Human Body Facts
Human Body Facts
Blood Facts for Kids
: Blood (Bodily fluid)
: Throughout the body
: Circulatory system
: Transport nutrients, oxygen and remove waste
: Plasma, red blood cells, white blood cells and platelets
: 10 to 11 pints (average adult human)
25 Blood Facts for Kids
Blood is a fluid that is part of the human cardiovascular system.
Blood is transported throughout the body by the heart via blood vessels (arteries, capillaries and veins).
Human blood is red and gets its color from the hemoglobin protein.
The average human adult has around 10 to 11 pints of blood in their body.
The blood volume in an average human adult will be about 7% of their body weight.
Blood carries and delivers important substances (nutrients and oxygen) to cells and it remove wastes (metabolic waste and carbon dioxide) from those same cells.
Human blood is made up of plasma, red blood cells, white blood cells and platelets.
The composition of human blood is 54.3% plasma, 45% red blood cells and 0.7% white blood cells.
Platelets react to damage to the body and form blood clots to stop bleeding.
A blood platelet can live between 9 to 12 days in the human body.
White blood cells protect and defend the body from foreign invaders, like viruses, bacteria and parasites.
There are many different types of white blood cells in human blood, like basophils, eosinophils, granulocytes, lymphocytes, monocytes and neutrophils.
Some of the white blood cells types in human blood only live for a few hours, while others can live for years.
Red blood cells deliver oxygen to tissues throughout the body.
An ounce of blood contains around 150 billion red blood cells.
A human body can create about 17 million red blood cells per second.
A red blood cell can live for up to 120 days in the human body.
The human body creates blood cells in bone marrow.
Humans have different blood types, like A, B, AB or O.
Human blood types are classified using the ABO blood group system.
The ABO blood types in humans was discovered in 1901 by Karl Landsteiner.
The rarest blood type in the United States is AB negative (AB-), it’s estimated only 1% of the population has it.
The most common blood type in the United States is O, it’s estimated 37% of the population has it.
You can donate blood and blood plasma which will be used to save a life.
Every time you donate blood you can potentially save up to three lives.
More Human Body Facts
Circulatory System Facts
Digestive System Facts
Immune System Facts
Skeletal System Facts
Pictures of Blood
A diagram showing all the different components of human blood.
A picture of blood bags filled by people who donated blood.
A picture of plasma bags filled by people who donated plasma.
Credit: Denios Balibouse / Reuters
Additional Resources on Human Blood
What is Blood?
– Learn more about blood and what it is on the OneBlood website.
The Basics About Blood
– Discover the basic facts about blood on the American Society of Hematology website.
Facts about Blood Types
– Read about blood types, what they are and how many different blood types there are.
Blood - Britannica
– Find more cool blood facts and information on the Britannica website.