Each 2.54 square centimetre (a square inch) of human skin ... population has high blood pressure. The sensation of pins and needles is caused by an impairment of blood circulation.

George Washington died after his physician treated his sore throat with bloodletting, but don't let that stop you from ...

This short film offers a look at respiration and a tour around the circulatory system and digestive system in the human body, through blood vessels and into mitochondria. There is a detailed ...

For nine months, you were enveloped in the warm, comfortable world of your mother's womb. Your every need was taken care of. The placenta supplied you with oxygen from your mother's blood, so your ...