurotransmitters glutamate and substance P relay signals to spinal neurons. Signals are sent to the thalamus via the spinothalamic tract.

Question 34

What happens in the perception stage?

Answer 34

The thalamus processes pain and sends signals to the cortex and limbic system for sensory and emotional processing.

Question 35

What happens in the modulation stage?

Answer 35

Gate Control Theory: A-Beta fibers inhibit pain signals. Brainstem pathways release endorphins, serotonin, and noradrenaline to reduce pain perception.

Question 36

What causes neuropathic pain?

Answer 36

Damage to nerves, brain, or spinal cord.

Question 37

What are examples of conditions causing peripheral and central nerve damage?

Answer 37

Peripheral: Diabetes, chemotherapy-induced neuropathy. Central: Stroke, multiple sclerosis, spinal cord injuries.

Question 38

What are the two types of neuropathic pain sensations?

Answer 38

Continuous (burning/tingling) or episodic (electric-shock sensations).

Question 39

What causes nerve sensitisation?

Answer 39

Prostaglandins and other inflammatory chemicals lower the pain threshold.

Question 40

How does counter-stimulation reduce pain?

Answer 40

A-Beta fibers inhibit nociceptive signals in the dorsal horn.

Question 41

How does descending modulation reduce pain?

Answer 41

The brainstem releases neurotransmitters like endorphins, serotonin, and noradrenaline that block pain signals.