Pain

Question 1

Define pain

Answer 1

Complex- unpleasant sensory /emotional experience associated with actual or potential tissue damage

Question 2

What is the pain threshold

Answer 2

Lowest intensity of a stimulus which a subject recognises as pain

Question 3

Name 2 types of pain fibers

Answer 3

Myelinated A-delta ( transmit fast pain )
Unmyelinated C fibers : slow dull pain

Question 4

What is analgesia

Answer 4

the absence of pain in response to a stimulus which would normally cause pain

Question 5

What is hyperalgesia

Answer 5

An increased response to a stimuli that is painful

Question 6

What is paresthesia

Answer 6

an abnormal sensation spontaneous or evoked

Question 7

What is somatic pain and give 2 examples

Answer 7

A superficial/cutaneous pain evoked from tissues eg skin,bone ( e.g burn or hitting hand on blunt object )

Question 8

What is visceral pain and give an example

Answer 8

Pain that originates in an internal organ - eg appendicitis

Question 9

What is neuropathic pain

Answer 9

Pain originating from a nerve problem eg trigeminal neuralgia

Question 10

What is psychogenic pain

Answer 10

Pain that an individual feels but the cause is emotional not physical

Question 11

What is referred pain and give an example

Answer 11

Pain that is referred from one area to a different area ( eg heart pain from a heart attack can be felt in the mandible ,)

Question 12

Name 5 DIFFERENT types of oral facial pain and an example

Answer 12

1. Local - tooth abscess
2. Referred pain - heart to the jaw
3. Neurological pain - herpes zoster/trigeminal neuralgia
4. Vascular pain - migraine
5. Psychogenic - some TMJ disorders

Question 13

Name the 5 steps of pain transmission

Answer 13

1. Event
2. Transduction
3. Transmission of impulse
4. Perception of the pain
5. Modulation of the pain

Question 14

Name 2 types of nociceptors

Answer 14

Mechanosensitive- respond to stretch and tissue damage

Chemosensitive - respond to chemical mediator release -

Question 15

Discuss the pain pathway from the event happening to transduction of the pain

Answer 15

Noxious stimuli ( pin prick) sensed by nociceptors ( sensory pain receptors ) that then stimulate a first neuron to start transmission of pain

Question 16

Describe the transmission of pain

Answer 16

Involves 3 neurons
Stimuli sensed by nociceptors and then :
1. 1st order neuron takes the impulse from sensory receptor to the dorsal horn of the spinal cord

2. 2nd order neurons takes impulse from dorsal horn spinal cord to thalamus (via spinothalamic tract)
3. 3rd order neuron takes the impulse from thalamus to cerebral cortex where impulse perceived

NB Gate control theory explains a “gate “ between the 1st and 2nd neuron in spinal cord allowing gate control theory pain to arise and inhibitory impulses from brain can also work at the spinal cord level .

Question 17

What happens after the transmission of a pain impulse to cerebral cortex

Answer 17

special areas of cortex perceive the pain ( intensity and location etc ) and modulate a response - can be either facilitate or inhibit ( which is why people perceive pain differently )

Question 18

Name 5 methods of pain control

Answer 18

1. remove the stimulus
2. Increase the pain threshold - ie pain relief
3. Block impulse pathway
4. Prevent a pain reaction - ( suppress the coerebral cortex ) -General anaesthetic/opiates
5. Psychomotor methods- hypnosis /councilling

Question 19

Why does rubbing an area where injured help reduce pain

Answer 19

Gate control Theory

Spinal cord acts as a gate ( ie between a 1st and second order neuron ) that if opened lets impulses pass and if shut not - so if 2 stimuli coming from the same area ( ie pain and rubbing ) less of the “pain can get thru as the rubbing impulse also competing to get through the gate- so less pain gets thru to cerebral cortex and so pain is lessened.
The gate control also allows inhibitory messages from brain to the gate in the spinal cord decreasing the “pain fiber message “

Question 20

What is the gate control theory

Answer 20

Mechanism in spinal cord which acts as a gate for pain transmission and so you pain experience depends on how far the gate is open or closed
Open too long too much pain enters ( chronic pain )
Shut or 2 parts of the body using the gate - less pain thru as hard to process both pathways eg massage area decreases pain in the area ( as pain and massage sensation are competing for the gate )
Also inhibitory messages from the brain can act at the gate decreasing pain impulse .

Question 21

What is central sensitisation

Answer 21

Hypersensitive to a stimulus that not normally painful

Question 22

Why does central sensitisation occur

Answer 22

extra membrane excitement
Increased synapses working
Less inhibition

Question 23

Name 2 types pain fibers and what they do

Answer 23

Myelinated A-delta fibers :transmit fast pain ( sharp)

Unmyelinated C fibers :transmit slow dull pain