Your thumb is about the same size as your nose.
124
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
The average sperm cell swims at 8 inches per hour.
76
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
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