by J. Bruce Neill, Ph.D
Dr. Neill is the Director of Education at Sanibel Sea School. Part of the SCCF (Sanibel-Captiva Conservation Foundation) Family, Sanibel Sea School’s mission is to improve the ocean’s future, one person at a time.
Let me start with a small moment of reflective joy in a trying time. Life is miraculous. We are so very fortunate in so many ways. That we have the luxury to write, read, and ponder this musing is a gift we should all be grateful for, and spread with kindness.
The human body is a highly complex set of systems that carry out many amazing functions. The physical building blocks of living things are cells, and most cells have a fairly similar design that is somewhat consistent among different species of animals. However, each individual’s cells have a unique signature created by combinations of proteins embedded in the external cellular membrane.
I suspect we’re all aware that individual cells can be identified by DNA analysis, but that’s not what I am referring to here. The personal cellular fingerprint I am describing is on the outside surface of the cell. So, all of the cells in Bruce’s body have a similar (and nearly unique) external chemical composition, which differs from that of (nearly) every other individual.
This is relevant to our discussion of viruses because almost all creatures have a system dedicated to detecting and destroying foreign cells or objects inside our bodies. The advantage of such a system is protection: most foreign cells or objects (think a splinter) that don’t belong to us are likely neither friendly nor healthy.
But, in order to detect foreign cells, our bodies must first differentiate foreign cells from ‘self’ cells. The network of cells that accomplishes this is called the immune system, which constantly monitors every cell in our body. When the immune system discovers non-self-cells, it musters a defensive counter attack to rid our body from the invading hoards. This counter attack is called an immune response, and in immunological terms, the foreign cell or body is known as an antigen.
The average human body is composed of 35 trillion cells, all constantly monitored by the immune system to assure they belong. There are approximately 7.5 billion people on Earth, so the cellular population of our body is about 4,500 times larger than the human population, monitored constantly. That’s a whole lot going on every second of every day in our bodies.
When foreign cells or bodies are identified, a generalized immune response is usually initiated. The goal of such a response it to make our entire body, or any localized part thereof (again, think of a splinter) less hospitable to foreign cells.
One of the physical aspects of an immune response is a cascade of reactions that ultimately increases body temperature—either locally, near the site of a foreign object, or globally, throughout the whole body. An increased overall body temperature is known as a fever.
Another facet of an immune response is to help flush particles out of our body. Our capillaries (the tiniest of tubes that carry blood) expand and become leakier; the blood cells don’t leak out, but plasma (the water content of blood) does. The leaked fluid manifests either as a runny nose, watery eyes, or localized swelling.
The first written description of human immune response characteristics is attributed to the Roman scientist Aulus Cornelius Celsus around 30 BCE. We are only a small part of history—folks have pondered how the human body works for a long, long time.
So, breathe fresh air, get some exercise and let the wonders of our natural world ease your tension and anxieties. This will pass, and we will have a better future because of what we share (excluding the Coronavirus).
Spread joy and love in every way, in every moment that you can.
Wash your hands and face: right now. Get up and do it, then smile.