The very mention of the word blood conjures up a hundred images. From the days of our pagan ancestors we have understood that blood is inextricably linked to life. Our history pages and wars are steeped in the spilling of it. The ancients considered it so powerful that they used it as the centre for their rituals. Vampires are reputed to drink it. They were not alone in their thirst. Ancient Romans, it is said, rushed to drink the blood of dying gladiators in the arena. Lady Macbeth famously wandered her chambers unable to wash the "dammed spot", the blood of the murdered King, from her hands.
Blood is our life force in more ways than one. In the middle ages drinking blood was thought to restore health and strength. It has been at times the 'sea' in which our soul resided. The habit of drawing blood was thought to release disease causing demons within us. It was once common practice to bleed people to take down fevers. Today we understand the role of blood a little better. That understanding has cleared up many of our superstitions. It has if anything, helped us come to terms with the vital role it plays in our lives.
Without blood our bodies would simply stop working. It runs through our systems delivering the essential ingredients for our survival and life. Our blood removes toxins and harmful poisons from our bodies. It carries oxygen from our lungs and removes carbon dioxide from our body tissue. Blood carries the nourishment from the food we eat to the parts of our bodies that need it. It carries hormones from our glands so we can grow and develop. Vitally, blood is our barrier against disease and illness. Natural Killer Cells in our blood float around looking for cancer cells and virus infected cells to destroy. They attack by devouring their target or melting away its skin. Any way we look at it, blood is an amazing substance.
Most of us only really think about our blood when we cut ourselves. Even then we swab or wipe the blood away, without giving it too much thought.
We know that soon enough, the blood will dry up. The cut will heal over and we can get on with our lives without too much worry. Beneath our complacency lies a complicated and fascinating world. It is a world that is alive and thriving with activity and hard work.
Your blood is alive. It contains living cells. These cells have a life cycle. They are born and eventually they will die. They require vitamins and minerals to keep them healthy and functioning. They work ceaselessly for your health and well being. Our blood cells are carried around our bodies by a straw coloured liquid called plasma. Liquid plasma is, if you like, the river that runs through us, carrying the vital forces and cells that keep us going.
Did you know that one drop of blood contains millions of red blood cells' These cells are constantly travelling through our bodies delivering oxygen and removing waste. Red cells are red because they contain Haemoglobin. Haemoglobin is a protein chemical that is bright red in colour. With the help of the element iron, it is a natural carrier of oxygen and carbon dioxide or CO2. A red blood cell typically lives for 120 days. While our blood is recycled, our bones are continually producing new red blood cells to replenish those that die.
As well as red cells, our blood is also made up of white cells. Being the mortal creatures that we are, we are often prone to germs and infections. Our bodies come under attack. When this happens white blood cells rush towards the invaders. Some white cells produce protective antibodies that overcome the germ invaders. Other white cells surround the bacteria and simply destroy it.
White cells are numerous and vibrant within our blood. There are five different types of white cell. There can be between 7,000 to 25,000 white cells in one drop of blood at any one time. Diseases that are hard to overcome try and fight back. Our bodies produce even more white cells to counteract this threat. If someone has a consistently high number of white cells, they may well have leukaemia, which is in effect a cancer of the blood. Neither red nor white blood cells would be able to function without the river of plasma that carries them to and from their destinations.
What though about that cut' In all probability it has stopped bleeding by now. Did you ever think how this occurred? Why don't we just bleed away' The truth is there is another vital substance in our blood that enables it to clot. These sticky substances are called Platelets. When we cut ourselves and when the blood is exposed to air it is platelets that go to work. They form and bond blocking the flow of blood. Platelets work in combination with calcium and Vitamin K. Without these things in our blood we would quite simply bleed to death. Instead our blood clots and a scab is formed on our skin. We not only can bleed externally but also internally. A bruise is evidence of internal bleeding. A bruise is a form of clot.
Perhaps our understanding of the nature of blood would not have advanced without the work of one Austrian, Dr Karl Landsteiner. In 1900 Landsteiner noticed that each of us has a particular blood group. Later he was awarded the Nobel Prize for his work and his team's discoveries. Humans had tried blood transfusions for centuries not only from each other but even from animals. These experiments met with mixed success until Landsteiner's discovery.
Landsteiner observed that there were two distinct chemical molecules present on the surface of red blood cells. He labelled the first Type A and the second, naturally enough, Type B. If the cells, as some did, had no molecule, these he labelled it Type O. If a cell had both molecules he labelled it AB. Blood transfusions became far more successful as each type of blood could be matched to its owner and donor. Today we are all familiar with the fact that we have different blood groups. As a result in an emergency it is entirely possible for you to receive exactly the right type of blood.
In a further development, scientists who studied the similarities between Rhesus monkeys and the human anatomy made a discovery. They noticed that in addition to our blood types we also carry an extra protein. The presence of this protein is now known as Rhesus positive. The absence of the same protein, Rhesus negative.
Our blood is nothing less than the fluid of life. It feeds us, restores us and fights illness on our behalf. The donation of blood and blood transfusions have becomes a vital part of our medical encyclopaedia. Understandably perhaps, the sight of our blood never ceases to amaze and even frighten us. The sight of the blood of others holds a morbid fascination for us.
Recently the advent of HIV/AIDS and other blood disorders have brought us to new levels of understanding. We now know how vital and important it is that the study of this most precious substance continues. We owe our blood a lot. One thing has never changed in our fascination for this mystery fluid. That is our realisation that it is life's precious commodity, and that we should never spill, if we can help it, even one single drop.
Sources used in this speech and related information
Blood Facts - Blood Book, Blood information for Life.
Kill or Cure: Blood
All about Blood