What’s So Great About Blood Anyway?

Why is blood critical for life?

If need be you can have a machine breathe for you, clean out your kidneys, keep your heart pumping or even transmit audio waves into sounds your brain can hear. But you can’t have a machine make blood for you. Blood is extremely valuable. Every human has almost 5 litres of blood coursing through their bodies. It forms 7% of a human’s weight.

There are a number of functions only blood can carry out in your body. Here are the 6 most important.

1. Without blood, your body’s tissues asphyxiate.

They would literally die from lack of oxygen. The haemoglobin in the blood carries oxygen from the heart and lungs to your tissues. Once it’s delivered its oxygen payload it then collects the CO₂ exhaled by the lungs and carries to the heart to be turned into oxygen.

2. Without blood, your body’s cells would starve.

Your gut breaks down all the food you eat. The capillaries inside the gut absorb all the nutrients out of the food and send it through the portal vein to the liver. The liver then puts all those nutrients into the blood and sends it to all of the cells in your body.

3. Without blood, your body wouldn’t survive a paper cut.

Your blood is made up of plasma, platelets, red and white blood cells. And all 4 are vital. It’s the plasma that stops you from bleeding to death from a paper cut. There are factors in the plasma that cause it to clot, plugging small tears, keeping the pressure in the blood to remain constant. Obviously, if the wound is too large, the clotting can’t cope. A human shouldn’t lose more than 15 to 30% of their blood. After that it becomes life-threatening.

4. Without blood, your body wouldn’t be able to combat infections.

Your white blood cells contain the infection and your plasma defeats them with antibodies. When your system is overwhelmed antibiotics are needed to lend a helping hand.

5. Without blood, your organs wouldn’t function properly.

Your blood delivers the right hormones and signalling molecules to your organs. If you don’t have the hormones in your organs you end up with no energy and your organs start to malfunction.

6. Without blood, your internal thermometer won’t function.

Blood helps to regulate your body’s temperature, helping your gut to digest food and your skin to sweat.

Why is donating blood so important?

It takes the human body a long time to replace any blood that’s been lost. Plasma is replaced in approximately 24 hours but red blood cells are only replaced in about 4 to 6 weeks. Obviously, in an operation or emergency situation that kind of time isn’t available. In South Africa, 3000 plus pints of blood are needed every day to ensure base line limit of a safe and sufficient blood stock. The South African National Blood Service separates each pint of blood donated into plasma, platelets and red blood cells. This means your pint could save up to 3 lives.

Everyone knows donating blood is a good idea, but very few think about it until they need it themselves. It’s time to change that way of thinking. If everyone who was able donated blood every 2 to 3 months there would never be a shortage. And a shortage of blood is never a good idea.

When did you last donate blood?