Pain and analgesics first half of 1

Question 1

What is pain?

Answer 1

The subjective conscious appreciation of a stimulus that is causing, or threatening to cause, tissue damage

Question 2

What is nociception?

Answer 2

The physical process of detection and transmission of damaging or potentially damaging (noxious) stimuli

Question 3

What are nociceptors?

Answer 3

Structures that detect noxious stimulus

Question 4

What is algesia?

Answer 4

The induction of a condition leading to nociception and pain

Question 5

What is analgesia?

Answer 5

Reduction or prevention of either nociception or pain without loss of consciousness

Question 6

What is the detection of touch?

Answer 6

Mecanoception

Question 7

Which specific structures are involved in the perception of touch?

Answer 7

Merkel’s Disc, Pacinian Corpuscle, Meissners Corpuscle

Question 8

What are the two main types of nociceptor?

Answer 8

Polymodal, mechanical

Question 9

What level of mechanical stimuli do both types of nociceptor respond to?

Answer 9

High intensity

Question 10

What level of thermal input can stimulate polymodal nociceptors?

Answer 10

> 45 degrees, <10 degrees

Question 11

What level of thermal stimuli can stimulate mechanical nociceptors?

Answer 11

> 60 degrees

Question 12

What is the order of structures for detecting a noxious stimulus?

Answer 12

Skin/viscera–> Sensory receptor–> primary afferent axon–> spinal cord

Question 13

What are the types of receptor in nociceptors?

Answer 13

ASIC (acid sensing ion channel), Purinergic receptors (P2x3), Voltage gated Na+ channels, VR-1/TRPV-1

Question 14

What is the main agonist of ASICs?

Answer 14

Protons

Question 15

What is the main agonist of Purinergic receptors?

Answer 15

ATP

Question 16

What type of stimulation do purinergic receptors respond to?

Answer 16

High intensity mechanical stimulation

Question 17

What type of stimulation do voltage gated sodium channels respond to?

Answer 17

Mechanical stimulation

Question 18

What are the main agonists of VR-1/TRPV-1?

Answer 18

H+, high levels of heat and capsaicin

Question 19

Speed of nociceptive APs compared to touch APs?

Answer 19

Slower

Question 20

Why are nociceptive APs slower than touch ones?

Answer 20

The C fibres are very thin and unmyelinated

Question 21

Which types of fibre are used for nociception?

Answer 21

C and a delta

Question 22

Which type of nociceptor is linked to c fibres?

Answer 22

Polymodal

Question 23

Which type of nociceptor is linked to A delta fibres?

Answer 23

Mechanical

Question 24

Why do APs flow down Adelta fibres quicker than C fibres?

Answer 24

The Adelta fibres are myelinated

Question 25

Why is there an initial pain felt, then a throbbing?

Answer 25

Different fibres transmit at different speeds so one transmits slower after the other

Question 26

Which fibres are responsible for the initial pain?

Answer 26

A delta

Question 27

Which pain fibres are responsible for the second pain?

Answer 27

C fibres

Question 28

Which receptors detect reasonable temperatures (10-40 degrees)?

Answer 28

Thermoreceptors

Question 29

Which receptors detect extreme temperatures?

Answer 29

Cold/heat pain receptors

Question 30

Why do thicker fibres transmit APs quicker?

Answer 30

There is less resistance

Question 31

Where does sensory input enter the spinal cord?

Answer 31

Through the dorsal root

Question 32

Where is the first synapse (in the spinal cord) that is responsible for nociceptive input into the brain?

Answer 32

The most dorsal part of the spinal cord