“God contracts and expands.” (2:245)

The heart is a fairly small muscle that beats 100,000 times a day and produces roughly 115,000 Joules of energy, enough to boil a cup of water for some tea. Like a flowing river, deoxygenated blood travels from the right side of our body to the right side of our heart via valves and chambers until passing through our lungs, where each breath we take facilitates the oxygenation of every individual blood cell with 4 molecules of oxygen. The now oxygenated blood, continues to progress, never stopping, now through the left side of the heart, again passing through valves and chambers, eventually being pushed out to the rest of our body with the help of the left ventricle. The left ventricle is the thickest, largest, strongest, and most muscular part of the heart because it has the responsibility of pumping oxygenated blood through the aortic valve and aorta to the rest of our body. If this continual circulation is ever interrupted, it can lead to catastrophic outcomes.

There are several ways this flow can be interrupted, many of which happen before birth and require immediate surgery after delivery. Congenital heart defects (CHD) are some of the most common types of birth defects, but as medical care and treatment have advanced many of the babies that suffer from them usually end up living long and healthy lives. Treatment isn’t required while babies are in their mother’s womb, because the circulation of the heart is different before the baby takes its first breaths, and there is normally a mixing of oxygenated and deoxygenated blood. CHD can be mild, like a hole in the heart between two chambers that allows the mixing of oxygenated and deoxygenated blood. Ventricular septal defects and atrial septal defects (holes in the heart) are some of the most common forms of CHD. Sometimes these defects can be resolved on their own or may not be realized until much later in life, or they may require a “patch” repair if they are larger. VSDs and ASDs are associated with Down’s Syndrome, and maternal risk factors including diabetes, obesity, and smoking. Patent foramen ovale (a hole in the heart that fails to close) is found in up to 30% of the general population. It usually requires no treatment and isn’t discovered unless complications like a stroke occur later in life by having a blood clot form, requiring the blood to then travel through the hole, and then be shot up through the aorta into the brain. All babies are born with patent (open) ductus arteriosus – the ductus arteriosus is a fetal blood vessel that allows flow from the right heart to the aorta, necessary when the baby is in their mother’s womb, but incompatible for life after the baby is born. Within the first few days of life, this blood vessel should close and eventually transform into a ligament that helps tether the pulmonary artery and aorta to each other. If closure fails and the ductus arteriosus remains patent, a continuous machine-like murmur can be heard with a stethoscope, and treatment with indomethacin is started. Untreated, a PDA would result in cyanosis (blue/gray skin) and Eisenmenger Syndrome due to decreased oxygen delivery [1].

The heart’s responsibility is not only to provide oxygenated blood to the rest of the body but to also somehow feed itself. The heart’s muscles exhaust 11.6% of the body’s total oxygen consumption in order to maintain its own contractile activity, coming in 3rd after the liver (20.4%) and the brain (18.4%). During contraction or systole, the heart pumps at 120 mm Hg to provide blood through the aorta and arteries. During relaxation, or diastole, the heart expands and allows for blood to fill into its chambers and also flow through the coronary arteries. These coronary arteries are the arteries that will feed the heart itself. Thus, in order to feed itself the heart must relax and therefore allow its coronary arteries to expand and provide blood to itself. When the heart is contracting and providing blood to the rest of the organs it is too constricted to provide blood to itself. Since these branches are located within grooves of the heart, when the heart is systole the arteries are too constricted for blood flow due to increased tension. This is especially true regarding the arteries supplying the left ventricle since it is larger and more muscular – remember this is where the aorta will branch off, providing oxygenated blood to the rest of our body.

This balance between contraction and expansion may remind some readers of the concepts of Qabd (contraction) and Bast (expansion) in Sufism or Tzimtzum in Jewish mysticism, and how one truly feeds the other thus allowing for growth through this cycle of contraction and relaxation. Tzimtzum is used to explain the process of creation, a contraction of infinity happening to give birth to a finite universe [2]. The Sufi tradition is a personal journey described as “contraction and openness are mysterious ‘bargains’ that have been made without the will or intention of the traveler. The first one blocks his or her way; the second one gives him or her wings to fly to new heights [3].” What is perhaps most interesting is that our physical heart performs this contraction and expansion perfectly so long as we take care of it, whereas our spiritual heart can have lapses in this critical exercise. Maybe, if we understand how to take care of our physical heart, we will also find the answer to keeping our spiritual heart healthy. Prophet Muhammad, peace be upon him, emphasizes this connection as follows: “Verily, in the body is a piece of flesh which, if sound, the entire body is sound, and if corrupt, the entire body is corrupt. Truly, it is the heart.”

