7 sensory systems

Question 1

why do we need sensory systems

Answer 1

• maintain homeostasis
• detect and react to changes in environments
• protect the body from damaging stimuli

Question 2

what are the touch receptors

Answer 2

• mechanoceptors (pressure)
• thermoceptors (temp)
• nociceptors (noxious stimuli - pain)

Question 3

what are the types of nociceptors

Answer 3

• thermoreceptors (extreme temps)
• mechanoreceptor (intense pressure)
• polymodal (high intense mechanical, chemical and thermal stimuli)

Question 4

is the pain always felt at the site of injury

Answer 4

no
eg heart attack pains been felt in arm

Question 5

is there a specific pain region in the brain

Answer 5

no

Question 6

can pain become less sore, if so how

Answer 6

yes, there are modulators which can make 2nd instance of pain less sore due to previous experience

Question 7

steps of pain transmission pathway

Answer 7

1. transduction
2. transmission
3. relay
4. interpretation
5. modulation

Question 8

what nerve fibres are the first pain related with

Answer 8

A epsilon fibres

Question 9

are A epsilon fibres myelinated

Answer 9

yes

Question 10

what nerve fibres are the second pain related to

Answer 10

C fibres

Question 11

what type of pain is first vs second

Answer 11

first - sharp pain

second - delayed long lasting pain

Question 12

what does the myelin allow

Answer 12

the action potential to maintain

Question 13

where is the dorsal route found

Answer 13

outside the cns

Question 14

what is the excitatory neurotransmitter in nociceptive pathways

Answer 14

glutamate

Question 15

how do nociceptive pathways project to the brain

Answer 15

via the spinothalmic tract - descending inhibition and perception

Question 16

where do nociceptive pathways synapse

Answer 16

in the dorsal horn of the spinal cord

Question 17

what does peripheral sensitisation cause

Answer 17

increase sensitivity to the skin
eg suburn making skin more sensitive

Question 18

what does central sensitisation cause

Answer 18

structural and chemical changes at the synapse
eg chronic pain

Question 19

what can modulate perception of pain

Answer 19

previous experiences, mood, genetics etc

Question 20

what causes acute/physioloical pain

Answer 20

activation of A epsilon fibres and C fibres

Question 21

what is acute pain related to

Answer 21

actual or potential tissue injury, initiates protective reflexes

Question 22

what is the gate theory of pain

Answer 22

pain signals can be interrupted in the spinal cord which acts as a gate

Question 23

can people with heart issues have cox inhibitors

Answer 23

NO

Question 24

why is paracetamol thought to be so good

Answer 24

affects many pathways

Question 25

how do local anaesthetics work

Answer 25

by intracellular blocking of Na channels

Question 26

steps of local anaesthetics mode of action

Answer 26

1. unionised LA enters cell 2. LA becomes ionised intracellularly 3. LA blocks Na channels 4. Pain signalling inhibited

Question 27

what primarily mediates analgesia

Answer 27

activation of U receptors

Question 28

what does inflammation do in regards to na channels

Answer 28

increase

Question 29

what does nerve damage or cns damage do in regards to na channels

Answer 29

increase some channels and decrease others