Touch
| The human sense of touch relies on mechanoreceptors
that are modified
dendrites of sensory neurons. Mechanoreceptors are excited by
stimuli such as pressure and touch, two forms of mechanical energy.
Bending or stretching of the plasma membrane (the membrane at the boundary
of every cell that acts as a selective barrier and regulates the cellchemical composition) on a
mechanoreceptor increases its permeability to
both sodium and potassium ions from the cellresulting
in a change of charge across the membrane (depolarization). Receptors
that detect light touch are close to the surface of the skin. Their
membranes can become depolarized by very slight inputs of mechanical
energy. Receptors responding to strong pressure and vibrations in the
body are found in deep skin layers. |
Activities
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