Newsletter #10 - Wondrous World Within

Hi friends, Fantasy/Sci-Fi/Horror author Paul James Keyes back with another newsletter!

The last newsletter was all about Fantasy tropes and how I use them to subvert reader expectations. [LINK TO NEWSLETTER 9 - SMASHING FANTASY TROPES] Today, I couldn’t resist writing about a topic I hinted at a couple of letters ago—the second most complicated biological system known to mankind: The human immune system.


When you sustain an injury, like a cut to the hand, a lot of really cool and fascinating things happen inside of you. First, the cut introduced possible bacteria and viruses into the surrounding tissue and bloodstream. Your immune system is always on the lookout for threats. It creates hundreds of billions of new cells inside of you each day that roam through your lymphatic system.

Your cells, under attack by a horde of bacteria release chemicals as an alarm signal to your immune system, which quickly responds by sending little soldiers to fight on your behalf. Our bodies really are ecosystems. An invasive species can kill us, unless our immune cells can stop them from spreading.

Macrophages show up first. They are your warrior cells. They are large compared to normal cells and bacteria. They reach out with long tentacle-like arms, grab bacteria, and consume them whole. They can eat about 100 bacteria before they get full and go into a digestive state. If there is too much bacteria, they get overwhelmed, and the next phase of the immune system kicks in.

Next, neutrophils pick up the macrophages’ signals. You only have a few hundred thousand of these at any one time, which really isn’t that many, but the reason for their short supply is because of how they work: They shoot chemicals at the bacteria, and some even explode—and this does damage to your cells as well as the bacteria. They are indiscriminate killing machines that have one goal, eradicate all the bacteria at any cost. Neutrophils only live for a few days before ending themselves, with or without conflict.

As the battle ensues, your blood vessels open up and flood the infected area with fluid. This causes inflammation, but lays the ground for the battle ahead. The fluid is filled with compliment proteins, which overwhelm bacteria and rip holes in them. At this point, if your body detects that the battle is not going in its favor, the next stage of your immune response begins.

Something called dendritic cells go to the battlefield, collect some bacteria, rip them apart inside of themselves and then decorates their outsides with pieces of dead bacteria. The dendritic cell then travel back to the super highway of your lymphatic system and go on a search for a T cell that has the perfect weapon to fight against the bacteria.

Your T cells are probably the most fascinating part of the whole system. There are up to a billion of them inside of you, and each one is built a little bit different from the rest.  Each has its own set of weapons that would be good for fighting a specific shape of bacteria. Each bacteria that exists now or could ever form has a matching T cell that could kill it—a very complicated game of rock, paper, scissors—but first, your dendritic cell must find it! It rubs the dead bacteria parts on every T cell it passes until, usually after a few hours, it finds one that can fight against the invading bacteria.

Once found, the dendritic cell coaxes the T cell into replicating over and over again until there are enough to send to the battlefield as reinforcements. As soon as they show up, chemical signals given off by the T cells reinvigorate the macrophages that are still alive, and together they ravage the bacterial forces.

If that doesn’t do the trick, your dendritic cells continue working to find more help in the form of the perfect B cell that works as a factory to produce the right antibodies to fight the bacteria. It takes about a week to get your B cell antibody factories up and running, but once they do, you tend to always have a supply of those antibodies on hand in case of reinfection by the same strain of bacteria in the future. Your T cells do the same thing, some of them hanging around as memory cells in case their weapons are needed again.

There’s certain a lot to the human immune system. Here’s a video that talks about the same thing as this newsletter with a British narrator and a nifty cartoon depiction of what goes on when you’re injured:

The micro world is pretty dang cool.

Next time I’ll cover my views on what humanity is to the Earth. Are we a virus, or are we its immune system? The answer depends on your perspective.

Until then, stay safe out there!

Freebie: Into the Beyond - Part 1: Fated - A Fantasy Horror Series



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