It takes about 20 seconds for a red blood cell to circle the whole body.
102
Every human spent about half an hour as a single cell.
144
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
Your thumb is about the same size as your nose.
124
Obsessive nose picking is called Rhinotillexomania.
101
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Shark corneas are used in eye transplants and shark bone marrow can be used to graft human bones.
132