Touch & Pain Flashcards
What are the two types of skin?
Glabrous – palms of hands and feet (no hair)
Hairy – everywhere else
What is the name of skin with no hair?
Glabrous
Does skin sensation always bypass the spinal cord before going to the brain?
Yes
What are the 4 senses of the skin?
touch (‘mechanical’ stimuli)
pain
body sense (proprioception)
temperature
What does merkel’s disc sense?
fine details (eg braille)
What does messiner corpuscle sense?
Flutter (things slipping through your fingers)
What does the ruffini organ sense?
Stretching
What does the paccinian corpuscle sense?
vibrations & fine texture (eg using a pen/tool)
Which have larger receptive fields, messiner’s corpsucles or paccian copuscles?
paccinian
What do 2 point thresholds tests look at?
– the smallest separation of 2 separate but adjacent points of stimulation on the skin that just produces two distinct impressions of touch
Is there plasticity in the acuity of someone’s fingertips?
Yes
What is your kinaesthetic sense?
Your sense of your own movement (direction, weight, extent)
What is the difference between spatial and temporal cues when perceiving texture?
Spatial cues – bumps and grooves, when finger is stationary or moving
Temporal cues – only when move finger across surface
What type of tactile receptors do temporal cues use?
paccinian corpuscles
What is the predominant symptom of tactile agnosia?
A patients cannot identify objects by touch, but no problems with spatial processing
What is the predominant symptom of tactile extinction?
Patient has problems with tactile recognition (eg if you stimulate both arms, they will only feel one) but without problems in object recognition
What is Aristotle’s illusion?
If you cross fingers and touch your nose - can cause you to feel like you’ve got 2 noses
What is the cutaneous rabbit illusion?
- tapping people on the arm
- stimulus – widely separated taps
- perception – evenly space jumps
Which fibres are related to pain and how?
A delta fibres – fast pain (sharp), pin prick, pinches, extreme temperature
C fibres – slow pain (dull) – many types of pain, (n.b. mild stimulation can be pleasurable!)
What type of pain do A delta fibres signal?
Fast pain (sharp), pin prick, pinches, extreme temperature
What type of pain do C fibres signal?
slow pain (dull) – many types of pain, (n.b. mild stimulation can be pleasurable!)
What is battlefield agnosia?
When someone doesn’t experience pain because they are in a high adrenaline situation
What is proprioception?
The awareness of posture, movement, and changes in equilibrium, and the knowledge of position, weight, and resistance of objects in relation to the body
