The surface area of the human lungs is approximately 70 square meters, which is roughly the size of a tennis court.
The human body contains enough iron to make a 3-inch nail.
Humans are the only animals that shed tears in response to emotional stress.
The human brain can hold the equivalent of 2.5 million gigabytes of digital memory.
The human heart pumps about 2,000 gallons of blood every day.
The average person will produce enough saliva in their lifetime to fill two swimming pools.
The liver is the only organ in the human body that can regenerate itself.
The surface area of the human skin is approximately 20 square feet.
The human body contains enough carbon to fill 9,000 pencils.
The human eye can distinguish about 10 million different colors.
The human body contains enough water to fill a 10-gallon tank.