Some ways to take care of our physical hearts include incorporating more physical activity into our daily lives, eating less and healthy, and controlling our stress. Perhaps our spiritual health would also benefit from these and similar activities, including regular acts of worship, fasting, controlling our temper, and being kind to others. When we don’t take care of our physical heart, it begins to fail since oxygen ceases to be delivered to our heart and the electrical currents can no longer travel effectively, thus resulting in a heart attack.

Coronary artery disease is the leading cause of death worldwide, and especially in developed countries. The deadliest heart attack occurs if there is a blockage of the left anterior descending coronary artery, which is why it is tragically termed the “widow maker.” Beginning from adolescence, arteries begin to accumulate fatty streaks and progress to an atherosclerotic plaque. This plaque can lead to several disastrous complications such as follows:

• a narrowing or complete obstruction of an artery, impairing blood flow and leaving the heart thirsty for oxygen
• a stroke due to a blood clot caused by decreased movement, breaking off and flowing to the brain
• a weakening of the vessel wall leading to an aneurysm, the vessel bursting

For some patients, a heart attack becomes a wakeup call in order to make the many necessary lifestyle changes that are necessary in order to live a long and healthy life. However, 20% of patients will experience a second heart attack. As the heart gets weaker and weaker it can eventually develop cardiorenal syndrome, a complication that results from the heart being unable to pump effectively resulting in it getting backed up in the heart and the right side of the body. This increase in volume in the body is further exacerbated by the kidneys, which continue to retain fluids and thus cause the body to become overloaded. This leads to edema, or swelling, in the legs that can eventually progress to the lungs and cause congestive heart failure. As the kidneys try to ameliorate the fact that the heart is not pumping effectively, they ultimately worsen the situation leading to end-stage renal disease and stage D heart failure.

Of course, as with almost all medical conditions, these fatal results can be prevented much earlier with lifestyle changes, even before introducing medical intervention with prescription drugs or other procedures. These lifestyle modifications include moderate aerobic exercise at least 3 times a week, a diet rich in vegetables and low in fats, sugars, and carbohydrates, smoking and alcohol cessation, and weight reduction (which would come as a result of these modifications). It is also important for patients that are already dealing with hypertension, diabetes, and hyperlipidemia should keep them well-managed and controlled.

Maybe similarly, some simple lifestyle changes, such as putting aside a few minutes every day to reflect, can be the secret to keeping our spiritual heart healthy. Our heart must remain healthy to keep the rest of our body healthy. Considering the close relationship between our physical and spiritual heart, our spiritual heart must be kept healthy to keep the rest of our spiritual body healthy. Spiritually healthy individuals will further reinforce the health of our community, for Prophet Muhammad, peace be upon him, says, “The believers in their mutual kindness, compassion and sympathy are just like one body. When one of the limbs suffers, the whole body responds to it with wakefulness and fever.”

“As the whole of existence is in His grasp and at His free disposal, it is He Who directs and disposes of all things, from the heavens to the human heart… When God wills, He contracts a heart so tightly for what only He can provide that only He can satisfy it. By contrast, He expands and exhilarates it to such an extent that it needs nothing. Contraction is caused by God’s Majesty; openness is caused by His Grace. (Fethullah Gülen, Emerald Hills of the Heart).”

References

• https://www.heart.org/en/health-topics/congenital-heart-defects
• https://www.britannica.com/biography/Isaac-ben-Solomon-Luria#ref163236
• http://fgulen.com/en/fethullah-gulens-works/key-concepts-in-the-practice-of-sufism-1/qabd-and-bast-contraction-and-openness

Arteries and veins differ in many ways, including diameter, strength, durability, and valves. Arteries have thick walls that can withstand high pressure. When the heart pumps blood, there is high pressure in the arteries, which we call blood pressure. High blood pressure is necessary for the heart to pump the blood to parts of the body, especially to the brain. In fact, in order to send enough blood to the brain, the sympathetic nerves press against the muscles around the walls of the arteries, by which the pressure is raised further and blood carried to every part of the body. The walls of arteries are thus created thick and strong so that they can resist such high pressure. When the system breaks down and the pressure is higher than necessary, the arteries may tear, resulting in bleeding in the brain, paralysis, or even death.

