How do they do it? Penguins standing on ice, not only for days, but their whole lives! And their feet don’t hurt like ours would. It has something to do with blood and an amazing twist that penguins have developed.

Usually, the 160,000 kilometers of blood vessels in your body work incredibly smoothly. However, the forces of age, weight gain, and gravity can conspire to cause lumpy varicose veins.

Today on SciShow news, dead person wisdom is helping enrich our understanding of the natural world - how did Vikings manage to be such awesome navigators? And is heart disease inherent in human beings? Scientists think mummies may have...

How do they do it? Penguins standing on ice, not only for days, but their whole lives! And their feet don’t hurt like ours would. It has something to do with blood and an amazing twist that penguins have developed.

Heart attacks are the number 1 cause of death worldwide in the 21st century, but we weren't sure what caused them until 1980.

When Andres Ruzo was a young boy in Peru, his grandfather told him a story with an odd detail: There is a river, deep in the Amazon, which boils as if a fire burns below it. Twelve years later, after training as a geoscientist, he set...

Sharks have been celebrated as powerful gods by some native cultures. And today, sharks are recognized as apex predators of the world's ocean. What is it that makes these fish worthy of our ancient legends and so successful in the seas?...

Dean Ornish shares new research that shows how adopting healthy lifestyle habits can affect a person at a genetic level. For instance, he says, when you live healthier, eat better, exercise, and love more, your brain cells actually...

Join the Amoeba Sisters in their introduction to the circulatory system and follow the pathway of blood as it travels through the heart! This video explains the importance of blood, arteries, and veins, and it also introduces basic heart...

What if traffic flowed through our streets as smoothly and efficiently as blood flows through our veins? Transportation geek Wanis Kabbaj thinks we can find inspiration in the genius of our biology to design the transit systems of the...

That terrible pain the befalls us when enjoying an icy treat! How does that happen? Is there a cure? Let Hank explain.

Now that we've discussed blood, we're beginning our look at how it gets around your body. Today Hank explains your blood vessels and their basic three-layer structure of your blood vessels. We're also going over how those...

Every two seconds, someone in the world has a stroke. One out of every six people will have a stroke at some point in their lives. Strokes deprive brain cells of oxygen and are one of the most common causes of death, and a leading cause...

Your heart gets a lot of attention from poets, songwriters, and storytellers, but today Hank's gonna tell you how it really works. The heart's ventricles, atria, and valves create a pump that maintains both high and low pressure to...

Paul Andersen surveys the circulatory system in humans. He begins with a short discussion of open and closed circulatory systems and 2,3, and 4-chambered hearts. He describes the movement of blood through the human heart and the blood...

If you lined up all the blood vessels in your body, they'd be 60 thousand miles long. And every day, they carry the equivalent of over two thousand gallons of blood to the body's tissues. What effect does this pressure have on the walls...

Howcast - Learn what you need to know about garlic supplements from registered dietician Glen Tobias in this Howcast video.

Howcast - Learn how hardening of the arteries can cause erectile dysfunction in this Howcast video.

Howcast - Learn what causes atherosclerosis, aka hardening of the arteries, from Dr. Dennis Finkielstein in this Howcast video.

Howcast - Learn about the link between diabetes and heart disease from Dr. Dennis Finkielstein in this Howcast video.

Howcast - Learn how high blood pressure, aka hypertension, increases your risk of heart disease from Dr. Dennis Finkielstein in this Howcast video.

Howcast - Learn how smoking increases your risk of heart disease from Dr. Dennis Finkielstein in this Howcast video.

Howcast - Learn how to find out if you have heart disease from Dr. Dennis Finkielstein in this Howcast video.

What is an angiogram and how does it work?