The heart is an incredible organ. This is because it’s responsible for pumping oxygen as well as nutrient-rich blood throughout your body in order to sustain life. This powerhouse, which you can easily wrap your hand around, beats 100 000 times every single day. It pumps between five and six quarts of blood each minute or, put another way, about 2 000 gallons on a daily basis.
The components of the cardiovascular system
Your heart is an essential part of your cardiovascular system. This system in your body also includes all your blood vessels which transport blood from your heart to your body and then back to your heart. You need a healthy heart to be able to perform at your maximum in your fitness routine.
The primary functions of the heart are to:
- Regulate blood supply
- Generate blood pressure
- Route the blood
- Ensure one-way blood flow
How is the heart made up?
The heart is a muscular organ which is located in the thoracic cavity. It lies anterior to the spine and posterior to the sternum. It:
- Weighs approximately between 250 and 350g, and
- Is 12 – 14cm long.
It is termed a cardiac muscle and has a similar characteristic to skeletal muscle in that it is made up of myofibrils containing actin and myosin that cross-bridges to form contractions. The heart (cardiac muscle) is considered an involuntary muscle, meaning that it cannot be controlled.
It is possible to distinguish three distinct layers in the wall of the heart:
- Inner endocardium,
- Middle myocardium, and
- Outer epicardium.
The heart consists of four chambers which are hollow. These chambers are delineated into two interdependent (but separate) pumps on either side. These two pumps are separated by the interatrial septum and interventricular septum.
Each side of the heart has two chambers:
- An atrium, and
- A ventricle.
The atria are smaller chambers that are superiorly located on either sides of the heart. The right atrium gathers deoxygenated blood returning from the lungs to the heart and the left atrium gathers reoxygenated blood that comes from the heart from the lungs.
The ventricles are the inferior chamber of the heart which receives blood from its corresponding atrium and in turn forces the blood into the arteries. The right ventricle receives deoxygenated blood from the right atrium and pumps into the lungs to be saturated with incoming oxygen. The left ventricle receives reoxygenated blood from the left atrium and pumps it into the entire body.
The chambers of the heart are all separate from each other. Major veins and arteries, with the use of valves, prevent a backflow or spillage of blood back into the chambers. These valves include the atrioventricular valves and semilunar valves. The tricuspid valve separates the atrium and ventricle on the right side and the bicuspid on the left side.
Between the right side as well as the left side of the heart are septa dividing the heart into two functional pumps (interventricular septum).
What is the function of the heart
Ventricle contraction pushes the blood from the heart to the body. The amount of blood that is pumped out with each contraction is called the stroke volume (SV). The average adult SV is 75-80ml per beat.
The heart rate (HR) refers to the rate the heart pumps blood into the body. The average person’s heart rate is 70 – 80 beats per minute (bpm). The stroke volume and heart rate combined (SV & bpm) is collectively termed as cardio output. It is almost impossible to gauge a client’s SV but it is possible to gauge bpm. In cardio activity, it is recommended to monitor the client’s heart rate.
There are some conditions which can damage your heart muscle. This makes it weak as well as unable to pump as efficiently as before. These conditions are, among others:
- Heart attack,
- High blood pressure (hypertension), and
- Heart valve problems.
The term ‘cardiomyopathy’ is a general term that encompasses diseases of the heart muscle. Sometimes these diseases are inherited from your family while, at other times, they are caused by other things such as viral infections.
When your heart muscle can’t meet your body’s demands for blood as well as oxygen, it is possible that you could develop various symptoms, such as breathlessness, extreme tiredness as well as ankle swelling. This is called heart failure because of the failure of your heart to pump blood around the body and work efficiently.
A qualified personal trainer will be able to understand the anatomy of the heart and guide you when performing exercise routines so you do not compromise your heart during exercise and sports.