Here’s an easy question: “How many senses does the average person have?” The majority of people would answer this question with the same number - five. Unfortunately, most people are just plain wrong - as any good doctor, or school-kid with an interest in basic human biology, would now be able to tell you. The reason for this is that on top of the five “main” senses -sight, hearing, taste, touch and smell- there is a vast array of other senses including, but not limited to, equilibrioception, or our sense of balance, which the majority of us rely on to a greater extent than we rely on our sense of touch, taste or smell; this particular sense even has its own unique receptors found in the form of the semi-circular canals located within the inner ear.
At this point some people will most likely be thinking - all right smart arse, so what’s the real answer? Well, I’m afraid I’m going to have to disappoint. The truth is that no one can say for certain how many senses there really are, not least because no-one seems to have bothered to work out exactly what is meant by a “sense” - for example, few species are able to recognise themselves in a mirror, is this a special “sense” of ours, or, what about the “sense” of hunger?, should we count this?, after all, blood sugar levels are monitored by special receptors and without a “sense” of hunger we would be in danger of starving to death.
Whilst I am on the subject of senses this seems like as good a time as any to dispel of a particularly common misconception about our sense of taste. Many older biology textbooks still feature diagrams known as “tongue maps” which are claim to show which sections of the tongue detect which tastes. These tongue maps are, to put it mildly, complete and utter bollocks. The taste receptors for the various different tastes are not grouped together in this way but are in fact distributed evenly across the surface of the tongue (i.e. tongue maps are total nonsense).