Tongue, nose, and skin as sensory organs

Our body has organs that play a role or a special tool receiving stimulation that comes from outside the body, hereinafter called a sensory organ. In each of the senses have receptors (excitatory recipient cells) are sensitive to any particular stimuli such as chemicals, light, or physical stimuli such as pressure, touch and vibration.

Tongue, the taste buds
Sensitive to chemical stimuli are soluble in water. This stimulus will be received by the nipple-nipple taster in which contains nerve cells that acts as a receptor, in which the nipple-nipple taster is responsible for the characteristic flavor alone and dispersed on the surface of the tongue, namely:
a. the front end for a sweet taste
b. the end of the front edge to the saltiness
c. the side to taste sour
d. the back to a bitter taste.

Stimulation received further forwarded to the tasting center in the brain.

Nose, as the sense of smell
In it there are many receptors that are sensitive to the chemicals in the form of gas, which is associated with the smell and aroma.
The receptors are located in the mucous membrane, the gas that goes into the nose will be mixed with mucus would then stimulate the taste or smell nerve cells to receive stimuli and proceeds to smell center in the brain.

Leather, as the sense of touch
This allows for the spread of skin surface of nerve cells that are sensitive to heat, cold, touch, pressure, and even pain, such as:
a. to touch: Meissner nerve cells
b. for pressure: nerve cells Paccini
c. to heat: Ruffini nerve cells
d. for the cold: nerve cells krausse
e. for pain: nerve cells freely.