Harming our bodies or health is a betrayal against this incredible gift. One of the major ways people harm the body is through smoking cigarettes.

Smoking harms human health in countless ways. It is one of the main causes of many diseases, such as lung and throat cancer, along with cardiovascular and respiratory track diseases, such as chronic bronchitis. According to the latest report from the World Health Organization, smoking remains the fourth of the top ten risks that threaten human health. Approximately 20-30% of adult fatalities are caused by ailments contributed to by smoking. Recent studies have shown the negative effects smoking has on human reproductive functions.

Effects on fallopian tubes

Smoking has a negative impact on female reproductive organs; this impact is determined by how long, and how much, a woman smokes. It may cause infertility by damaging the fallopian tubes that serve as a ground for the egg to be fertilized by sperm. In many studies, the risk of damage to the fallopian tubes was very high – this danger increases if a woman starts smoking a pack a day before the age of 18.

Effects on female hormones

Many toxic substances in cigarette smoke, including nicotine, directly inhibits the activity of the enzyme called aromatase, which plays a major role in the synthesis of the female hormone (estrogen) in the ovaries. Depending on the biological function, estrogen can be found in three different forms: as estrone, estriol and estradiol. Polyaromatic hydrocarbons found in cigarette smoke stimulate the microsomal cytochrome P-450 enzyme system that degrades hormones in the liver and, consequentially, increases conversion of estradiol with high biologic activity into estriol with the lowest activity. Alkaloids, one of the harmful substances found in cigarette smoke, were discovered to prevent production of progesterone in the ovaries. This plays a role in preparing the womb and in continuation of the pregnancy during the first three months. Therefore, smoking leads to progesterone deficiency during the early stages of pregnancy, causing miscarriages.

Effects on the maturation of the egg

The concentrations of the FSH hormone that is involved in the maturation of reproductive cells in the ovaries are especially high in young female smokers. In other words, a resistance develops against the FSH hormone in the ovaries and higher FSH hormone levels are required for the maturation of the egg. Thus, fertilization problems and missed periods can occur because of an absent reproductive cell. During the treatment of such patients with insufficient egg cell maturation, there is a 50% decrease in the success of the implantation (placement of the fertilized egg into the womb) and the continuation of the pregnancy in smokers when compared to nonsmokers. This means smoking significantly reduces ovarian functions, and ovarian stimulation becomes inadequate at earlier ages in women.

The negative effects of smoking on the reproductive system are also observed during the implementation of reproduction methods such as in vitro fertilization and assisted fertility technologies. The presence of high androgenic hormone levels (pre-metabolites of gender related hormones: androstenedione, DHEAS and testosterone/SHBG) in female smokers has been found to decrease the possibility of pregnancy during in vitro fertilization efforts.

Effects during pregnancy

There are many harmful consequences of smoking during pregnancy, especially for older women who are pregnant. Some of these consequences are premature birth, miscarriage, retardation of development, inadequate baby weight, perinatal mortality, ectopic pregnancy, placental praevia, and placental abruption. Placental praevia is the abnormal placement of placenta in the womb. In this case, depending on the excessive bleeding that occurs after the eighth month of gestation, the lives of the mother and fetus become imperiled, and fetal development is hindered. Placental abruption occurs depending on the premature separation of placenta from the womb, causing excessive bleeding that can also endanger the lives of the mother and baby.

In pregnant smokers, the postnatal ratio of infant mortality and disability increases as a consequence of deficiencies involving lung function and nerve development. These effects are directly proportional to how much a woman smokes. There are also negative impacts when a pregnant woman is exposed to second hand smoke by a spouse or close friend. Harmful metabolites of nicotine reach the baby via the placenta. Furthermore, nicotine is degraded slowly in the liver of a pregnant woman. Inadequate baby weight is related to smoking dosage and time.

Due to smoking in the early stages of pregnancy, the hormone levels of estriol, estradiol, progesterone and hCG, hPL which is secreted from the placenta, have been found to decrease. This reduction, which is observed in parallel with the amount of smoking, can result in miscarriages.

Toxic polyaromatic hydrocarbons have been found to accumulate at elevated ratios in the wombs of women who were exposed to cigarette smoke for a long time. During pregnancy, this situation leads to the deterioration of sertoli cells located in the reproductive glands of male fetuses. These glands assist in sperm production during adulthood, and damage to them can therefore cause a reduction in sperm generation.

An insufficient placental development occurs because of the negative effects of nicotine, cadmiums, and polyaromatic hydrocarbons damage the reproduction of trophoblast cells that make up the placenta. This situation explains the increasing miscarriage ratios among female smokers.

