Human Body

Self Reflected


Video credit: Will Drinker

 

Follow the light as it moves across the golden surface. What you see is a portrait of your brain—the communication happening in your own head at this very instant. Self Reflected is your brain perceiving itself.

Heart: The Engine of Life Educational Resources—The Franklin Institute

How Your Body is Like a Factory

If you go inside the walls of a car factory, you’re likely to encounter many different teams doing many different things. One team might make steering wheels. Another team might make seats. Other teams may assemble different parts of the engine. 

But even though each team is doing its own thing, they all share a common goal: to make cars.

Your body operates in much the same way. Different systems within your body are responsible for different jobs, yet they all share the common goal of keeping you alive.

Heart: The Engine of Life Educational Resources—The Franklin Institute

Blood Types: What’s the Difference?

To the naked eye, everyone’s blood looks the same. But if you look at blood samples under a microscope, it’s obvious that there are some big differences.

Heart: The Engine of Life Educational Resources—The Franklin Institute

All About Scabs

The human body has a pretty ingenious way of protecting itself from excessive blood loss. Yes, you guessed it: Scabs.

But don’t be fooled: Scabs are a whole lot more than dried blood. In fact, there’s a whole fascinating structure to how scabs form.

It all starts with platelets, which are irregularly-shaped, colorless bodies in the blood. When bleeding from a wound suddenly occurs, the platelets gather at the wound and attempt to block the blood flow. Calcium, vitamin K, and a protein called fibrinogen help the platelets form a clot.

Heart: The Engine of Life Educational Resources—The Franklin Institute

Blood Vessels

Blood vessels may be tiny but they cover a lot of ground.

The smallest blood vessels measure only five micrometers. To give you some perspective, a strand of human hair measures about 17 micrometers.

But if you took all the blood vessels out of an average child and laid them out in one line, the line would stretch over 60,000 miles. An adult’s would be closer to 100,000 miles long.

There are three kinds of blood vessels: arteries, veins, and capillaries. Each of these plays a very specific role in the circulation process.

Heart: The Engine of Life Educational Resources—The Franklin Institute

White Blood Cells

Think of white blood cells as your germ-fighting army. These cells are continually on the lookout for signs of disease.

When germs appear, white blood cells have a variety of special tactics they can deploy to knock out the invaders. In some cases, they produce protective antibodies to overpower the germs. Other times, white blood cells surround and devour the bacteria.

You might say that white blood cells live fast and die young. They have a rather short life cycle, surviving only a few days to a few weeks.

Heart: The Engine of Life Educational Resources—The Franklin Institute

Red Blood Cells

Red blood cells are the key to life. They are constantly traveling through your body, delivering oxygen and removing waste. If they didn’t do their job, you would slowly die.

Red blood cells contain a protein called hemoglobin that gives blood its red hue. Hemoglobin contains iron, which makes it an excellent vehicle for transporting oxygen and carbon dioxide.

Heart: The Engine of Life Educational Resources—The Franklin Institute

It’s Alive!

Did you know that your blood is alive?

It’s true. Each drop of blood is full of living red and white blood cells that deliver essential elements and remove harmful waste.

Without blood, your body would stop working. And without the heart, your blood would stop flowing.

Heart: The Engine of Life Educational Resources—The Franklin Institute

Structure of the Heart

Although most people know that the human heart doesn’t bear much resemblance to a heart drawn on a Valentine’s Day card, the image can still be a useful way to learn and remember the parts of the heart.

The heart consists of four chambers: two atria on the top and two ventricles on the bottom. Looking at the Valentine’s Day heart, the two rounded humps at the top are rounded like the top of a lower-case “a.” The bottom is shaped like a “v.”

Heart: The Engine of Life Educational Resources—The Franklin Institute

How Your Heart is Formed

 A human fetus forms in a very precise order.

While the heart is one of the first organs to begin development, it takes several weeks before it resembles the four-chambered structure that we all know.

During the fetal heart's developmental stages, the heart actually takes on several distinct appearances. These heart structures resemble other animal hearts.

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