Breath of Life
Most organisms can go without food and water for days, but can't subsist without oxygen for more than a few minutes. See how vital oxygen is absorbed from the air and transferred to the blood in the lungs' huge air/blood interface. Amazing in-the-body footage shows how red blood cells carry oxygen, where the oxygen goes and how it is used.

Skin
It's the body's largest organ – the average adult's skin weighs about seven pounds – and yet we shed it every month. Learn how your skin contributes to hair growth and the production of finger and toenails. Go inside the body to see the journey of a sweat droplet – from its birth in the sweat glands to its departure via one of the trillions of pores on your skin.

The Food Machine
Take a trip through the alimentary canal to see what happens to the food we eat. Start in the mouth, where powerful teeth initiate the digestive process. Then, hitch a ride on the saliva train for a journey through the esophagus. Dodge deadly acid attacks in the stomach and further breakdowns in the small intestine. And finally, be eliminated as solid waste. It's a dirty job, but everyone's got to do it.

Taste and Smell
Travel through the olfactory tract to learn why taste and smell are irrevocably linked. Visit a wine tasting, where receptors on the tongue and in the nose enable visitors to distinguish between a myriad of flavors. Discover how even the most underwhelming scent can evoke a powerful memory and understand the effects of hay fever and other allergies.

Visual Reality
The human eye can outperform the best cameras, yet can easily be fooled by a simple optical illusion. Become familiar with the different parts of our incredible cameras – the cornea, iris and lens – and find out how we process images using rods and cones to distinguish contrast and color.

Defend and Repair
Learn all about the body's immune system and go face-to-face with mankind's greatest enemy – germs. Each of us has more than two pounds of bacteria in our intestines, but how exactly do these creepy critters cause disease? See first-hand how the body heals torn skin, mends broken bones and fights infection.

Sex
Witness the miracle of life – on a microscopic level. Amazing footage shows how the ovaries produce eggs and how sperm is created. After the egg is fertilized, track the growth of an actual fetus in the womb – from the development of its tiny organs to its eventual, miraculous birth.

The Human Pump
Over a lifetime, the human heart will beat two-and-a-half billion times and pump some 50 million gallons of blood. With the help of arteries, capillaries and veins, it delivers blood to all corners of the body. Learn what blood pressure reveals and why blood is truly thicker than water. And discover how blood clots – or, in the case of hemophiliacs, how it doesn't.

Now Hear This
The ear is the only sense organ that does two completely unrelated jobs: it allows us to hear and keeps us on sound footing. Go from the eardrum and cochlea – the auditory heart of the ear – to the semi-circular canals that control balance. And, learn why your hearing and musical pitch might be better than your neighbor's – and how you can tell.

The Brain
It only weighs three pounds, but it's more powerful than any computer on earth. Discover how our nerves relay messages around the body and how reflexes originate in the lower brain. Visit the location centers for sight, hearing and speech, and see how functions like memory are distributed throughout the brain.