Circulatory System

Overview of the Circulatory System

Here are some of the cool things that our class has learned about the heart, how it works and what it does:

The size of an animal’s heart depends on the size of their body. For example, a brontosaurus’ heart is as big as a dump truck. By contrast, a human heart is only the size of your fist.

The heart is specially designed to run off of electricity. Our heart needs electricity. Cells located in the right atrium set the rhythm for the heart. Your heart beats 60 times per minute, 60 minutes per hour, 365 days per year. That’s 31,536 beats per year!

The heart is divided up into internal parts. The heart has four chambers. Your heart has four valves.

Your heart’s job is to circulate blood throughout the body. Your heart pumps blood that goes to your brain and then it goes to the rest of the body. When you have a heart attack, your heart stops circulating blood. The blood travels 16 inches per second out of the left ventricle and into the artery.

Does your heart control your emotions -- or the other way around?

Sometimes when we have a strong emotion, we feel it in our body. Some of the body responses that our class members have had in the past when they experienced failures have been:

cheeks getting red
a heavy feeling going down the chest and into the stomach
tightness and feeling scrunched up
heart beats faster
heart seems to stop

So how does it work??

How Your Heart Actually Controls Your Brain

Curious Kids: how does our heart beat?

Read Along

Visual Encyclopedia pages 190-191

This site provides a more accessible description of recent research into the connection between emotional experiences and heart rate variability: The Science of HeartMath

Want to go deeper and understand how this works?

So, how do the heart and sympathetic nervous system actually interact to cause these changes and experiences? Watch this video to go deeper into how this works!

Want to learn more about the heart's autonomic responses? Read pages 78-79 in the Visual Encyclopedia.

How does the heart actually work?

Let's meet your heart! You don't need to worry about picking up all the terms, but check out what it really looks like, and how all the parts work together to keep you going!