Somatosensory system

Question 1

what are sensory receptors

Answer 1

receptors that response to stimulation such as light energy, mechanical energy, chemical energy

Question 2

what is the sensory system made up of

Answer 2

association sensory cortex
secondary sensory cortex
primary sensory cortex
thalamus
receptors

Question 3

what are most of the sensory receptors in the somatosensory system called

Answer 3

Mechanoreceptors

Question 4

what are the 2 types of mechanoreceptors

Answer 4

fast adapting mechanoreceptor
slow adapting mechanoreceptor

Question 5

what is a fast adapting mechanoreceptor

Answer 5

adapt quickly
sudden activation
no continuous activation

Question 6

what is an example of a fast adapting mechanoreceptor

Answer 6

meissners corpuscles - detect light touch

Question 7

what is a slow adapting mechanoreceptor

Answer 7

respond for as long as the stimulus is activated

Question 8

what is an example of a slow adapting mechanoreceptor

Answer 8

Ruffini endings - stretch

Question 9

what is the specific area of the skin that is connected to a specific spinal nerve called

Answer 9

dermatome

Question 10

what happens when a spinal nerve is damaged

Answer 10

the area of skin that it controls (dermatome) will lose feeling and may experience pain

Question 11

what is the somatosensory touch pathway called

Answer 11

medial lemniscus pathway

Question 12

what is the process of the medial lemniscus pathway

Answer 12

1. touch receptors detect stimulus
2. sensory neurons signal spinal cord
3. signal moved up through dorsal column
4. signal reaches medulla
5. at the medulla the signal connects to the dorsal column nuclei
6. signal travels up to the medial lemniscus pathway
7. signal reaches thalamus
8. transferred to somatosensory cortex

Question 13

what does the primary somatosensory cortex do

Answer 13

receives sensory information from the thalamus in the medial lemniscus pathway

Question 14

where is the primary somatosensory cortex

Answer 14

postcentral gyrus in the parietal lobe

Question 15

what is somatopy

Answer 15

map like representation of the somatosensory cortex

Question 16

what is the sensory hormunculus

Answer 16

distorted representation of the body showing how much brain space in the primary somatosensory cortex is devoted to each body part

Question 17

who described pain as an aversive sensory and emotional experience which is caused by tissue damage

Answer 17

IASP, 2020

Question 18

what is the rare genetic condition where people cannot feel physical pain called

Answer 18

Congenital insensitivity

Question 19

what are nociceptors

Answer 19

sensory receptors responsible for detecting pain

Question 20

what are the 2 axons that primary afferent nerves travel to the spinal cord through

Answer 20

A delta fibres - carry signals for short durations eg prick
C fibres - slower signals for longer duration eg ache

Question 21

what is the pain pathway called

Answer 21

anterolateral pathway

Question 22

describe the anterolateral pathway

Answer 22

1. primary afferent nerve carries pain signal from nociceptor to spinal cord
2. pain signal travels to thalamus
3. thalamus sends to SC

Question 23

what is the difference in how pain and touch are carried

Answer 23

pain - contralaterally
touch - ipsilaterally

Question 24

what is central modulation

Answer 24

brains ability to influence and rewire how we experience pain

Question 25

who found that people who have experienced trauma experience reduced pain - central modulation

Answer 25

Larbig, 1991

Question 26

who devised the gate control theory

Answer 26

Melzack, 1965

Question 27

what is the gate control theory - melzqack, 1965

Answer 27

where pain signals are either transmitted to the brain or not , based on the activity of the nerve fibres gate open = pain signals can be transmitted - A delta & C fibres gate closed = pain signals cannot pass to the brain because touch pathway is activated by A beta fibres

Question 28

where is the gate control theory located

Answer 28

Substantia gelatinosa

Question 29

who found that swearing can reduce pain perception

Answer 29

Stephens, 2009

Question 30

who found that when we expect pain, we feel more pain

Answer 30

Atlas, 2010

Question 31

apart from swearing and expectation, what are 2 other factors that can affect pain perception

Answer 31

attention - distracted emotions

Question 32

what is the descending pain pathway

Answer 32

the pain signal is reduced to allow for functioning and survival but there is enough signal present to allow for response

Question 33

what area of the brain is involved in the descending pain pathway that detects the pain and helps with modulating the pain

Answer 33

periaqueductal gray

Question 34

how does the PAG reduce pain perception

Answer 34

electrical stimulation of PAG has a pain blocking effect

Question 35

alongside PAG, what other feature of the brain is involved in suppressing pain

Answer 35

raphe nuclei

Question 36

who found that central modulation isn't effective for people with chronic pain, even when theyve tried cognitive strategies to alleviate the pain

Answer 36

Mckracken 2003

Question 37

who found that central modulation only works for as long as a distractor is present, when a distractor reduces or leaves the pain can be felt

Answer 37

Engel 1977

Question 38

who can you include if you forget names

Answer 38

Pinel 2017