Yawns are more contagious among people with closer relationships.
163
When you take a step, you are using up to 200 muscles.
886
It takes about 20 seconds for a red blood cell to circle the whole body.
102
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
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
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
Chewing gum boosts your brain power.
285