The free T4/TSH ratio in the serum of the umbilical cord, which connects the fetus to the placenta, increases in the babies of smokers compared to those of nonsmokers. This means that in babies of smokers, the thyroid glands may become overactive during birth. Depending on a mother’s smoking habits, this hyperactivity of the fetal thyroid increases the metabolic speed and the amount of consumed oxygen in the body, thus leading to the inadequate development of fetus.

Menopause occurs two-to-four years earlier due in women who smoke, as compared to non-smokers. This is due to the aging of the eggs. The risk of entering menopause before the age of 45 in women who quit smoking at least ten years prior is 87% less than smokers who don’t quit. Therefore, the earlier a woman stops smoking, the lower the risk of early menopause.

Effects of smoking on men

In research studies, it has been discovered that smoking has many harmful effects on testicular development and functions. These effects can be summarized as follows:

• Reduction of semen volume and quality, increase in its adhesiveness, delay in its becoming liquid, and resulting deformation of the sperm.

• Reduction in the number and mobility of sperm cells.

• Delayed sperm nucleus maturation, deteriorated DNA integrity.

• Decrease in the production of testosterone from Leyding cells.

• Decrease in the egg fertilization capacity of the sperm.

As a consequence of these negative effects, male infertility can occur. As the amount of daily cigarette consumption increases, the number, strength, and types of anomalies also increase. In a study conducted in 2010, smoking has been showed to decrease zinc levels in the seminal plasma. As a result of this decrease, oxidative agents populate and DNA breaks take place, thus causing a disruption of sperm functions and infertility. Zinc deficiency at the same time leads to the destruction of seminiferous tubule cells where sperm cells are produced. Paternal smoking generates negative results during the application of assisted fertility methods (such as in vitro fertilization). The damage in the sperm DNA of the father can disrupt the embryo development. The risk of anomalies, cancer, and genetic diseases increases for the fetus.

Cigarette smoking clearly occupies a position as one of the worst enemies of mankind because of its destructive effects on the body. In this case, it does not make any sense to try finding excuses for smoking, for it is harmful to the body that has been loaned to us as a gift and a temporary property.

Cihanoglu is a professor of medicine in KATU, Trabzon, Turkey.

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!

The Earth’s shape is becoming rounder as a result of the construction of projects like the Three Gorges reservoir. The weight decrease due to the melting icecaps has played a major role in these changes.

From time immemorial, humanity has wondered about the shape of the Earth. Over the centuries countless studies exploring the Earth and its shape have been conducted, and they still continue today. With advancements in technology, the methods and measuring devices have constantly changed. In earlier periods the Earth was believed to be flat; nevertheless from around the fifth century bc there were varying opinions suggesting that the Earth was actually round and calculations were conducted to measure its radius. Particularly from the seventh century ce onwards, the number of studies regarding what the Earth really looked like have increased tremendously.¹

In later years, with the advent of Islam and its open encouragement of Muslims to explore the universe and make advances in science, Muslim scholars made huge progress in astronomical research. Historians who have studied these advancements in astronomical science agree that the era between the eighth and fourteenth centuries can aptly be designated as a period of Islamic astronomy. In the years following the sixteenth century, significant research was undertaken in relation to the shape of the Earth and measurements of its radius in both the Islamic world and the West.

In the eighteenth century astronomic research and the advancement of technology proved not only that the Earth was round, but that it had a distinctive shape. According to calculations, the Earth was bulging around the equator and flattened at the poles. The maps produced by satellite systems show that the Earth is not completely round or smooth, but rather it has protrusions, creating an uneven surface that resembles a face with spots.2

“Geoid” is the term scientists prefer to use when referring to the physical depiction of the Earth’s surface. The shape of the Earth is not a perfect ellipsoid, thus, scientists use this representative surface that is thought to be most approximate to sea level, in order to identify departures from the ellipsoid shape. Due to the events of nature and human-related factors the geoid constantly changes, and this is why a precise mathematical account of the geoid has not yet been possible.

The Earth is known to be a geologically active planet. Just as everything else in the universe, from atoms to galaxies, has not been left to their own fate, the Earth is also constantly being transformed, thus making our magnificent ecosystem possible. The continuous geological process of changes in the Earth’s crust is related to a variety of factors: the varying density of the rock layers which form the Earth’s crust, the activity of the tectonic plates, as well as the movement of the continents, shifts in the center of gravity, tidal activity, hydro-spherical and atmospheric phenomena, and human intervention in some regions.

Researching the variations in the gravity of the Earth with satellite systems is a relatively new method of recording the changes in geoid elevations. The distance between the center of the Earth and its surface is constant (the tallest mountains will rise or decrease 1-2cm per year at most); if we take into consideration that the Earth’s physical body does not vary much and disregard the other forces, then we can say that the main reason for these infinitesimal changes in gravity on the surface of the Earth is due to differences in mass. While there is a decrease in weight in specific regions from melting glaciers, in other areas there is an increase in weight due to melting water flowing into reservoirs; both these phenomena play a significant role in the variations of the Earth’s gravity.

