Pain

Question 1

What is pain?

Answer 1

An abstraction of nociception

Question 2

What tract is pain through?

Answer 2

Spinothalamic tract

Question 3

What are nociceptors?

Answer 3

Free nerve endings

Question 4

What do nociceptors do?

Answer 4

Detect stimuli that caused damage to tissue or that may cause damage

Question 5

What stimulates nociceptors?

Answer 5

Intense mechanical stimulation, intense hot or cold, or various chemicals released by or in response to tissue damage

Question 6

What happens when tissue is injured?

Answer 6

Nociceptors generate a receptor potential (local and graded/amp modulated)
If the receptor potential depolarizes the cell to threshold, then AP (frequency modulated) is generated
Info travels to the CNS and also causes reactions in the periphery at the site of injury
Nociceptor stimulation causes an axon reflex that enhances inflammation
Nociceptors release glutamate and other neuropeptides
At site of damage, there is a release of potassium, serotonin, and substance p and calcitonin
At the periphery, these chemical cause dilation of arterioles (redness) and leakage of plasma from venules (swelling) and attraction of phagocytes (for repair and cleaning)

Question 7

Do the chemicals released during damage cause the nociceptive endings to become sensitized and increase susceptibility to pain?

Answer 7

Yes

Question 8

What is our response to pain?

Answer 8

Aspirin or aspirin-like drugs - inhibit the synthesis of prostaglandins and reduce pain and inflammation
Stop whatever you’re doing and protect

Question 9

Does pain information just go to the somatosensory cortex?

Answer 9

No, it also goes to the limbic system and the cingulate cortex (emotional response)

Question 10

Do steroids stop entire cascade?

Answer 10

Yes

Question 11

What do prostaglandins cause?

Answer 11

Redness, pain, and inflammation

Question 12

What is the function of pain?

Answer 12

To warn us of damage
Encourages us to protect the injured area

Question 13

Would freedom from pain be a good thing?

Answer 13

No

Question 14

What is physiological pain?

Answer 14

Tissue damage
Also called nociceptive pain

Question 15

What is physiological pain cased by?

Answer 15

Direct stimulation of nociceptors

Question 16

What cells is physiological pain conveyed by?

Answer 16

A delta (sharp and sort-lived) and C fibers (slow, dull, burning pain)

Question 17

Is physiological pain intensified by the peripheral mechanisms that occur at the site of damage?

Answer 17

Yes, this feedback system increases and prolongs the physiologic pain

Question 18

What are the results of physiological pain?

Answer 18

Reflexive withdrawal and modify behavior to protect the affected area

Question 19

What is neuropathic pain?

Answer 19

Not useful, maladaptive pain

Question 20

What is neuropathic pain caused by?

Answer 20

Damage to the nervous system that changes CNS connections (due to plasticity)
Chronic pain

Question 21

When does neuropathic pain occur?

Answer 21

When some regeneration happens and fibers now stimulate nociceptive pathways when the stimulation in the periphery was not painful

Question 22

What is another way to categorize pain?

Answer 22

Acute vs chronic

Question 23

What is acute pain?

Answer 23

Protective mechanism
Signaling tissue damage
Localized

Question 24

What is chronic pain?

Answer 24

Caused by inflammation, arthritis, nerve entrapment, gun shot wounds, surgery, migraine, cancer, spinal cord injury, stroke, tumors, and more

Question 25

What is visceral pain?

Answer 25

Organ pain
Gall stones, kidney stones, ulcer, appendicitis

Question 26

What is somatic pain?

Answer 26

Superficial pain and deep pain

Question 27

What is superficial pain?

Answer 27

Pain that arises from the skin
Pinprick, pinching, hitting thumb with a hammer

Question 28

What is deep pain?

Answer 28

Pain that arises from connective tissue, bones, joints, and muscles
Tends to be longer lasting and nagging

Question 29

What is referred pain?

Answer 29

Feeling pain in a different area than was actually injured or hurting

Question 30

What is projected pain?

Answer 30

Pain that is projected to areas that are innervated by nerves that are compressed or damaged
Usually out further from where damage is (shoulder injury felt in wrist or elbow)

Question 31

What is neuralgia?

Answer 31

Spontaneous nerve pain that comes in waves following a noxious stimulus that has acted on the sensory neurons for a long period of time

Question 32

Where does neuralgia occur?

Answer 32

It is restricted to regions supplied by the affected nerve or nerve root

Question 33

What is the gate control theory?

Answer 33

Rubbing area of pain stimulated non-nociceptive cutaneous receptors and their afferents to reduce the pain that is felt

Question 34

What is CIPA or congenital insensitivity to pain with anhidrosis?

Answer 34

A very rare condition where you do not feel pain
Due to loss of unmyelinated sensory fibers or reasons stemming from the CNS

Question 35

Does the limbic system (hippocampus, amygdala, and cingulate gyrus) have input to the brainstem pain areas?

Answer 35

Yes, it is thought to play a role in affective response to painful stimuli

Question 36

Does cognitive regions also play a role in the affective response to pain?

Answer 36

Yes
Cultural values, anxiety, attention, and suggestion all have a profound effect on the pain experience