|MadSci Network: Medicine|
Good question Jeanine! You probably notice that your eyes water when you get something in them-like an eyelash or a speck of dirt. Tears are our bodies' way of getting rid of this foreign object in our eye before it can scratch or otherwise harm the surface of the eye. But if you think about it, our nose and ears do the same thing. When we sneeze (or at least when I sneeze), we get a runny nose afterwards. This is another way for our body to get rid of dust or pepper or whatever is bothering our noses out of our bodies. Both the sneezing part and the runny nose part are important in this process. Ears don't water exactly, but they do make wax. And this wax helps keep out dirt and water and other things that could clog our ear canal. So what you've seen here for eyes, nose and ears, is that watering (or wax) are important to get bad things out of our bodies, or to protect our bodies from these bad things in the first place. The question about our mouths watering is a little different. When our mouths water, it's usually in response to smelling or seeing something good to eat (for me it's definitely chocolate chip cookies). The "water" is actually saliva. And saliva plays an important role in digestion. First it helps keep the food moist while chewing. And secondly it contains enzymes which start the digestion process, even before the food gets to our stomachs. We call this mouth watering phenomenon 'conditioning' which is just a fancy way to say that if we see food it probably means we will be able to eat that food soon and our body is just getting ready to digest it. Hope this is helpful! Please let me know if you want more information on any of these subjects. -Sarah Tegen firstname.lastname@example.org
Try the links in the MadSci Library for more information on Medicine.