The walls of the veins, in contrast, are created thin. The arteries are vessels that feed us, while the veins shuttle used blood back to the heart. The arteries do not expand much, nor do they store much blood. No more than 15% of the blood in the body is found in the arteries.

The veins can expand due to their thin walls and store more blood. A total of 65% of the blood is found in the veins. While the arteries are equipped with features to function with little blood and high pressure, the veins are built to hold more blood, but at a lower pressure. The veins function as a blood tank that is tapped immediately in times of bleeding, especially to delay the death of the brain. In case of bleeding when the brain cannot get oxygen, the body declares a state of emergency. The sympathetic nerves convey messages to the arteries and veins. The muscles in the arteries constrict and stop unnecessary flow into organs and tissues other than the brain and the heart. The aim is to send more blood to the brain. The veins constrict simultaneously, and the blood in their store is pumped first to the heart and then to the brain.

It is dangerous when an artery bleeds. It may lead to excessive bleeding because of the high blood pressure, and death could ensue. Conversely, a person does not lose much blood when a vein bleeds, for blood pressure is virtually non-existent in the veins. Surgeons are especially careful about puncturing an artery during an operation because it is hard to stop the blood that spurts out of the arteries.

The arteries are not found close to the skin; but are located deep under the skin. The arteries, especially those in the arms and legs, pass from among the muscles so that they cannot be easily harmed. The veins are created immediately beneath the skin. Bleeding of a vein does not pose a huge threat as bleeding of arteries.

A question may tug at your mind at this point: why aren’t both vessels created deeper and thus protected?

Nurses cannot use the arteries when they administer medicine, blood, or serum because the arteries refuse blood from outside due to the high pressure. Therefore, only the veins accept serum or blood externally. As the veins are in plain sight right under the skin, the job of nurses is made easier. The jobs of surgeons also becomes easier because the arteries lie deep within and the veins lie along the surface.

The arteries do not have valves to stop the reverse flow of blood because the blood is already pumped with high pressure. There are valves only between the heart and the arteries. If it weren’t for these valves, the blood pumped from the heart would flow back, causing heart failure, and the brain would not receive blood. The veins by contrast are equipped with valves to stop blood from flowing back.

When we move our legs, the blood is jammed in the veins. The closing direction of the valves are placed so as to lead to the upward movement of the blood. When we move, the blood in our legs moves upward and when we stop moving the blood does not flow back down because the valves close with the end of the movement. The valves in our veins are present only in those that are below the heart. There is no valve in the vessels above the heart, as they would be rendered useless due to gravity.

e rarely think about our veins and arteries, but they have been perfectly created to serve our body.

We tend to overlook our skin, but it performs many vital functions for our bodies – including coming to our rescue in emergencies.

Since it is designed to function within very precise limits, our body is very susceptible to small temperature changes. Since abnormalities in these changes occur, the body has various mechanisms to keep its temperature constant. One of these mechanisms works by changing the amount of blood in the veins underneath the skin. When talking about body temperature, it is important to distinguish between the internal and external body temperature. The internal temperature is the temperature of the brain and internal organs, while the external body temperature is the temperature of the skin.

Normally, arteries that transport clean blood, and veins that carry dirty blood, are not connected; therefore clean and dirty blood never mix. However, as a consequence of some illnesses or birth defects, an abnormal bridge between arteries and veins may be present. This kind of condition is usually called arteriovenous shunts, or arteriovenous fistula. In these kinds of situations, blood is pumped directly from arteries to veins. In other words, clean blood flows towards dirty blood. Normally, the clean blood has to travel the body, providing oxygen and other supplements to cells, while collecting carbon dioxide and returning to the heart to be cleaned again.

An incredible network for the transportation of substances from the blood in arteries and veins has been created. If this system, known as the “capillary network,” did not exist, none of our organs could be fed, and the circulatory system would not be able to provide its vital function.

