Smart Blog for Smart People


    Why do bruises change color several times before disappearing? Why do they turn red or crimson, or even yellowish green? Why do they often appear a day or two after a bruise?

    A bruise forms as a result of rupture of small blood vessels (capillaries) under the skin. The hemoglobin of the spilled blood gives the bruise a classic dark crimson color. Then white blood cells surround the site of damage and cause the destruction of red blood cells, which contributes to the appearance of substances responsible for color change.

    Hemoglobin breakdown products are biliverdin (green bile pigment) and bilirubin (yellow-red bile pigment). Later, the decay products at the site of the injury are removed, and the color disappears. This process is similar to the process of getting rid of “aged” red blood cells. White blood cells, called macrophages, break down dead red blood cells in the spleen, liver, bone marrow, and other tissues. Bilirubin is absorbed by the liver, where it turns into bile and takes part in the digestion of food. It is bilirubin that gives the decay products a characteristic color.


    Is it true that the darker the color of the alcoholic drink, the harder the hangover. Whiskey, red wine or brandy will cause a more severe hangover than vodka or white wine, because darker drinks contain so-called congeners.

    Most people drink alcohol because of the ethanol they contain. However, they contain other congeners - biologically active components. The composition of congeners includes complex organic molecules (polyphenol), other alcohols (methanol) and histamine. They are formed along with ethyl alcohol in the process of fermentation, or ripening, of an alcoholic drink. It is believed that congeners are responsible for the effect of intoxication and subsequent hangover. People who drink alcohol based on pure alcohol (such as vodka) are less likely to suffer from hangover symptoms than those who drink darker alcoholic drinks (whiskey, brandy, red wine), in which the content of congeners is much higher.

    The main culprit of the hangover is the methanol congener. The human body absorbs methanol in the same way as ethanol, but the final products are different. Ethanol produces acetaldehyde, and the breakdown of methanol produces mainly formaldehyde. It is more toxic than acetaldehyde, and in high concentrations can cause blindness and even death. Ethanol slows down the process of methanol breakdown, therefore, it is possible that "sober" mitigates the symptoms of a hangover. As it was revealed during the studies, according to the severity of the hangover caused, alcoholic drinks can be arranged as follows (in descending order): brandy, red wine, rum, whiskey, white wine, gin, vodka, pure alcohol.

    HIGH Forehead Why does a

    person need an eyebrow?

    With the help of our amazingly moving eyebrows, we convey our feelings. The position of the eyebrows gives the person a certain expression, and others get an idea of ​​his mood. Eyebrows help to understand whether a person is friendly or better not to approach him in order to avoid trouble. There are different types of smiles. Some express fun or satisfaction, others express deceit, gloating, and even anger. The position of the eyebrows on the forehead allows you to judge the feelings and mood of a person.

    Eyebrows play an important role in expressing feelings. Perhaps the most important is the movement of the eyebrows, such as bouncing - quickly raising and lowering the eyebrows, expressing understanding or approval. In ancient times, the ability to transmit friendly intentions from a safe distance, of course, helped our ancestors survive. The transmission of various signals by the eyebrows is a widespread phenomenon among primates, although only in humans the eyebrows noticeably stand out on the face, because the background is skin that is devoid of hair.


    How long can a person live using only beer as food and drink? And what types of beer - ale (light beer), strong porter (black beer) or soft beer - are more likely to survive?

    From time immemorial, beer has been considered the most important food product, liquid bread. In ancient Egypt, the labor of workers was paid for with beer. In England, in 1492, a gallon of beer per day was received by the sailors of the navy of Henry VII, and later on as a salary by the court ladies of Elizabeth I. Beer was brewed from vitamin-rich brewing barley, and therefore it was valued as a highly nutritious product. Beer today is considered as such. Looking at the comparative tables of nutritional value of various products, we see that a pint of beer contains more than 5% of the recommended daily intake of several types of vitamins - B9, B6 and B2. True, vitamins such as A, C and D are absent in beer.

