Tag: medicine

Posted in Psychology & Medicine

Scrubs

Posted on by Jinavie

Scrubs is the uniform that surgeons, anaesthetists, emergency department doctors and nurses wear for the freedom and mobility required in activities such as surgery and CPR. Also, since it is owned and washed by the hospital instead of being privately owned, it is more hygienic and helps prevents infections. A noticeable trait of scrubs (and also surgical gowns) is that almost every hospital uses a shade of blue or green instead of white. Why is this?

The reason being, looking at a surgical scene for a long period of time can cause eye fatigue and afterimages due to the redness of blood and organs. Afterimage is a phenomenon that occurs when the retina becomes insensitive to a strong colour and instead making the complementary colour stand out more. Ergo, a surgeon looking at blood and organs for too long will see afterimages of a blue shade, which may cause accidents to happen as it overlaps on white surfaces or the surgical field. Clothing of blue or green colour neutralises the afterimage and is much easier on the eyes, reducing the fatigue. Lastly, blue-green colours have a calming psychological effect, which helps in a high-tension, stressful environment such as in an operating theatre.

Posted in Science & Nature

Fighting Fire With Fire

Posted on by Jinavie

On a hot summer’s day, one tends to drink cold drinks and eat cold foods to try cool their body down. But an old Korean proverb states that one should control fire with fire (yiyul-chiyul, 이열치열, 以熱治熱). In other words, instead of drinking cold drinks, it is better for your health if you eat hot soup to combat the heat. When the temperature becomes hot, the body redirects blood flow to the skin to cool itself, meaning there is less blood flow to the organs and causing the internal temperature to drop. Although cooling yourself is good, having a cold drink rapidly on a hot day can suddenly cause a large temperature difference between the surface and the organs, leading to digestive problems. In severe cases, it can cause abdominal pain and diarrhoea, with a vicious cycle where the heat is trapped on the surface and you feel even hotter. Ergo, having a hot food like samgyetang (a Korean chicken soup with many nutritious foods to revitalise your health in the summer) warms the organs and allows for better communication between the organs and the skin to effectively overcome the heat.

The philosophy of yiyul-chiyul can be extended beyond the scopes of medicine. Just as the proverb defeat savages with savages (yiyi-jeyi, 이이제이, 以夷制夷) says, one can control a certain force by using the same force on it. A great example is backfires. A forest fire tends to be too large in area to be extinguished with water. But if you deliberately start a fire just beyond its trajectory, it will burn everything as it moves towards the forest fire. Eventually the two fires will meet and without any fuel to consume, both will be extinguished.

Posted in Psychology & Medicine

Pica

Posted on by Jinavie

Occasionally, there are news stories about a man who eats steel or a girl who likes to eat plastic. Such a condition where the person develops an appetite for a non-food substance is called pica. Pica is more common than one would think. The most common cases are those of dirt, clay and chalk, with the disorder being much more prevalent in children or pregnant women. Although pica is officially a mental disorder (possibly related to OCD), it is possible that it is a neurological mechanism to cure a certain mineral deficiency. For example, patients with coeliac diseases or hookworm infections tend to be iron-deficient and the substances they eat tend to contain iron. It is unclear how the brain knows what “food” to eat to cure a disease, but there are many cases where people subconsciously consume foods that would improve their health. According to a study, between 8% and 65% of people have had a sudden urge for a very strange appetite. However, as substances commonly involved in pica (such as dirt and ice) are solids, they can damage the oesophagus and the digestive tract. Also, they may contain toxic chemicals which can cause poisonings, making pica a potentially dangerous condition.

Posted in Psychology & Medicine

Time Perception

Posted on by Jinavie

What exactly is the present? The present is the middle point between the past and future, the world that we experience and perceive on a real-time basis. But would you believe it if the world you perceive is not the true “present”? To experience the world, we use our five senses. The brain collates all these sensory information and processes it to construct “the present”. This process takes about 80 milliseconds. Ergo, the world we experience is actually the world as it was 80 milliseconds ago. For a similar phenomenon, consider the stars. The stars we observe are not what they look like now, but what the stars looked liked when they emitted the light that we see. Thus, the star you are looking at may not even exist anymore.