The system is necessary for two reasons. The speed of the blood in the arteries and veins is too fast for anything to be transported to the organs, and their walls are too thick to allow transportation of substances. Therefore, the blood travels from the arteries to the capillaries, and after the trading of oxygen and other substances with carbon dioxide is completed, it flows to the veins. If any kind of abnormalities exist, the blood flows directly from the arteries to the veins, therefore skipping the capillaries. As a consequence, the organs aren’t fed and the blood gathers in the veins without fulfilling its purpose. Naturally, the oxygen and nutrition balance of the organs gets messed up. The blood is pumped out of the heart with no purpose and heart failure becomes inevitable.

The capillary network has been assigned the task of communication between arteries and veins. The skins is our only organ where the blood flows directly from arteries to veins; AV shunts accomplish a very important duty in this function.

There is a network of veins underneath the skin. The number of veins in this network is so many that if they were completely filled up, they could hold up to two liters of blood in the skin. Blood is pumped to the skin for two purposes: to provide oxygen and nutrients to the cells, and to collect carbon dioxide and waste products in the cells, as is done with every organ; and to monitor the internal temperature of the body by sending blood to the skin if the temperature gets too high, similar to what radiators in cars do when the engine gets too hot.

There is also the subcutaneous fat tissue underneath the skin which acts as an insulator. The vein network mentioned above is inside this fat tissue. There is a continuous flow of blood from the capillaries that feed the skin towards this network of veins. Moreover, especially in areas where the skin is exposed – such as the hands, feet, face and ears – there is a blood flow from the small arteries towards this network of veins. Contrary to other organs in the body, blood flows directly from the arteries to the veins. If this direct blood flow did not exist, the amount of blood in the skin’s veins would be close to zero, because the amount of blood necessary for skin nutrition is very little. However when the internal temperature rises too much, the amount of blood, which is normally close to zero, can suddenly increase to as much as 30% of the blood pumped by the heart. In this case, the body’s internal temperature is being transported to the skin. This is an incredibly efficient cooling system. However, if the weather is cold, the AV shunt veins are switched off and the skin’s blood flow is decreased until close to zero, therefore maintaining internal temperature. The fat tissue underneath the skin also has a very important function, as it acts as insulation, helping maintain temperature.

Body temperature and the body’s systems work in perfect coordination with each other. We can observe a very simplified version of this system in computer based air conditioners. However, when we reflect upon the incredibly sophisticated cooling system of the human body, we come to the conclusion that no other system is as perfect as that.

The hypothalamus, which has various vital duties for the brain, was also given the very important mission of controlling the body’s temperature. There are hot and cold heat receptors in various parts of the hypothalamus. When body temperature increases, these receptors are activated. As a consequence of this warning, skin veins all over the body expand. Simultaneous with the expansion of the veins, sweat is excreted.

The hypothalamus also has the duty of suppressing the mechanisms that produce heat throughout the body. For example, trembling is stopped and general metabolism is slowed down to decrease body temperature. As metabolism slows down, the production of heat becomes minimal, and cooling takes place. In conditions where the body temperature is too cold, some hormones secreted in the hypothalamus trigger the pituitary, and then the thyroid, hormones. Since thyroid hormones are responsible for increasing metabolism, body temperature increases. However if body temperature increases above normal, the control of the hypothalamus on the thyroid is reversed, and thyroid hormones are decreased, therefore decreasing body temperature.

There is one more reason for placing so many veins in the perfect and miraculous body’s skin: except for extremely cold weather conditions, quite a large amount of blood exists in these veins that are not used for nutritional purposes. Some of our organs act as storage for blood; two of the most important ones are the spleen and liver. Another one is the skin. In the course of losing blood, or an illness that increases the need for blood, the spleen and liver shrink. As a consequence of this shrinkage, the blood inside them is sent to the heart, through veins, and distributed to the areas in need of blood. This increases the heart rate.

A similar scenario occurs in the skin. The veins responsible for cooling shrink, and the blood they contain is sent to the heart with the help of the main veins, therefore helping the heart pump. During heavy loss of blood, the blood in the skin comes to the rescue. Patients who are losing blood have incredibly cold and pale skin. This is because the blood in the skin has reduced to a minimum.

