L06

Question 1

what is nociception

Answer 1

Nociception is the sensory nervous system’s process of encoding potentially harmful stimuli. Signals are sent from nociceptors to the central nervous system.

Question 2

how do sensory neurons detect stimuli

Answer 2

through nociceptors

Question 3

nociceptors are ion channels

Answer 3

true

Question 4

what are the stages of nociceptive signaling

Answer 4

TRANDUCTION

TRANSMISSION (into the central nervous system)

MODULATION

PERCEPTION

Question 5

what transmits the nociceptive signal to the central nervous system

Answer 5

primary afferent nociceptor

Question 6

where does modulation take place

Answer 6

in the dorsal root ganglia in the spinal cord

Question 7

where does the signal go after the spinal cord

Answer 7

the thalamus

Question 8

how is a signal perceived

Answer 8

because of the connections between the thalamus and the cortex

Question 9

what are the neural pathways that connect the thalamus to the cerebral cortex

Answer 9

Thalamocortical projections

Question 10

what are the types of nociceptive fibers

Answer 10

A Beta

A Delta

C

Question 11

what stimulates A beta fibers

Answer 11

non-noxious mechanical stimuli

Question 12

what stimulates A delta fibers

Answer 12

noxious mechanical stimuli

Question 13

what stimulates C fibers

Answer 13

noxious heat and chemical stimuli

Question 14

what are the features of A beta fibers

Answer 14

myelinated

large diameter

involved in proprioception and light touch

Question 15

does A beta have a thermal threshold

Answer 15

NO

Question 16

what are the properties of A delta fibers

Answer 16

lightly myelinated

medium diameter

involved in mechanical, thermal, and chemical nociception

Question 17

what is the thermal threshold for type I A delta fibers

Answer 17

53 degrees

Question 18

what is the thermal threshold for type II A delta fibers

Answer 18

43 degrees

Question 19

what are the features of C fibers

Answer 19

unmyelinated

small diameter

involved in innocuous temperature, itch, as well as mechanical, thermal, and chemical nociception

Question 20

what channels mediate nociception

Answer 20

Transient receptor potential (TRP) channels

Question 21

what ions are transported by TRP channels

Answer 21

Na+ and Ca 2+

Question 22

how many subunits are there in TRP channels

Answer 22

4

Question 23

how many helices does each TRP subunit have

Answer 23

6

Question 24

what TRP channels detect heat

Answer 24

TRPV1

TRPV2

TRPV3

TRPV4

Question 25

what TRP channels detect PH

Answer 25

TRPV1 (acid) TRPA1 (acid/base)

Question 26

what TRP channels detect reactive chemicals

Answer 26

TRPA1 TRPV1

Question 27

what TRP channels detect environmental cold

Answer 27

TRPM8

Question 28

what TRP channels detect cold hyperalgesia

Answer 28

TRPA1

Question 29

what TRP channel has the threshold of 17 degrees (noxious cold)

Answer 29

TRPA1

Question 30

what TRP channel has the threshold of 25 degrees (non noxious cold)

Answer 30

TRPM8

Question 31

what TRP channel has the threshold of 25 to 37 degrees (non noxious cold)

Answer 31

TRPC5

Question 32

what TRP channel has the threshold of 27 to 34 degrees (non noxious heat)

Answer 32

TRPV4

Question 33

what TRP channel has the threshold of 32 to 40 degrees (non noxious heat)

Answer 33

TRPV3

Question 34

what TRP channel has the threshold of 43 degrees ( noxious heat)

Answer 34

TRPV1

Question 35

what TRP channel has the threshold of 52 degrees ( noxious heat)

Answer 35

TRPV2

Question 36

what TRP channel is activated by mint and menthol

Answer 36

TRPM8

Question 37

what TRP channel is activated by Cannabidiol

Answer 37

TRPA1 TRPV1

Question 38

what TRP channel is activated by Chilli and capsaicin

Answer 38

TRPV1

Question 39

what are the classes of pain

Answer 39

normal inflammatory neuropathic

Question 40

what pain is nociceptive

Answer 40

normal inflammatory

Question 41

what pain is pathophysiologic

Answer 41

neuropathic inflammatory

Question 42

what are the types of nociceptive pain

Answer 42

somatic visceral

Question 43

what are the features of somatic pain

Answer 43

- Pain arises from the peripheral nervous system (skin, muscles, joints, bones, and connective tissues) - Localised to specific region - Stimulation nociceptive nerve fibers (Aδ and C fibers) - Muscle cramps, sprains etc - Usually responsive to pain-relief

Question 44

what are the features of visceral pain

Answer 44

- Pain arises from the viscera (uterus, intestine, kidneys, stomach) - Diffuse pain, often difficult to pinpoint to a specific region - Nociceptive nerve fibers (Aδ and C fibers) - Autonomic system symptoms nausea, sweating, changes in heart rate/blood pressure. - Appendicitis, dysmenorrhea, bowel obstruction - Poorly responsive to pain relief

Question 45

what are the mediators of inflammatory pain

Answer 45

histamine serotonin bradykinin prostaglandins ATP

Question 46

how is inflammatory pain treated

Answer 46

Cox2 inhibitors (NSAIDs) Opioids

Question 47

what do inflammatory pain mediators modulate

Answer 47

TRP, NaV, and KV channels to enhance pain sensitivity.

Question 48

what happens in neuropathic pain

Answer 48

Nerve injury alters NaV, CaV and KV channel function and expression in nociceptors.

Question 49

how is Neuropathic pain treated

Answer 49

tricyclic antidepressants anticonvulsants Na+ channel blockers NMDA receptor antagonists opioids

Question 50

demyelination can lead to firing without a stimuli

Answer 50

yea

Question 51

what channel does lidocaine block

Answer 51

voltage-gated Na+ channel

Question 52

how does lidocaine work

Answer 52

Lidocaine reversibly binds to the inner pore of voltage-gated Na+ channels when they are in their open and inactivated states. Lidocaine has greater affinity for inactivated channels compared to resting channels. Blocks the inner pore Non-selective