Mucus, Keratin, And Other Biological Barriers That Are Essential For Cycling, And FitOldDog’s Shopping Cart Metaphor For Life

“If it is love that makes the world go round,

it is surely mucus that permits it’s translational motion.”

I read this ‘Love Poem’ in a book on mucus years ago. Written by an engineer. Go figure!

Hi folks,

Remember to do the work needed to return your 'shopping carts,' be they for the grocery store or your body.

My friend Stacey asked me the other day, “What do you think about while you ride your bike?” I was riding an easy 60-mile spin this beautiful morning, between breakfast and a short swim (then FOOOOOOD!), and I found myself thinking about what I think about whilst I’m cycling, and then I started to think about shopping carts. In fact, I came up with a whole shopping cart metaphor for Biological barriers and their maintenance, which led me to think about which barriers are key during cycling. So, I guess the answer to Stacey’s question is, “Whatever weird stuff comes into my mind.”

I’ll come to shopping carts in a minute, but first let’s deal with the obvious. Keratin is a key component of your skin, making it strong enough to cope with local stresses, like my ass rubbing my bike saddle for hours on end (best part of an Ironman race = getting off of the bike saddle!). Mucus is critical for the protection of your eyes, as mucus glycoproteins are present as a lubricant in tears that, combined with the windscreen wiper effects of your eyelids, continually clear debris your visual field. Mucus is equally important in your nose and lower respiratory tract as a component of the mucociliary apparatus. This evolutionarily ancient system clears inhaled particles and reactive gases (to some extent) deposited in your airways. In fact, about it 30 years ago, because I had such difficulty explaining the dynamic nature of this system to other scientists (and the people who gave me money to do the research) who had never seen it in action, I made a movie with my friends and colleagues at The Chemical Industry Institute of Toxicology. Here it is (having traveled from 16 mm movie film, to VHS, to DVD (lost for 2 years), to AVI, to FitOldDog’s YouTube account. It lasts about 10 minutes, and I still think that it is pretty good, considering the technology of the day. OK! This is what is going on up your nose all the time, thank goodness.

Remember, “The solution to pollution is dilution,” which is exactly what happens with your tears and the continual river of mucus flowing through your respiratory, gastrointestinal, and reproductive tracts. In fact, there is a mucociliary apparatus in your ears that keeps your Eustachian tubes clear. Mucus is everywhere. The oceans are lined by mucus, which is even used for fishing nets by certain organisms. Mucus is magic, but what about shopping carts?

Your body is like a complex factory that makes lots of things out of lots of other things, and if some of these things mix too fast, or at all, mayhem will result. So a whole system of pipes and barriers exists in your body to keep everything in its rightful place. For instance, each of your 10 to 20 trillion cells accumulates potassium while pumping out sodium. Lots of potassium inside your cells. Lots of sodium outside your cells, just like in the seawater from whence we come (interesting happenstance?). The cell membrane is a barrier that keeps these things as they should be, but not without a lot of work. Pumps in cell membranes bring potassium in and take sodium out, using energy in the form of ATP (I talked about that before). And this is where shopping carts come in.

If you go to a large grocery store you will find lots of shopping carts – if you don’t, you probably won’t come back. People take their shopping carts with their stuff out to their cars, some return the carts to the store, some return them to the cart location, and some just leave them wherever. Some people even push their shopping carts home and leave them there. You see these abandoned shopping carts rusting away all over America. They never return to the store. The guy who goes out to the parking lot to bring the carts back to the store is just like ATP, the energy needed to put things back where they should be. The lost carts represent the inevitable loss due to ‘entropy,’ the world is just like that (and so are some weird people!). The system just keeps running, but if the shopping cart guy doesn’t turn up you have chaos.

In the body, the shopping cart guy, or the money they pay him/her, is equivalent to ATP, and without it the potassium that leaks out of your cells and the sodium that leaks in, won’t be put back where they belong, in which case you wouldn’t have action potentials in your brain and you wouldn’t be able to think about anything, whether you are on your bike or not. And that is how the world goes round – constant work to maintain your barriers and keep things on either side of them as they should be.

So remember to put your shopping cart back!

-k @FitOldDog