block 5 lecture 9 pain and nociception

Question 1

what is pain?

Answer 1

unpleasant sensory and emotional experience

Question 2

what is nociception?

Answer 2

neural process of detecting, encoding and processing noxious stimuli

Question 3

advantages of pain?

Answer 3

protects the body, sense damaging stimuli, avoid harmful situations, forces you to rest when injured, during sleep you toss to avoid bed sores

Question 4

disadvantages of pain?

Answer 4

may not be usefull such as in chonic, cancer, rheumatic, pain may persist after the tissue has healed

Question 5

how can pain be characterised based on location?

Answer 5

visceral and somatic (deep and superfiscial)

Question 6

how can pain be characterised on duration?

Answer 6

acute and chronic

Question 7

what is the journey of the pain pathway?

Answer 7

nociceptors, primary afferent fibers, dorsal root ganglion, spinal cord, higher brain centers

Question 8

what part of the body dosent have nociceptors?

Answer 8

brain

Question 9

what are at the end of nociceptors?

Answer 9

free nerve endings

Question 10

what are the different nociceptors?

Answer 10

thermal, mechanical, chemical, polymodal and sleeping

Question 11

what are the primary afferent large diameter fibers and what do they do?

Answer 11

Aalpha and Abeta, low threshold mechanoreceptors - detect touch, rapid conduction

Question 12

what are the primary afferent small diameter fibers and what do they do?

Answer 12

Adelta and C fibers, they are nociceptors and thermoceptors, slow conduction

Question 13

what fibers are for thermal and mechanical stimulus?

Answer 13

Adelta fibers

Question 14

what fibers are for polymodal?

Answer 14

C fibers

Question 15

aspects of first pain?

Answer 15

Adelta fibers, fast sharp prickling sensation, easily localised, short duration, mechanical and thermal receptors

Question 16

aspects of second pain?

Answer 16

C fibers, dull aching burning, poorly localised, slow onset, long duration, poly modal receptors

Question 17

what are receptors on nociceptors activated by?

Answer 17

noxious stimuli

Question 18

what do noxious stimuli generate in nociceptors?

Answer 18

generates a receptor potential

Question 19

what does a receptor potential do?

Answer 19

depolarize membrane and generate an action potential

Question 20

where are the cell bodies of nociceptors?

Answer 20

dorsal root ganglia

Question 21

how does the action potential in nociception enter the spinal cord?

Answer 21

dorsal horn

Question 22

in nociception what do voltage gated calcium ions trigger?

Answer 22

release of neurotransmitter and activates second neurons

Question 23

what is congenital analgesia?

Answer 23

insensitivity to pain

Question 24

what are the symptoms of congenital analgesia?

Answer 24

bruises, cuts, burns, scars, missing body parts, infection

Question 25

what do Adelta fibers innovate?

Answer 25

laminae 1

Question 26

what do C fibers innovate?

Answer 26

laminae 2

Question 27

where do second order neurons take information?

Answer 27

to the laminae 4-6

Question 28

in the spinothalamic tract where do first order neurons synapse with the second order neuron?

Answer 28

dorsal root ganglion

Question 29

in the spinothalamic tract what do second order enurons do?

Answer 29

cross the midline and travel up the spinal cord through the medulla to the thalamus to the somatosensory cortex

Question 30

what happens in the contralateral pathway?

Answer 30

sensory inputs cross in the spinal cord and ascend on the other side

Question 31

whata re the main neurotransmitters involved in the pain pathway?

Answer 31

glutamate and substance P