    Of course, it is unethical to conduct an experiment to find out whether a person can survive by eating beer alone. Nevertheless, during the Seven Years' War (1756–1763), John Clefan, a doctor in the English Navy, conducted a clinical trial. Three ships were sent from England to America. A lot of beer was loaded on board one — the Grampus, and two other control vessels — the Daedalus and the Tortoise — only the standard rate for liquor. Due to bad weather, the voyage was delayed, but at the end of this unusually long journey it became clear, according to Clefan's report, that 112 sailors from the Daedalus crew and 62 from the Tortoise crew needed hospitalization. On the Grampus, on the contrary, only 13 people got sick. The result is clear.

    Of course, eight pints (4 liters) of beer per day, once a daily ration of sailors, are now not considered a moderate dose of alcohol. One can only guess about the liver condition of those sailors. No matter what they say about beer diets, eating beer alone is not the best strategy for a healthy lifestyle.

    How fat should a person be to be invulnerable to bullets? That is, what layer of fat do you need to have so that a bullet fired from a conventional pistol does not reach vital organs?

    Given the properties of the tissues of the human body, as well as the presence of protruding parts of the body - arms, legs, eyes, ears, male genital organs - it can be safely stated that the human body cannot be invulnerable to bullets. Even if the skin is thick enough to prevent the bullet from entering the body, the shock wave can seriously injure the internal organs and the network of the saphenous nerves - such is the damaging effect of a shot by a shot. A shot fired from a shotgun can kill a person without breaking through his skin.

    The depth of penetration of a bullet into the body depends on a number of factors: its lethal force, caliber, mass, shape and material from which it is made. Bullets for rifles and small arms are of various calibers - from 5 to 15 mm, their energy can be from 70 to 7000 J. The caliber of a standard police pistol is 9 mm, the initial energy of this bullet is 500 J. The penetration depth is measured by viscous shot mass. A bullet fired from a police pistol from a distance of 5 m goes into such a mass of 30 cm

    To establish the weight of subcutaneous fat of such thickness, we first calculate the surface area of ​​the body without taking into account fat. There are several formulas for calculating the surface area of ​​a body. I will use the Mosteller formula, according to which the surface area of ​​a person’s body in square centimeters is equal to 1/60 of the square root of the product of numbers expressing his height in centimeters and weight in kilograms. For example, the surface area of ​​a person’s body is 175 cm tall and weighs 75 kg is 1.91 m2. Thus, in order for this entire area to be covered with a 30 cm fat layer with a density of 1 g / cm3, a person must weigh at least 573 kg. Plus the weight of the body itself (without fat) - it turns out that a bulletproof person should have a weight of about 650 kg.


    Why, after physical exertion the next day, the legs hurt less than two days later. What is the reason for this?

    The delayed occurrence of pain in the muscles is the result of a large number of gaps in them. In an effort to perform the exercise as best as possible, we overstrain the muscles. Muscle overstrain (usually achieved with an increasing load on the muscles, for example when we lift weights or run a lot for several days in a row) causes tearing of muscle tissue fibers. During the first day after overload, we experience only mild muscle pain.

    Especially painful sensations in the muscle area arise with a sharp increase in the load on them, causing a greater number of tears in the muscle tissues - it is the number of tears that increases, and not the size of each of them. In this case, more time is spent on the formation of scar tissue, because it is formed at the site of damage perpendicular to the rupture itself. As soon as a new tissue has formed, we begin to experience more acute pain, as we reactivate and stretch this renewed, but less flexible muscle until its strength and flexibility are restored.


    Does the appendix have any functions? What is his purpose?

    The analogue of the appendix in most animals is the blind process located at the place of transition of the small intestine into the large one. As a rule, predatory mammals have a small process that plays the same role in their bodies as the appendix in humans. But in many herbivorous mammals, the blind process is noticeably enlarged, and its purpose is to create all kinds of amazing anatomical relationships. The function of the blind process in such animals is to break down complex carbohydrates that enter the body with plant food into volatile fatty acids and then absorb them as an energy source. The cecum is also involved in the process of energy production in animals such as horses, rabbits, rats, guinea pigs and pigs, in which fiber is fermented in this organ. In cattle and sheep, this function is performed by the stomach, therefore, they are less dependent on the cecum. An additional function of the blind process is the reabsorption of water from the gastrointestinal tract. In humans and carnivorous mammals, the colon performs this work.