The obverse of this happens in an illness called erythromelalgia, where more blood than normal flows from the arteries to the veins in the skin. This is mostly seen in the hands, feet, nose, and ears, since AV shunts are more prevalent in these areas of the skin. The symptom of this illness is burning pain, which is triggered by heat and soothed by cool temperatures. The nutrition of the skin decreases and some substances produced because of the absence of oxygen increases redness, heat, and pain, since some of the capillaries feeding the skin shut down and all of the blood flows from arteries to veins with the AV shunts.

Our skin protects our muscles and bones, and contributes to the beautiful aesthetic of our body. It provides our sense of touch, and is therefore a means for us to experience the material world, as well as providing temperature control for our bodies. It can clearly be seen that the relationship between the skin and the veins could not have evolved by the consequence of coincidence.

We vessels can be divided into three main groups in terms of structure and function. The ones with thicker walls, which bring every organ the blood they need from the heart, are the arteries. The pressure inside us is higher and we easily carry blood to the organs. The ones with thinner walls, lower pressure, and larger inner space are called veins. As a matter of fact, both arteries and veins have a three-layered structure that is very suitable for holding a fluid like blood. Since our walls are strengthened with both connective tissue and smooth muscle layers, we bear the pressure coming from the heart and help blood proceed by contracting and relaxing. Since arteries are directly subjected to the strong pressure from the heart, our walls were created in a thicker and stronger form. Since the veins return blood to the heart and thus have lower pressure, we have valves that close after blood passes, so it does not flow backward due to gravity. This is a serious challenge for the blood passing through your legs. Varicose veins might develop due to weight gain from pregnancy or obesity, which increases pressure on the legs, or to hours of standing, walking, or running on hard surfaces.

Capillaries are the most delicate blood vessels, with walls made of a single layer of epithelium, which enables us to exchange substances between blood and tissues. As blood vessels, our total length is about 120,000 kilometers. Try to imagine if a fisherman’s net were made from a rope of this length and how wide it would be! And yet, such a vast network of blood vessels is located in your body, and capillaries take blood to every part, without neglecting an area as tiny as the head of a pin.

The well-being of your organs is directly related to us. If our interiors begin to narrow, because of fatty cholesterol plaque for instance, then we begin to lose our flexibility. This means malnutrition for that organ, since a lesser amount of blood than expected can come. If a blood clot sticks to our wall and blocks the blood flow, the relevant organ may be in terrible trouble. If other arteries supply blood to that organ, then it can handle this, but if a main artery is blocked and if secondary channels do not exist or are insufficient, you experience infarction. Taking this into consideration, you need to be careful what you eat and lead a physically active life. When you get old, if sufficient blood does not pass through us in your brain, failures with brain activities appear and you go senile. As the walls of veins and arteries have a rich network of nerves, we let the suitable amount of blood flow according to the need of the organ we’re serving, under the control of the autonomous nervous system. While blood vessels that are connected to an organ not currently requiring much blood contract to reduce the amount supplied, those that are connected to currently more active organs expand. And dear Peter, the greatest blessing here is that none of these activities require any conscious effort from you; everything works smoothly without your even being aware.

This wonderful network of ours finds its value in the vital fluid we carry. If it weren’t for blood, we would have no value at all, and such a perfect means of distribution would be unnecessary. Even the duty of the heart is to make this fluid circulate throughout the body. Now, let us step aside and allow blood to have the floor.

When we have been sitting or lying for a long time we can suffer from orthostatic hypotension due to an insufficient operation of the sympathetic nerves.

When we are lying down, the blood pressure in our arteries is pretty much equal throughout the body. When we stand up, the blood pressure is affected by the gravity and increases in the vessels under the heart, while decreasing in the brain. If we lie down again, the blood pressure in the arteries balances once again. If these changes cannot be naturally controlled, then we may suffer an increase or decrease in blood pressure, which could result in a fatal injury.

There are baroreceptors in the walls of main arteries whose tasks are to measure constantly the blood pressure and to send data (electrical signals) to the brain, informing it about the blood pressure in the body. These baroreceptors are located in the aorta as it leaves the heart and in the carotid artery as it enters the brain. With the onset of hypertension, the frequency of the signals that are sent to the brain increases and this drops in case of hypotension. The center of vessel movement in the brain, with regard to the frequency of electrical signals it receives, perceives a low or high blood pressure.

