SOMATOSENSATION-TOUCH Flashcards
What is another word for pain?
Nossiseption
How can we quantitatively test touch perception?
- Two point discrimination threshold
- Letter identification
Where are mechanically gated cation channels found?G
Found in spike generating zones of the axons of mechanoreceptors
What happens when stretch is detected?
Stretch or lipid tension in membrane causes Na+ channels to open thus depolarising the cell
Can strucutral proteins also be stretched to open channel?
YES!
What can G protein coupled receptors be involved in?
PAIN SENSATION
because receptors are slow to activate and LONG LASTING
What are the 4 types of mechanoreceptors?
Merkel cells, Messiner corpuscle, ruffini endings, and Pacinian corpuscle
What are merkel cells?
SA1 (slowly adapting)
- 3 mechanoreceptors associated with a single axon
- Hairy and glaborous skin
- Is SUPERFICIAL layer
What are messiner cells?
2 mechanoreceptros associated with a single axon
- Rapidly adapting (RA1)
- GLABOROUS SKIN (palms of hands-fine touch tasks)
- SUPERFICIAL LAYER in dermal papillae
What are ruffini endings?
- SA2 (slowly adapting)
- hairy AND glaborous skin
- DEEP tissue- dermis
What are pacinian corpuscles?
- RA2 (rapidly adapting)
- DEEP tissue (dermis)
- Hairy and glaborous skin type
What are free nerve endings in the skin cross section associated with?
PAIN SENSATION
Do unipolar neurons have dendrites?
NO! Just all axons
The size of the receptive fields in mechanoreceptors is…
Reflected in their relative position in the skin
Why do messiners corpuslces have much smaller receptive fields than the RFs of pacinian corpuslces?
Because pacinian corpuslces are much deeper in the skin so LARGER receptive field