Even a minor variation in mass can be detected by measuring gravity. The change of mass location on the Earth’s surface results in gravity variations in the same region; in brief, today the commonly used gravity measurements are the most important source for detecting and identifying variations in geoid elevations, as well as determining the actual reasons for these changes. Gravity measurements are conducted via satellite systems; these indicate changes in mass location by detecting an increase or decrease in weight. The most modern technological satellite systems that can detect gravity change and allow us to follow the variations in masses on the Earth’s surface are the satellite used by the European Space Agency, called GOCE, and NASA’s satellite, called GRACE. GOCE has been designed to perform accurate studies of the Earth’s gravity field as it progresses into orbit. As the satellite passes over the regions where gravity is intense or weak, it measures the variations in gravity with signals that have been conveyed by a device called a gradiometer. GRACE is a pair of identical satellites that are flying in the same orbit, 136 miles apart; they orbit the Earth at a distance of 300 miles. These satellites can measure distances with microwave signals, and can detect changes of less than 1% the thickness of human hair; thus the twin satellites are able to accurately measure the distance to the surface of the Earth. The measurements provided by this satellite system make it possible for changes in gravity to be calculated. The GRACE satellite data is 1,000 times more accurate than other gravity field detection systems.

The enormous waves that occurred on the sea surface as a result of the Sumatra Island earthquake, which measured 9 on the Richter scale, caused a level ridge, measuring about six meters in height, to form on the shore. According to data produced by GOCE, such changes in the mass of the Earth’s surface caused a variation of 18 mm to occur on the geoid; this is recognized as a relatively high degree of change.

Changes in the polar glaciers also cause variations in the geoid; data provided from satellite GRACE shows that the layers of ice in Greenland and the Antarctica are melting at a higher rate than previously expected. The melting icebergs are causing a rise in sea levels of up to 0.41 mm every year and the weight of water produced from the melting icecaps is causing changes to the shape of the Earth’s surface.3

One of the interesting facts attained by GRACE is the changes in the Earth’s gravity field that have been caused by Three Gorges in China, the largest reservoir ever built. The lake region of the reservoir that is being built measures around 372 miles long, 70 miles wide and approximately 574 feet deep; when the casing of the reservoir is completed it will house an amazing 39.3 billion m3 (9.4 cu mi) of water. The area that this reservoir will cover once the project is completed is so great that it will make an estimated 1.5 million people homeless. It has been observed that the enormous accumulation of water in the completed sections of the reservoir has increased the gravity level in that region, which in turn has caused changes in the geoid structure.4

Scientists have confirmed that the Earth’s shape is becoming rounder as a result of the construction of projects like the Three Gorges reservoir. It is also estimated that the weight decrease due to the melting icecaps has played a major role in these changes. In some regions of Scandinavia and Canada the ground is rising 1 cm every year due to the melting glaciers. The water produced from the melting glaciers is forcing the currents in the Atlantic Ocean towards the equator, while the decrease of mass at the poles and the increase of weight in the equator region have caused significant changes in the shape of the Earth.

Many scientists claim that changes in the Earth’s surface have been caused by changes in the climate. Unfortunately, according to a report published by the UN Intergovernmental Panel on Climate Change (IPCC), humans are responsible for 90% of global warming. As a result of these vast variations, the geoid shape of the Earth is becoming rounder and its radius is increasing annually by 0.4–0.8 mm. The reasons for these changes are being closely monitored by scientists. According to scientists, the variation of the geoid that has been caused by changes in mass location is having an effect on the Earth’s dynamics, with the transfer of mass demonstrated by the changes in gravity causing a reduction in the speed of the Earth’s rotation around its axis; this is expected to result in variations in the daily time-zone.

Abdullah Sancak is pursuing an academic career in engineering in Turkey.

Notes

1. For more information on this topic see James R. Smith, Introduction to Geodesy, The history and Concepts of Modern Geodesy, John Wiley and Sons, Inc., 1997.
2. There are interesting images that show how the earth looks in the following link: University of Texas Center for Space Research and NASA (7 Haziran 2005) http://www.csr.utexas.edu/grace/gallery/gravity/
3. G. Ramillien, A. Lombard, A. Cazenave, E. R. Ivins, M. Llubes, F. Remy, R. Biancale, Interannual variations of the mass balance of the Antarctica and Greenland ice sheets from GRACE, Global and Platenary Change 53 (2006) 198-208.
4. San Shaoan, Institute of seismology, CEA, Wuhan, China, Gravity change before and after the first water impoundment in Three Gorges Project. http://www.sgg.whu.edu.cn/icct/html/icct_ppt/S1/sun.s.A___fourth.pdf