07/02/2023
Fascinating Facts About Blood
Your blood brings oxygen and nutrients to your organs and tissues. But there are many other important functions of blood that aren’t as well known. Take a look at some fun facts about blood:
Why is Blood Red?
The amount of iron and oxygen in your blood determines the hue of red. Blood leaving the heart has more oxygen and is a brighter red. Blood returning to the heart appears darker since it contains less oxygen.
Most animals also have red blood. But some crustaceans have blood with a high level of copper instead of iron. Copper mixes with oxygen and gives blood a blue color. Some lizards even have green blood.
How Much Blood Does Your Body Hold?
The exact amount varies according to a person's size. Blood makes up approximately eight percent of your body weight.
The average man has about 12 pints of blood compared to about 9 pints for an average woman.
What Are Blood Types?
Everybody has the same components in their blood—the red cells, white cells, platelets, and plasma. But not everyone’s blood is exactly the same.
Blood types are based on the presence or absence of specific antigens or antibodies on the surfaces of the red blood cells. An antigen is a substance that can cause an immune system response.
A and B are the two most common antigens in human blood. The presence of A or B, or both, determine whether a person has an A type, B type, or AB type blood. People with neither antigen have O type blood.
Type O is the most common blood type in the world.
Another antigen is a protein called the Rhesus (Rh) factor. People with this protein are considered Rh-positive, and those that lack it are Rh-negative.
There are actually there are now 28 other, rarer types, often named after the person who discovered them. These rarer types are identified by the presence of a particular group of antigens.
If a person requires a blood transfusion, the blood type they are given must be a compatible type or their immune system may reject it. This can be life-threatening.
Most people can receive type O blood safely, regardless of their blood type. This is why most blood donation clinics are in need of type O blood.
What About Blood Donation?
Donating blood can save lives. For those who are unsure about donating, consider the facts below:
• Around five million people in the U.S. receive blood each year.
• Someone needs blood about every two seconds.
• Typically, a person will donate just one pint of blood at a time.
• Most people don’t develop side effects from donating.
10 More Fun Facts About Blood
• Blood contains a yellow liquid called blood plasma.
• Blood plasma is made up of 90 percent water, but also consists of hormones, glucose, proteins, gases, electrolytes, and nutrients.
• An adult has about 60,000 miles (100,000 kilometers) of blood vessels.
• Granulocytes are a special type of white blood cell that roll along blood vessel walls in search of bacteria. If they find any harmful bacteria, granulocytes will engulf and destroy them.
• Humans can survive with an artificial heart but there is no such thing as artificial blood.
• The only place blood isn’t found in human body is the cornea in the eye. The cornea is capable of directly extracting oxygen from air.
• Your kidneys filter more than 400 gallons of blood every day.
• Each second nearly two million red blood cells in an adult human body die.
• One pint of blood can save three lives.
• The first successful blood transfusion took place in the 1660s. It was performed in dogs, not humans.
