The heart’s basic function is to pump cells carrying oxygen and nutrients to all the cells of the body by means of blood inside arteries; and carry the waste products—mostly carbon dioxide—of all the living cells of the body away from them by means blood inside the venous system. If there was no blood flow, the cells of the body would become extremely unhealthy and start dying off, some within minutes, like our brain cells, others within a few hours. The heart provides the pumping action to keep the blood flowing strong and smooth enough to reach the approximately 37.2 trillion cells in the average human body. Blood flow through the body is classified as systemic flow (from the heart to all of the body and back, except the lungs) and pulmonary flow (from the heart to the lungs and back). This differentiation is because it is at the lungs where the blood gets rid of the carbon dioxide waste and where the body acquires the oxygen that all of its cells need. The heart is able to keep the deoxygenated waste filled blood coming in from the body separate from the freshly re-oxygenated blood coming from the lungs by means of four heart chambers, called atria and ventricles. The heart itself gets it own oxygen blood supply and dumps its own carbon dioxide through a system of veins and arteries called the coronary blood vessels.
The heart, though “just” a pump, is one of the most amazing pieces of engineering around. In the average human being’s life, it pumps (or beats) about three billion times. If we look at a single red blood cell that starts it journey in one of the heart’s chambers, it takes about 20 seconds for that red blood cell to circle the whole body and get back to where it started.
Our circulatory system—the elastic tubes connected to the heart through which blood is pumped to the cells (arteries), brought back to the heart (veins), or in the very small spaces around cells in between the artery and the vein (capillaries)—is just as amazing a system. If all of our arteries, veins and capillaries could be laid out in a single line, the line would span Earth at its equator more than twice. Our circulatory system plays a cardinal role in our ability to control our body temperature. Our blood vessels act as a barrier between the body and the brain. It is called the blood-brain barrier. Without it, bacteria would be able to get right into the brain, as well as other harmful substances as well. (Unfortunately, some life saving medications also cannot, posing a big problem).
Let’s not forget our amazing red blood cells that are an integral part of the cardiovascular system. These tiny cells that carry oxygen to all the body’s cells and carry off carbon dioxide to the lungs make approximately 250,000 trips of the body before they go back to the bone marrow, where they were formed to die. About 8 million of them die at any given second, and they are replaced by the same number. (If they do not get replaced at the same rate, we develop anemia). Each cell survives for about four months before it dies off.
Because life is hard and we live in an entropic universe, the heart, blood vessels and red blood cells can become damaged and unhealthy. Heart disease is the top killer of men and women. The heart can suffer from relative blood supply impairment, called angina, to an outright blockage of blood supply, called a myocardial infarction (heart attack). Its muscle can get overworked and start enlarging, and this illness is called cardiac failure. The circulatory system can get plugged up, in a process called atherosclerosis, can get hardened, called hypertension, or can get weakened in its valves and veins, and varicose veins happen. As mentioned before, most illnesses of the red blood cells involve various forms of anemia, but it can rarely also happen that the shape or size of the red blood cell can change, in cases of illness such as spherocytosis or macrocytosis.
What can we do to manage our cardiovascular health best?
Here are a few easy-to-remember ways to combat heart disease:
- Work as hard as we can to avoid being overweight. Every kilogram of fat requires about an extra 3,200 metres of blood vessels.
- Exercise is a great way to achieve this. Too little activity is the biggest risk factor for heart disease. If we exercise at moderate intensity for twenty five minutes a day; or just over ten minutes of vigorous intensity a day; or a combination of the two; we halve our risk in comparison to our other self who does not do this.
- Being depressed is a great heart risk to especially women younger than 55. If you believe yourself to be depressed, please get treated. (Yoga is a great way to combat this, but psychotherapy and medications are just as effective).
- Sitting is the new smoking. If you can sit instead of lying down; do so. If you can stand instead of sitting, please go ahead. If you can walk, instead of standing, walk away. You get the drift.
- If you also smoke, stop.
- Eat dark chocolate (in moderation, as too much may lead to being overweight!) as these contain micronutrients called flavonoids, a specific type of antioxidant that keeps our hearts and vessels healthy.
- Control your carbohydrate intake to ensure that you do not develop insulin resistance and eventual diabetes.