In the brain is a vasomotor center; this continuously controls the blood pressure and regulates it. This center constantly receives data about blood pressure. If the pressure decreases, the signals of the sympathetic nerve increase. If the pressure increases, the signals to the parasympathetic nerves are suppressed. As a result of sympathetic irritability, the heart begins to beat faster and stronger. It pumps much more blood in a unit of time, and thus the blood pressure increases. The arteries and veins also constrict and owing to this constriction in the arteries, the blood pressure increases further. As a consequence of constriction in the veins, the extra blood that is stored inside the veins is pumped into the heart. Now, as the heart is receiving greater volumes of blood, it works faster and contributes to the increase in the pressure. In the meantime, as a result of the suppression of parasympathetic nerve signals, the heart contracts faster and stronger, thus pumping much more blood.

As the blood pressure rises, the mechanism which is in charge of reducing the pressure via vasomotor center is triggered. While pressure is applied to the sympathetic nerves, the signals that are being sent to the heart and vessels decrease. Thus, the rate of systole and the amount of blood which is being pumped decreases. As the arteries receive less blood the volume of blood in the system falls off and as the arteries and veins expand, the blood pressure falls. Due to the dilatation in the veins, the volume of blood which is sent to the heart also decreases and as a result the heart pumps less blood and the blood pressure drops.

However, by triggering the parasympathetic nerves, the signals that are sent to the heart increase. This helps to slow the heart down and ensures that there is less blood pumping through the system. As a result, the blood pressure which has been reduced via the sympathetic system is reduced even further with the parasympathetic system. At this point, it is necessary for there to be a rapid drop in blood pressure, which is provided by the simultaneous functioning of different mechanisms.

We cannot control this system and it acts extremely rapidly and with great elegance. Even in the systole period, when the heart is pumping the blood and there is a short and sudden increase in pressure and in the diastole period, when the heart relaxes and there is a short and sudden decrease in pressure, the system is in charge and functioning at every second, operating to increase the hypotension and to decrease the hypertension. The average healthy human heart beats 70 times per minute. Consequently, there are 70 systole and 70 diastole stages every minute; thus a normal balance can be maintained by decreasing the pressure, which increases 70 times every minute, and by increasing the pressure, which decreases 70 times every minute; this is how the body maintains a normal balance. In other words, this system functions 140 times every minute. Is it possible that this system, which operates throughout our life, a system that we are not aware of, a system that is so sensitive and vital to our lives, a system the details of which have only recently been understood after centuries of observation could be nothing more than a coincidence?

The pressure regulating system mentioned above carries out other important tasks while we are sitting and standing as well. The amount of blood going to the brain is related to the maintenance of a difference in blood pressure between the arteries and veins and to the recirculation of blood. In connection with hypotension, the pressure in the veins to the brain decreases, in order to partially compensate for the decrease in the arteries. By preventing a decrease in the difference of pressure (perfusion pressure) between the two systems, the continuity of blood going to the brain can be maintained.

In addition, a small decrease in the blood going to the brain can lead to an increase in acidity and carbondioxide in the brain tissues and to a decrease in oxygen; this results in the dilatation of the blood vessels in the brain. When these systems go into action anyone who is not suffering from orthostatic hypotension will have a stable amount of oxygen consumption in the brain when they stand up, and thus not experience dizziness.

In fact, scenes from karate movies are wonderful displays of the perfect functioning of this system. In such scenes, the fighter will jump up, and then suddenly fall to the ground; he will then suddenly spring up and performs different moves. Certainly with every movement, the blood pressure changes suddenly, but as a sign of the Creator’s mercy and grace, the body is able to maintain a balance. Should not the person watching these scenes stand in amazement, thinking: “Oh my God, what an incredible order! How great is Your knowledge, power, wisdom and art!”

As mentioned at the beginning of the article with reference to an actual sad incident, when a person whose sympathetic system is not functioning normally suddenly stands up, they can suffer from dizziness and perhaps even faint due to irregular blood pressure.

For patients suffering from orthostatic hypotension patients, it is important that they do not stand up rapidly. In addition, exercises that encourage the use of leg muscles before standing up will help pump blood towards the brain.

Pause for a minute… What would happen if this miraculous system did not exist? Consider how much time it would take you to merely get out of bed every day!