All four types of sensors contain protein channels.
Mechanosensors:
Hair cells in the cochlea are a type of mechanosensor that responds to vibrations caused by sound waves.
Muscle spindles sense the stretch of muscle cells or tendons
In the somatosensory system, pressure is transduced by stretching of the neuron membrane physically, opening sodium channels which polarizes the membrane (increase in cell voltage).
Thermoreceptor:
In our skin (dermis), bare nerve endings sense temperature
Snakes have pit organ to response to temperature with accuracy.
