How does your Cardiovascular System Work?

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Place two fingers on your throat, just below your jaw. What do you feel?

Your heartbeat, of course.

This beat is essential to life, it’s an indicator of our health and emotional state, it can change on an instant and it happens everywhere in the body.

It’s easy to think of the cardiovascular system as “the heart,” but your heart is just one part of a whole system. It’s a pump that keeps things running and it has a whole slew of bells and whistles to do it.

The Importance of Blood

It’s not the prettiest topic but in an article about the cardiovascular system we have to talk about the importance of blood—that’s what the whole system centers around.

Our blood is how our body systems are physically connected and work together. Nutrients delivered by the digestive system, the hormones you produce in your adrenals, inflammation reactions from a bug bite, even blushing when you see your fling—if it’s physically happening inside your body, your blood is involved.

For me, it’s easier to think of it as the package delivery system. The body uses the nervous system to deliver messages, like emails or online shopping order, and then the blood is the carrier for all of the packages that your order.

The blood’s highway is our veins and arteries, and it’s engine is the heart.

How your Heart Pumps

The heart has four chambers. The two on top are called the atria and the two on the bottom are the ventricles.

Unoxygenated blood flows from two veins (up and lower vena cava) into the right atrium. When it’s filled, the it drains through a valve into the right ventricle. The blood is pushes through a second valve (pulmonary valve) and through the pulmonary artery into the lungs.

The lungs oxygenate the blood and then send it back into the heart, via the pulmonary vein. The pulmonary vein flows into the left atrium, which drains through a third (mitral) valve and into the left ventricle. It is then pumped out through a forth (aortic) valve and the aorta and on into the body.

The Heartbeat

So what about our heartbeats—what makes that sound? It’s actually those four valves slamming shut. The two inner valves between the atria and the ventricles close simultaneously and the outer valves between the ventricles and the outgoing arteries close just milliseconds later. The quiet between heartbeats is a resting period where the chambers are filling with blood. This happens between 60 and 80 times per minute in adults on average – and those beats make up our heart rate.

Our heart beat is an indication of how quickly our blood is moving through the entire cardiovascular system.

The Whole Cardiovascular System

If the heart’s function is to pump unoxygenated blood to the lungs and oxygenated blood to the body, cardiovascular system’s function as a whole is to move the blood throughout the body.

When the blood leaves the heart and goes into the body, it moves through the aorta, the largest artery. It goes to smaller arteries, then into arterioles, then into the capillaries.

The blood moves through the capillaries, offering the oxygenated and nutrient rich blood to the organs. (Refresher: in the lungs capillaries are also where gas exchange happens to oxygenate the blood, the process is similar through the body with blood).

By the time the blood makes it through the capillaries in the organs throughout the body, it is largely void of nutrition and carrying toxic agents and waste.  The body needs to be able to get rid of waste so that we don’t end up toxic. Blood is pumped through the liver and the kidneys to remove waste before it returns to the heart to be re-oxygenated.

Blood returns to the heart through venules, into veins, then into the vena cava and the whole process starts over again.

Only takes about one minute for oxygenated blood to leave the heart and return unoxygenated and ready to be replenished. That means every minute is an opportunity for a fresh outlook to pump through your body.

Get to Know Your Heart

The exercise for this system is simple.

For the next week, spend one minute three times a day counting your heart beats.

You can do this by placing your pointer and middle fingers on your throat just under your jaw line. Alternatively (and this is a bit more discreet), you can place the back of one wrist in the palm of your opposite hand and wrap your pointer and middle fingers around so they fall inside your wrist just to the outside of the center, like this:

how to check your pulse

This is my left hand checking the pulse on my right wrist. (It’s surprisingly difficult to take a photo like this, by the way.)

Try it when you wake up in the morning, after lunch, and before bed.

Do you notice a difference between the counts throughout your day?

Maybe try before and after a meal, or before and after a nice date.

You might learn a thing or two about what makes your heart beat a little harder or softer.

When does your heart beat the slowest? Fastest? Tell us in the comments!

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