Sensory systems (physiology of pain) Flashcards Preview

Year 2 Neuro (JK) > Sensory systems (physiology of pain) > Flashcards

Flashcards in Sensory systems (physiology of pain) Deck (23):
1

List some of the different receptor types

nociceptor, mechanoreceptor, chemoreceptor, thermoreceptor, proprioceptor

2

Pacinian and Meissners corpuscles

pacinnian - deep pressure
meissners - light touch

3

What is the receptive field?

area in which the receptor responds to the stimulus

4

What is the adequate stimulus transduced into?

generator potential

5

What does the size of receptor potential tell us?

intensity of stimulus

6

Does amplitude or frequency of AP tell us about intensity of stimulus?

frequency

7

What does the receptive field tell us about the stimulus?

location

8

What 2 things is acuity dependent on?

density of innervation and size of receptive field

9

A beta fibres

large, myelinated - touch, pressure, vibration

10

A delta fibres

small, myelinated, cold fast pain, pressure

11

C fibres

unmyelinated - warmth and slow pain

12

What primary afferent fibres mediate proprioception?

A alpha and A beta

13

Termination of sensory information?

somatosensory cortex of post central gyrus

14

What may convergence underlie?

referred pain

15

2 types of adaption

fast and slow adapting

16

1 positive and 1 negative of convergence

saves on neurons
reduces acuity - increase receptive field size

17

Lateral inhibition positives

gives better definition of boundaries and cleans up sensory information

18

What is perception?

state of mind

19

Explain the gate control theory

mechanoreceptors activate inhibitory interneurons
release endorphins to inhibit transmitter release from nociceptive fibres to close the gate
descending pathways from PAG and NRM

20

NSAIDS - how do they work?

inhibit cyclo-oxygenase which converts arachidonic acid to prostaglandins
work well with pain associated with inflammation

21

What do prostaglandins sensitise nociceptors to?

bradykinin

22

Local anaesthetics - how do they work?

block sodium action potential and hence axonal transmission

23

opiates - how do they work?

reduce nociceptor sensitivity and activate descending pathways to block NT release in dorsal horn