The average adult body contains between 5 and 5½ liters of blood and approximately 10 liters of interstitial fluid. This forms approximately 60% of the human body. This ratio varies from 75% in a newborn infant to 45% in an obese person.
With the 60,000 miles of blood vessels inside the average human body, you could circumnavigate Earth two and a half times

For every pound of fat or muscle gained, your body creates seven miles of new blood vessels.
Your body produces 25 million new cells each second. Every 13 seconds, you produce more cells than there are people in the United States.
Your stomach manufactures a new lining every three days to avoid digesting itself. As a part of the digestive process, your stomach secretes hydrochloric acid, which is very corrosive.

Your brain uses 20% of the total oxygen and blood in your body. In a lifetime, your brain's long-term memory can hold as many as (1 million billion) bits of information.
Nerve impulses travel to and from the brain at speeds of up to 250 miles per hour, faster than a Formula 1 race car.

The human eye can distinguish 10 million different colors. The focusing muscles in your eyes move around 100,000 times a day. If the human eye was a digital camera, it would have 576 megapixels.
The human body contains a huge number of bacteria, archaea and methanogens. Within three days of death, the enzymes that used to digest your food, begin to eat you.

Scientists discovered the hearing sense for the embryo develops in the mothers’ womb before the sense of sight. This is compatible to the sequence in the Quranic verse 32:9.

That is the Knower of the unseen and the witnessed, the Exalted in Might, the Merciful. Who perfected everything which He created and began the creation of man from clay. Then He made his posterity out of the extract of a liquid disdained. Then He proportioned him and breathed into him from His [created] soul and made for you hearing and vision and hearts; little are you grateful.
"And the Lord God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul". Genesis, 2:7