So...think about the last time you went to the bathroom, was it because you felt an urge to purge or you just went for no reason. Most likely the sensors in your rectum or bladder noted a certain pressure being exerted upon those organs and got you off your duff to go expel the waste your body had accumulated. This is the purge sense, bet you never thought it was a sense but if you are like me i don't think you would ever want to be without it.
We all get hungry and thirsty and those senses are pretty self explanatory. You can’t go too long without having to eat or drink, if you did ignore these two you would certainly put your body at risk. Some of you may say Hey! These could be lumped under taste, but taste doesn't make you eat. Just tasting something is vastly different from tasting something because you are hungry or drinking something because you are dying of thirst. The hungry and thirst comes first before the taste and that usually stems from activity inside your body not your tongue.
The sense of pain is another sense that goes under a special label called nociception. Nociceptors detect mechanical, thermal or chemical changes above a set threshold and send signals along the spine to your brain. Without these wonderful nociceptors there would be nothing to tell you to stop inflicting pain to your body and nothing to notify you that you have pain in your body and you should probably start tending to it. The sense of pain saves you from yourself, something i think we can all relate to.
So look outside...today is a pretty hot day for those of us in the islands, most of us try to avoid being outside under the sun for prolonged periods of time. If we are outside we usually spend some time trying to cool off either in the ocean, a pool or under a hose. If not doing that we are not outside at all and are hiding inside a building with AC or fans or limin under a shade tree. Somehow we all try to cool down to keep our body temperature at a comfortable level. If we were in a cold climate we would be doing the opposite to warm up our bodies. Thermoception is another one of those senses we don’t think about as being a sense but if we didn’t have it we would probably do serious damage to our bodies if we couldn’t recognize excess temperature ranges.
Have you ever had that sense of toppling over but catching yourself in time and managing to maintain your balance? Well equilibrioception or the sense of balance is what keeps you standing upright whether you are standing still or moving. Three systems, the eyes, ears and the bodies sense of where it is in space operate together to keep you vertical. Without these you would have difficulty moving around and would have to be trained to overcome any lack of one of these three. The sense of balance helps us everyday as we navigate our world on two feet.
Knowing where your body is and what it is doing is also a sense. You always know what your body is doing in relation to itself unless you have some underlying kinesthetic deficit. Anything you do with your body like taking a piece of food and putting it in your mouth, or reaching over and picking something up or even driving involves the nervous system and its ability to keep your body functioning without actively watching it. Closing your eyes and putting your finger to your nose is a good demonstration of this sense. Your body knows how to find your nose without looking. It always knows where you are.
According to some of the things i have been reading we really have between 9 and 20 separate senses depending on which sense researcher you follow. Time, itchiness, internal perception, a host of touch and eye senses etc. are all considered respectable groups that deserve their own studies. Who knows maybe extra sensory perception will some day be listed among those for more serious consideration. Anyway if you are still stuck believing that we only have five senses maybe you don’t need to go to the bathroom and have toppled off your chair taking the computer with you.
See ya next week.