Crawl beneath your own skin for a scientific look at the inner-workings of the human body. The latest research in biology, anatomy and physiology is combined with eye-popping imagery to explore everything from puberty to food poisoning – from the inside out.

Body Snatchers
Go inside the bodies of two women whose natural systems each must deal with foreign organisms trying to control its host: a flu virus and a growing fetus. The body's reaction to and changes from each "invader" are truly remarkable.

Breaking Down
An 11-year-old girl with a broken arm and an 87-year-old man vividly illustrate the differences in the way a young body heals itself and the way an old one struggles. See how the body repairs itself after an injury – and how these very repairs lead to our eventual demise.

The Beast Within
Unravel the mysteries of the two most important organs in the human body – the heart and the brain. First, take a look at how frail the human heart is as an emergency team frantically works to save a heart-attack victim. Then, meet a man whose brain cannot correctly transmit signals – because he's consumed too much alcohol.

Teen Dreams
Follow the flow of hormones – from pituitary glands on through the bloodstream – of two young teens, Darren and Natalie, as the dramatic effects of puberty unfold. The month culminates with Natalie's first menstruation and a weekend party – during which Darren's body seemingly does everything it can to ruin his chances with Natalie.

Crash
A husband and wife are critically injured in a car crash – he's unconscious and suffers from epileptic fits; she has a punctured lung and is left with a blood clot. See how the force of impact damages the delicate internal structures of their bodies – and how doctors work to repair their injuries.

Spreading Menace
While eating at a friend's birthday party, Mike ingests Salmonella bacteria and falls ill. Follow the trail of the invading microbes through the digestive system – from the mouth to the lower intestine – and examine the body's formidable arsenal of weapons designed to combat these tiny terrors.

Out of Control
It's estimated that one out of four people suffer from some form of allergy – but few reactions are as severe as Phoebe's, a young woman who has been stung by a jellyfish. As her immune system launches a full-scale assault on the toxins, travel through her bloodstream to examine the plan of attack.

Take a provocative look at the varied and complex processes that go on inside all of us – from the way our natural defense systems treat injuries to the everyday functions our bodies carry out.