Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your body is creating and killing about 2.4 million red blood cells per second.
17
The human brain has the capacity to store everything that you experience.
4k
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13