    There was once a consensus that the appendix does not perform any function and is an evolutionary remnant, but now this view is considered obsolete. The most important function of the appendix is ​​to provide immunity to the developing embryo, but this organ continues to fulfill its purpose in the adult body, although it is not so indispensable and you can live without it. Apparently, with the help of the appendix, immunocytes detect the antigens of bacteria and other organisms living in the intestine. Thanks to this, the immune system distinguishes “friends” from “strangers” and does not destroy bacteria that coexist safely with the body. There are other bodies that perform this function. Peyer's intestinal plaques help the immune system act on the normal intestinal contents. By the time the body is growing up, the immune system is already able to independently cope with foreign substances that enter the gastrointestinal tract, and the appendix is ​​losing its significance. But the occurrence of defects in the immune space can contribute to the development of autoimmune diseases and inflammation of the intestine.

    It is interesting to note that in surgery, the appendix is ​​used as a personal "reserve material". For example, the process itself is removed, and its tissue is used during reconstructive surgery of the bladder without fear that the immune response will cause it to be rejected, as is often the case with another person’s tissue transplant.

    What is cellulite? There is a lot of information on the Internet about creams and remedies that promise miraculous getting rid of cellulite, but there is very little information about what exactly this phenomenon is.

    Cellulite, a granular formation similar to homemade cheese that accumulates mainly on the hips, abdomen and buttocks, is just a beautiful name for the subcutaneous deposits of fat bulging between the fibers of the connective tissue, which makes the skin look wrinkled like an orange peel. To check if you have cellulite, squeeze the skin of your upper thigh. If it becomes lumpy, then you have cellulite. And you are not alone in your grief. Many girls and women have cellulite, as well as some men - both young and old. The degree of damage to the body by cellulite depends on several factors. Genes, gender, fullness, age, skin thickness - all this affects the intensity of the formation of cellulite and its external manifestation.

    Whatever the reason, it’s important to know that there are no magical products, treatments, or medications that eliminate cellulite. For example, the so-called deep massage method, which some fashionable beauty salons promote as a panacea for cellulite, gives only a short-term effect, achieved by swelling of the skin. And such treatments as liposuction or mesotherapy (injections or pills that destroy cellulite) are either excessively expensive or cause only temporary improvement.

    To get rid of cellulite, you first need to get rid of excess body fat, and for this you should eat less high-calorie and fatty foods and move more. According to experts, the main tool against cellulite is a system of physical exercises, which combines aerobics and power loads. If you want to hide cellulite, use a tanning cream, because on dark skin, cellulite is less noticeable.

    Goosebumps Why does the glass “squeal” when a hand is passed

    over it?

    There are many cases where a wiping action causes high frequency resonance, and this is usually caused by intermittent friction. When one surface is shifted in contact with another, friction prevents movement, but if the shear force is increased, at some point it reaches a threshold when the friction is overcome and smooth movement begins. At this stage, the force that sets the motion of the objects decreases and both surfaces begin to slide one on the other. An elastic surface (for example, leather) deforms with increasing force. When, as a result of friction, the fingertip is decelerated on the glass, its skin under the influence of a force tending to move the finger from its place is deformed, but when it continues to slide, it again takes on almost its original form. However, changes in the surface of the fingertip cause increased friction, the skin is again deformed and the movement of the finger is instantly inhibited. With a uniform application of force, the skin surface is deformed hundreds of times per second and as a result audible sound waves arise.

    But why does friction create a similar effect? Any surfaces, if viewed under a microscope, have a rough texture, and when they come into contact, only their highest points, the so-called protrusions, really touch. These protrusions close and obstruct the movement. If you increase the force of pressure, the area of ​​true contact will increase, since any soft surface (for example, skin) is deformed, trying to come closer to the irregularities of the other surface. The frictional force that impedes movement increases. As soon as the finger begins to slip, the bulges bounce off each other and less interfere with movement.


    Is head beheading really painful? If so, how long has the severed head realized that it has been cut off?

    How long does a person remain conscious after being beheaded? In France, during the years of the reign of the guillotine, some of the prisoners were asked to blink as long as they remain conscious after a knife fell on their neck. It is reported that after cutting off the head, they blinked for up to 30 seconds, although it is difficult to say whether it was a nervous reflex or blinking occurred at the behest of the executed. In most countries where modern science could provide an answer to this question, executions by beheading have not been practiced for a long time as a legal punishment.

    To be continued…

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