The Sixth Sense!

I had what I consider a great educational day today. My son and I discussed our five senses.  Then, we emailed the extended family and everyone joined in....I thought I'd share it with you.
I have long heard that humans have five senses.  Today, while talking to my son, I raised the question of a sixth sense. Does our innate ability to sense gravity via our inner ear constitute a 6th sense?  David and I think it does!  We have 6 senses through which we perceive the outside world. 

All the psych textbooks have it wrong! 

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 After some though, I realize that my inner ear can not only tell me which direction gravity is pulling, it can also sense acceleration (not speed).  It's got at least two ways of perceiving the outside world.

David then told me that many people can tell you when it's going to rain.  Our joints act as barometers.  Does that mean that we have a 7th sense with which we perceive the outside world?

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 You are right about balance and acceleration being an additional sense.  And that there are sensors in the joints.

There are actually more senses than even that in humans and many more in animals that humans don't have.  

----The one I'm most familiar with is the kinesthetic sense.  You know where each of your arms and legs is without looking.

----Dogs (and other animals) have a sense organ in the back of the roof of their mouths which is a chemical sense similar to taste and smell.  That's why dogs lick things....to get some molecules back to it's vomeronasal (sp?) organ.

----Bees and some birds can sense the Earth's magnetic field and use this to navigate.

----Some fish (such as in the super-dark deep sea) can sense electricity and use this to detect/locate prey.

Aristotle is credited with saying we have (only) 5 senses.  

---But there are many more and when it comes to counting it gets hard because what counts as a sense gets debatable.  For example, there is a sense called "nocioception" (pain reception).  But I think of this as part of the sense of touch.

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I learned about proprioception when my mother was having trouble with balance. Ruth

Here's something from Wikipedia:

Equilibrioception or sense of balance is one of the physiological senses. It helps prevent humans and animals from falling over when walking or standing still. Balance is the result of a number of body systems working together: the eyes (visual system), ears (vestibular system) and the body's sense of where it is in space (proprioception) ideally need to be intact. The vestibular system, the region of the inner ear where three semicircular canals converge, works with the visual system to keep objects in focus when the head is moving. This is called the vestibulo-ocular reflex (VOR). The balance system works with the visual and skeletal systems (the muscles and joints and their sensors) to maintain orientation or balance. Visual signals sent to the brain about the body's position in relation to its surroundings are processed by the brain and compared to information from the vestibular, visual and skeletal systems.

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