Neuroscience Flashcards
What does the somatosensory system mediate?
Sensations from the whole body surface, including skin and deeper tissue.
What type of skin is found on the palmar surface of the hands and feet?
Glabrous skin
What is a prominent feature of glabrous skin?
Skin ridges
What are the 4 types of mechanoreceptors found in glabrous skin?
- Meissner corpuscles
- Merkel complexes
- Ruffini organs
- Pacinian corpuscles

Which mechanoreceptors are found close to the surface of the skin?
Meissner corpuscles and Merkel complexes
Which mechanoreceptors are found deeperin the skin?
Ruffini organs and Pacinian corpuscles
Where are the somata for skin mechanoreceptors found?
In the dorsal root ganglia
What does transmission of mechanoreceptor information to the brain generate?
The conscious experience of touch
Where in the superficial layers of the skin do the Meissner corpuscles lie?
In the peaks of the dermal waves.
Where in the superficial layers of the skin do the Merkel complexes lie?
In the epidermis border
Which part of the Merkel complex is the transducer?
The nerve ending, not the Merkel cell.
What type of energy do mechanoreceptors sense?
Distortion of skin
What is the structure of the mechanoreceptors?
Various encapsulated nerve endings
What is the range of the mechanoreceptors?
10nm to sub-damaging distortion
What is the sensitivity and dynamic range of mechanoreceptors?
0-1000Hz
What is the receptive field of the mechanoreceptors?
Ovaloid from 10mm2 to the entire hand.
How does transduction in the mechanosensory afferent occur?
An object touching the skin causes the sodium channels to stretch, opening them and allowing Na+ in, depolarising the cell.

Why won’t all stimuli affecting the mechanoreceptor be transduced into action potentials?
Because the receptor potential must reach threshold to generate an AP.
What are the 2 ways the mechanoreceptor can respond to a continuous stimulus?
Slowly- and rapidly-adapting
How does a slowly-adapting mechanoreceptor behave?
There’s an initial increased amount of nerve activity, but the frequency will reduce and remain relatively constant for the duration of the stimulus.
What do slowly-adapting mechanoreceptors inform on?
Duration of the event
How does a rapidly-adapting mechanoreceptor behave?
There’s an initial increased amount of nerve activity that quickly disappears.
What do rapidly-adapting mechanoreceptors inform on?
The change (not the duration)
True or false: most receptors of the nervous system are slowly adapting.
False: the brain really only cares about changes.































