The human body is a wondrous collection of interconnected systems that allow us to convert energy, perform tasks, and even heal. But how can the body heal? The body has a complex system of automatic systems that heal and repair damage unbidden by our conscious thought. This autonomous ability to heal is something referred to as innate intelligence. Our bodies are literally programmed to heal with no active participation on our part. It is only what we do to our bodies that enhances or harms this process.
A cut or tear in a blood vessel will start a series of events in action. Vasoconstriction is the result of the blood vessels leading to the wound tightening to reduce the flow of blood. Platelets react to enzymes coming from the torn blood vessel and quickly amass at the sight of the injury. The platelets stick and clump to each other and cling to the sides of the tear, creating a plug. The clotting proteins (fibrin) form a net that holds the platelets in place, forming a more permanent seal. Depending on the severity of the injury, coagulation of the blood will make the bleeding stop after a few seconds or minutes. Traumatic injuries often can’t stop the wound from bleeding since the wound is simply too big.
Fighting infection is the next step, as the constricted blood vessels now relax to allow white blood cells to arrive on scene, engulfing and destroying and germs that may have come in through the injury.
Finally, the body heals and rebuilds. Fibroblast cells gather at the injury and form collagen, eventually filling in the wound under the scab with new skin cells and creating capillaries to bring oxygen-rich blood to the injury site. Over the next couple of weeks, the skin along the edges of the wound thickens and stretches to the center of the injury, meeting up with the skin from the other side to form a scar. This scar will eventually fade over several years as more collagen is added; it is about 80 percent as strong as the original skin.
But healing wounds isn’t all the blood does; it also acts as the primary internal transportation system for the body, delivering nutrients, proteins, hormones, medications and other substances throughout the body. It also ferries waste products like carbon dioxide and toxins from the body. It is also an incredibly important part of the immune system for fighting off disease.
The blood carries antibodies, the body’s system for fighting off foreign bodies, infections parasites, bacteria, microbes, and toxins. Antibodies are specialized proteins that seek out and mark for destruction anything they don’t think should be in the body. This is how the body fights off diseases and infections, with antibodies travelling to throughout the body carried by the blood stream on a constant search and destroy mission.
Some bacteria and viruses are eliminated by other components of the immune system. A bacterium that enters through food is often destroyed by stomach acid. Things that try to enter our bodies through the air we breathe have to make it past an array of defenses before making it to our bloodstream, including the hair in our nose, mucus and other biological defenses.
Blood doesn’t do the job alone – it has a host of organs helping it along including the thymus (where T-Cells are generated and go to die when they’re faulty), the spleen (filters the blood looking for foreign cells and replaces old red blood cells), the lymphatic system (which filters fluid to and from cells, delivering nutrients from the blood, and filtering out waste products including bacteria when the body has an infection), bone marrow (produces red and white blood cells), white blood cells (a collection of different cells that work together to destroy bacteria and viruses), antibodies (bind themselves to viruses, bacteria, venom and toxins to stop their absorption through cell walls and signal to the complement system that the bad cells must be removed), and the complement system (a series of free floating proteins in the blood stream manufactured by the liver that cause lysing or bursting of cells and signal to the phagocytes when cells need to be removed). Additional pieces to the immune system puzzle include hormones, Tumor Necrosis Factor (TNF), and interferon.