the cardiovascular system highlighted within a drawn man

Your Lungs and the Cardiovascular System

Last updated: October 2020

COPD affects your lungs, and it may also affect your heart. This is because your heart and lungs work together to send oxygen to the various cells of your body to keep you healthy. Today, we're going to take you on a fun and educational ride through the cardiovascular system, which includes your blood vessels and heart. We promise to keep this an easy read for your educational enjoyment.

The heart can be affected by COPD

Your heart is a fist-sized organ that sits on the left side of your chest and is somewhat slanted to the left. It is a muscle that is responsible for pumping blood through your lungs and entire body. Your heart can be affected when you have a disease like COPD.

The air around us contains about 21% oxygen. Let's take some fake eyes and place them on one oxygen molecule. We will now follow it as it travels through your body. It is inhaled, travels through your respiratory tract, to an air exchange unit called an alveoli.

Pulmonary capillaries

Once oxygen exits the alveoli and enters the bloodstream, it begins its journey in the pulmonary capillary system. As soon our oxygen molecule enters this stream it binds with a hemoglobin molecule. When this happens the blood turns bright red.

Pulmonary vein

Freshly oxygenated blood travels from the capillaries to the right or left pulmonary vein, and these deliver oxygen to the left atria of the heart.

Left atria

Blood collects in this chamber momentarily until it is pumped through a valve called the bicuspid valve to the left ventricle. This and other valves of the heart are essential because they prevent blood from backing up. Our oxygen molecule travels smoothly from the lungs to left atria, and then to the...

Left ventricle

This is the largest chamber of the heart. It is also the strongest. This is necessary because it is responsible for creating a large enough pressure for pumping blood through your entire body.  A doctor can measure how hard it is working by taking a blood pressure. A high blood pressure means it is working too hard. Right now our person's blood pressure is normal (120/80), and we follow our carbon dioxide molecule as it leaves the left ventricle through the Aortic Valve to the aorta.


The aorta is the largest artery. The arterial system contains freshly oxygenated blood from the lungs, and is therefore bright red. They carry oxygen molecules to all the cells of your body. By peering through our fake eyes, we go on a rollercoaster-like ride through a series of twists and turns to a...


Here, cellular metabolism takes place, and our oxygen molecule is used up to make energy so the cell can do its job. Our fake eyes pop off our oxygen molecule. A waste product of cellular metabolism is carbon dioxide. We will now place our fake eyes on a carbon dioxide molecule and continue with our journey.  We watch as it travels through...


After oxygen leaves the bloodstream the blood turns a darker color, or a purplish-blue color. As soon as oxygen leaves a hemoglobin molecule, a carbon dioxide molecule attaches to it.  We follow -- by looking through our fake eyes -- our molecule as it takes various twists and turns through veins to the right atria. If you look at your hands and arms, you can probably see some bluish veins. The best place to see them is the back of your wrist.

Right atria

This is the smallest chamber of the heart. In the upper portion is a sinoatrial (SA) node, and this creates an electric charge responsible for the beating of your heart. Un-oxygenated blood travels from the right atria through the Tricuspid valve to the right ventricle.

Right ventricle

This is smaller than the left ventricle. This is because only a light pressure is needed to push blood through the pulmonary valve to the pulmonary artery and to the lungs. Here, veins get smaller and smaller until we find ourselves in the...

Pulmonary capillaries

Now we are back where we started, only in the unoxygenated side. As our carbon dioxide molecule approaches an alveoli, it crosses the alveolar-capillary membrane and into the alveoli.

Finishing the journey

Our carbon dioxide molecule is exhaled from the lungs into the atmosphere. Our ride is now complete. Please take your fake eyes off the molecule and return them to the receptacle to your right. You are free to keep any wisdom learned.

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This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

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