The Heart

Our heart is part of our cardiovascular system, the main responsibility of this system is the transportation of nutrients around the body, the removal of waste products from metabolism and the delivery of oxygen to bodily tissues.  Transportation of these substances occur in our blood, which is predominantly made up of red blood cells (responsible for oxygen delivery), white blood cells (immune response) and platelets (wound repair).  These cells are all transported in our blood plasma, which is mostly water and other components like blood sugar and hormones made by other organs.

The heart is divided into four sections, two upper smaller chambers called atria (atrium when referring to one) and two lower larger chambers called ventricles.  The atria receive blood and the ventricles are responsible for supplying force to discharge blood from out of the heart.  The heart has two pumps, one on the right and the other on the left.  The right side is responsible for our lungs (respiratory system) and the left supplies the rest of the body. 

The heart is the engine of the machine known as the human body.  It beats over 100,000 times per day, pumps over 8000 litres of blood around your body daily and is roughly the size of your fist.  The “beat” of the heart is controlled by a conduction system, which is notably composed of an SA node (sinoatrial) and AV node (atrioventricular).  The nodes work synergistically together to ensure blood flows into sections of the heart at controlled paces to ensure blood doesn’t travel to fast or slow in and out.

Our heart delivers blood to the bodies muscles and organs via our arteries.  These are large carriers of nutrient rich blood that branch off into smaller versions called arterioles that enter even smaller circulatory system vessels called capillaries.  Capillaries deliver the fresh blood from the heart containing nutrients, hormones and other substances to various tissues in our body.  Once this cycle has occurred our veins act as reservoirs, collecting the blood and returning it back to the heart.

Our heart is able to supply nutrient rich blood based on various sources of nourishment such as nutrition from food and hormone production.  However, most notably our heart delivers oxygen to muscles and organs for general function, it generates oxygen via our respiratory system and occurs as follows.  The right side of our heart receives blood that’s de-oxygenated from our veins (as explained above), once it has this used blood it must send it back to the respiratory system (lungs) for re-oxygenation, this transfer of blood to the lungs occurs from the right side of our heart.  After the blood is re-oxygenated, it returns to the left side of the heart for re-circulation back around our body.  This is why the left side of our heart is larger compared to our right, as it has to pump harder to recirculate blood around our entire body compared to the right which pumps a shorter distance, primarily the lungs.  This size variation is due to the heart being a muscular organ and it able to gain size like other muscles, the muscles in our heart are called the myocardium (myo – muscle and cardiac – heart).

As the heart has a continuous flow of blood within it, it is fitted with valves which act like gates as their purpose is to make sure blood travels in one direction within the heart.  The names of these valves are the pulmonary valve, the tricuspid valve, the mitral valve and the aortic valve and they are there to prevent back flow or misdirection of blood.

I hope this brief summary of the heart in this blog gave you another idea of just how amazing our body is.  If we treat it well, it will allow us to experience wonderful things.  Exercise is a large part of keeping this organ healthy, join me in my podcast this week for ideas on how to train efficiently and some food for thought about other areas concerning our heart.

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