The senses!!!

TasteThere are about 10,000 taste buds on the tongue, clustered in papillae (those buttons for all your language). Taste buds are clusters of nerve cell bodies that trace thin grooves in the taste, and appear as microscopic clusters of bananas.
Taste bud
The molecules of the food we eat is mixed with saliva and find their way between rows and on the surfaces of neurons. Like a key fitting into a lock, these molecules open pores in cell membranes and begin the process of neuron firing in much the same way how do neurotransmitters between neurons.
There are only four basic tastes - that is, only four individual molecules which respond to as many neurons in your language:

    Salado (most at the end of the tongue)
    Dulce (mostly at the tip of the tongue)
    Salado (mostly in the front side of the tongue)
    Acid (mostly in the rear side of the tongue)
Flavors
We say "most" because there is no clear boundary here, and all the flavors can be found to some degree in any part of the language, and even in some parts of the inside of your mouth and lips.
There may be a fifth taste: Umami "(in, for example, monosodium glutamate).
Note also that your tongue is sensitive to the touch (hence the idea of ​​texture in food), and temperature and, of course, pain. Jalapeno peppers, for example, have a certain flavor in the ordinary sense, but also provide us with a delicious () sensation of pain. You can find useful to know that if your burning mouth eat peppers, help drinking milk because milk fat dissolve the active chemical (capsaicin), while only water scatters around.
Perhaps the greatest part of our sense of taste is, curiously, the smell ...
Smell
Smell and taste work: It is also a sense of "lock and key." This time, it is a matter of moist air that passes through a specialized mucous membrane of the size of a coin on top of the nasal cavity.
Olfactory bulb
With smell, seem to respond to the presence of some combination of seven basic molecules:
FloralMentholatedMuskyAcre (like spices)Camphor (as mothballs)Ethereal (like dry cleaning fluids)Putrid (like rotten eggs)
But we are far from knowing that these are the basic flavors - some researchers think that there are many more.
The chemical senses are extremely sensitive, and this is especially so with the smell. We can detect acetic acid (vinegar smell) at a concentration of 500,000,000,000 molecules per liter of air. But the dog beat us in this:! They can detect a concentration of 200,000 molecules per liter of air!
There has been considerable debate for many years about the existence of a sense similar to the smell that can detect the presence of molecules called pheromones. Many animals can clearly smell the presence of a potential mate over long distances. People can certainly smell other people - but is there a special smell that is not really a particular aroma, but leads us to feel, well, these special feelings of "I love you"? . I think not, but there are many who disagree with me.
Touch
The skin actually has three types of sensations: pressure, temperature and pain.
The pressure is a matter of mechanical distortion, the twist of a "hair" of a hair cell. Not really a hair, of course, but an extended version of a dendrite. When folded, the tension causes the opening of pores, ion exchange, and, of course, the firing of the neuron. There is, anyway, three different types of receptors of pressure: light touch, pressure and vibration.
The temperature seems to have a direct influence of heat or cold to open certain ion channels. We found three: one for the cold, another for warmth, and one for the extreme heat. Perhaps you also for the extreme cold or even the templadez.
Interestingly, menthol can also activate cold receptors, and makes us think we are feeling cold When did not. It is also peculiar that when we play a "thermal grill" - a surface alternating hot and cold lines - do not feel neither hot nor cold, but pain!
Skin sensory neurons
Talk of pain separately, but basically, the pain is a matter of detecting certain chemicals that indicate tissue damage. With the pain is also classified itching and tingling. Interestingly, there is a substance called capsaicin that acts on pain receptors in the same way it does real damage. It has been found in things like jalapeno peppers, as mentioned above.
Kinesthetic Sense
The kinesthetic sense is based on receptor neurons of the muscles and joints that basically work on the mechanical principle of distortion. Some of these receptors are hair cells, while others are spindles start to fire when stretched.
Vestibular Sense
The vestibular sense tells you where "up", how is your body in relation to "up" and how your body is moving in space. The feelings are based on hair cells. In the inner ear, there is a special configuration of three semicircular canals around a central area. In the semicircular canals, the fluid motion when you turn causes gelatinous lumps called domes join each other, which causes the hair cells also join. The three channels are oriented approximately 90 degrees from each other, and that information makes you spin in three dimensions.
The vestibular sense is also connected to parts of the brain that tell you when it's time to throw. This is the cause of motion sickness.
If you tour a lot and then stop suddenly, the feeling lasts for a bit, and you think you're still spinning, but in the opposite direction. Your brain may try to compensate for this, and make you fall or at least feel dizzy.
You can also confuse these channels when you take a shower and hot and cold water enters your ear. Temperature changes can cause fluids to move and feel like they revolve, and then you may feel dizzy.
The two central areas of the body also have hair cells, hair cells are embedded in gelatinous lumps called the macula, which were taken in one direction or another, depending on if you're on your back, leaning to one side or another, or making pine. The inclination of the new hair cells send signals to the brain which interprets them accordingly.
Macula and dome
Ear (Hearing)
The ear is also a matter of hair cells. Surely you remember the basic structure of the ear: The external ear canal leads to the eardrum, a thin tissue stretching from the opening. Below the tympanum, there is a sequence of three tiny bones that amplify the vibrations of the eardrum. These end in another thin tissue that encloses the true organ of hearing, called cochlea. Is actually a tube, first folded in half, then turned in a spiral, and filled with fluid.
Section of the cochlea
Through this tube, there is a membrane that moves according to the patterns of waves in the fluid. Have hair cells growing under it, and these hair cells send messages to the brain wave patterns and changes it detects. This may sound pretty complicated, but the description is really very simplified.
Vision
The vision is different from all other senses. Involves receptor neurons that are sensitive to light. Light enters through the pupil and lens of the eye and is projected onto the dark surface of the eye called the retina. The retina is composed of, inter alia, receptor neurons called rods and cones.
Rods and cones
The rods are sensitive to a wide range of light, p. Eg tell us about "white." Contain rhodopsin, a substance that is sensitive to light. Note that a crucial part of this material is derived from vitamin A. Substances break when exposed to light and release a protein (opsin) which eventually releases a neurotransmitter to send messages to the brain ("no light"). After the released products are reconstructed in rhodopsin.
The cones are similar, but include a substance called iodopsina, which is sensitive to specific wavelengths, depending on pigments associated with them. One type of cone responds to red, one green, and one blue. Again, a protein (retinina) leads to the release of neurotransmitters, etc.
The rods are more sensitive than cones. This is why you see in black and white when there is not much light. Nocturnal animals tend to be color blind, that is, they do not have cones, for them the color is of little use while the high sensitivity if it is. Also, nocturnal animals usually have a bright background in the retina that reflects light back to the sticks called tapetum. It is usually made of tiny crystals. ! It is for this reason that cats and other animals reflect light in your eyes!
As with all the senses, vision is much more complicated, but for now we can serve know this.