How the heart actually pumps blood
Adults BiologyFor most of history, scientists weren't quite sure why our hearts were beating or even what purpose they served. Eventually, we realized that these thumping organs serve the vital task of pumping clean blood throughout the body. But how? Edmond Hui investigates how it all works by taking a closer look at the heart's highly efficient ventricle system.
How Many Heartbeats Do We Get?
Adults BiologyEver wonder how the heart symbol came to stand for the actual heart? And why do we speak of the heart as the seat of love, when love really happens in our brains? Is it true that animals only get a billion heartbeats? This week, we give you enough cool cardiac science to make your heart skip a beat.
The science of stage fright (and how to overcome it)
Adults BiologyHeart racing, palms sweating, labored breathing? No, you're not having a heart attack -- it's stage fright! If speaking in public makes you feel like you're fighting for your life, you're not alone. But the better you understand your body's reaction, the more likely you are to overcome it. Mikael Cho advises how to trick your brain and steal the show.
How do pain relievers work?
Adults BiologySome people take aspirin or ibuprofen to treat everyday aches and pains, but how exactly do the different classes of pain relievers work? Learn about the basic physiology of how humans experience pain, and the mechanics of the medicines we've invented to block or circumvent that discomfort.
What are those floaty things in your eye?
Adults BiologySometimes, against a uniform, bright background such as a clear sky or a blank computer screen, you might see things floating across your field of vision. What are these moving objects, and how are you seeing them? Michael Mauser explains the visual phenomenon that is floaters.
Life by the Numbers
Adults BiologyThere are now more than 7 billion human beings on Earth, and that got me wondering: How successful are we compared to other species? I take a look at out how our numbers stack up to some other domains of life. It turns out that biomass, or what things weigh, can be more important than how many of something there are. Find out how our numbers stack up against everything from bugs to bacteria, and get ready for some mind-blowing numbers!
Why do we cry? The three types of tears
Adults BiologyWhether we cry during a sad movie, while chopping onions, or completely involuntarily, our eyes are constantly producing tears. Alex Gendler tracks a particularly watery day in the life of Iris (the iris) as she cycles through basal, reflex and emotional tears.
How sugar affects the brain
Adults BiologyWhen you eat something loaded with sugar, your taste buds, your gut and your brain all take notice. This activation of your reward system is not unlike how bodies process addictive substances such as alcohol or nicotine -- an overload of sugar spikes dopamine levels and leaves you craving more. Nicole Avena explains why sweets and treats should be enjoyed in moderation.
The Invisible Universe Of The Human Microbiome
Adults BiologyThe next time you look in a mirror, think about this: In many ways you're more microbe than human. There are 10 times more cells from microorganisms like bacteria and fungi in and on our bodies than there are human cells. But these tiny compatriots are invisible to the naked eye. So we asked artist Ben Arthur to give us a guided tour of the rich universe of the human microbiome.