Your sense of smell works almost the same way, except the sense organs are olfactory cells located in your nasal cavity. Also, instead of four different types, there are probably around 1,000 different types of olfactory cells, each of which responds to a different type of chemical. For more information about smell, go to this page on the sense of smell Pain sensors respond to chemicals, too, except that the chemicals are released by damaged cells in the body. Now for the mechanical senses. When your skin is touched, it pushes on the Meissner's corpuscles, changes their shape, and sends a signal to the brain.
Pacinian corpuscles detect pressure in a similar way.
You can divide the ear into an outer part, a middle part, and an inner part . When the eardrum vibrates it pushes and pulls on a small bone called the hammer, which pulls on another small bone called the anvil, which pulls a third bone called the stirrup in and out of an oval window . On the other side of the oval window is the fluid-filled inner ear. The motion of the stirrup sets the fluid in motion, which sets little hairs on sensory receptors called hair cells in motion also. When the hairs on the hair cells are pulled back and forth, a signal is sent to the brain.