A View From My Window | The World Beneath Our Skin

Fall is such a beautiful time for scenery

Looking out my window, things seem reasonably peaceful. You would never suspect that I am sitting here with a defence force on active duty. Border patrols, training centres, checkpoints, experienced troops—all going about their business while I go about mine.

Have you ever stopped to think about what keeps you from becoming someone else’s lunch? I don’t mean the bear in the woods. I mean the microscopic troublemakers that would find parts of you a very comfortable place to settle down and raise a family.

They may be small, but so are the troops keeping them in check. And those troops are on duty while you sleep, while you shop, and while you stand in the kitchen wondering what you came in for.

You may have forgotten your mission. Fortunately, they haven’t forgotten theirs.

Meet your immune system.

We don’t usually think of our skin as part of our immune system, but protection begins there. Germs may land on us, but getting inside is another matter. Our skin helps block their entry, mucus traps them, and tears and saliva contain enzymes that damage certain bacteria. Even a good sneeze helps show some of them the door.  Of course, not every microbe is a troublemaker. Many live quite happily on our skin and in our gut, helping with digestion and keeping harmful germs from taking over. Some of the residents actually help look after the place.

But suppose an intruder gets past the walls of the perimeter.  There is a whole army waiting inside. The bone marrow is the recruiting centre, producing new immune cells. Some recruits head to the thymus for training, where they learn to recognise the body’s own cells—the ones carrying the familiar “part of me” identification—and to leave them alone.

The lymph nodes are checkpoints where immune cells inspect what arrives from nearby tissues, while the spleen keeps watch over the blood. Different white blood cells have different duties: some swallow invaders, some destroy infected cells, and others coordinate the response. Antibodies recognise particular intruders and can flag them for attention or block their entry into cells. And there are veterans on the team—memory cells that recognise an old enemy and help organise a quicker response. No need to start the briefing from scratch!

Quite an operation to be running while we are deciding what to have for breakfast.

What amazes me is that this whole force is on duty day and night, and most of us hardly give it a thought.  We tend to notice the aching knee, the unsettled stomach, or the face in the mirror that looks a little more tired than we would like. The quiet work that allows us to carry on gets far less attention.

Perhaps it deserves a little more.

Of course, keeping this defence force supplied is where we come in. We make sure the supplies arrive, and the troops get some rest. A nourishing meal, a walk in the fresh air, a decent night’s sleep—ordinary things that take on new meaning when we think about who we are supporting. We don’t have to turn caring for ourselves into another demanding assignment, but we can do a little more to look after those who are looking after us.

There is also something deeply reassuring in knowing that so many different parts of us work together. Each has its place. Each contributes something the others need.

And what an example of teamwork. The newest recruit, the border patrol, the veterans who remember an old enemy—all depend on one another. No one unit can keep us safe on its own. Their strength lies in how well they work together. There may be a lesson in that for the rest of us.

Looking out my window, I can’t see any of these patrols or training centres. There is no fanfare when an intruder is stopped, no announcement when another small crisis is averted. I just

get to go on with my day.

Perhaps that is the finest tribute to how well they do their work.

So tonight, when I turn out the light, I might spare a thought for those still on duty. “Good night, everyone. Thank you for your service. I’ll see that breakfast arrives.”