But 80 milliseconds is a very short time; surely it has no impact on our everyday life? To prove that this delay has a critical impact on our understanding of cause and effect, neuroscientists designed the following experiment. The researchers would ask the participant to press a button that caused a light to blink after a short delay. After about ten tries, the participants reported that the delay had disappeared and the light flashed immediately after they pressed the button. This was due to their brain editing out the time delay and directly connecting the cause (button) and the effect (flash). But a much more peculiar phenomenon was seen when the researches removed the delay between the button press and the flash. Participants reported that they saw the light flash before they even pressed the button. The participant’s brain had become so used to the editing process that it was confusing the order of the cause and the effect.

The brain’s time-editing ability can be seen in the following simple experiment. If you touch your nose and toe at the same time, logic dictates that as the toe is further from your brain, the signal will have to travel further and it will be felt later. But in reality, you feel both at the exact same time. This is because your brain uses a map of the body to edit the relative time the signal takes to reach the brain to better construct a “real-time present”.

Posted in Psychology & Medicine

How To Feign Death

Posted on by Jinavie

Usually to check if a person is dead, one checks their pulse and breathing. If you want to fake your death properly, you must be able to stop both of these. You can easily hold your breath, but how can one stop their own heart? The answer lies in a ball.

If you wedge a tennis ball, squash ball, baseball or any small but firm ball in each of your armpits and squeeze tightly, the pulse at your wrist will disappear. This pulse is the radial pulse, and the radial artery is a branch of the brachial artery further up the arm. If a ball is squeezed in the armpit, it compresses the brachial artery, stopping the blood flow to the radial artery and obliterating the radial pulse. Most people who are not medical professionals tend to use the radial pulse for taking a pulse, so this method can be used to make it look like you do not have a pulse. But as this trick only causes the radial pulse to disappear, it is ineffective if the other person takes the pulse at another site such as the carotid artery or femoral artery. However, if you can control the situation and the person checking to see if you are alive is not a doctor or nurse, then it is quite a useful trick to use.

Posted in Psychology & Medicine

Nostril

Posted on by Jinavie

What would happen if your nostrils were facing up instead of down? Rain would fall into your nose and when you were sad or with a cold, mucus would fill up in the nose instead of draining, creating quite a problem. Then why do we have two nostrils? The reason being, if one is blocked, we can breathe through the other (unless you have bad hay fever or a cold and both are blocked). This shows how (almost) every part of the human body has a purpose, including its shape and characteristics.

Another fun fact about nostrils is that at one moment, only one nostril is used for breathing. In other words, you can breathe easily through one side of your nose but the other side will feel stuffy and blocked. This phenomenon alternates sides on a periodic cycle (where the blocked side becomes clear and vice versa). This mechanism is most likely to protect the inside of your nose (nasal cavity) from drying out.

Posted in Psychology & Medicine

Muslin Disease

Posted on by Jinavie

The French Revolution that occurred in the late 18th century had a significant impact on not only politics, but French society as a whole. Even after the revolution, there was much hatred against the nobility and especially the luxurious and extravagant lifestyle they lead. Men and women wearing too much clothes and jewellery were punished heavily. There was even a law stating that the weight of your clothes and accessories combined must not exceed 3.5kg. In the early 19th century, the fashion trend changed from the fancy dresses of the past with many decorations to a much more simple, clean and frugal type of dress. A point of interest is that women wearing petticoats (an undergarment worn to puff out skirts) – a key point of the Rococo style – were executed on the guillotine, causing women to quickly throw away their petticoats and try to look as slim as possible. To look thin, women did not even wear underwear. There was a fabric that suited this new fashion trend very well and that was the extremely thin cloth, muslin.

But to follow the fashion of then, it is not enough to simply wear a muslin dress. In early 19th century France, the trend was to douse your dress in water. Why did the women drench themselves in water? The reason being, muslin is a very thin and light cloth that becomes half transparent when wet, while clinging to your body. Women dampened their muslin dress to prove that they were wearing nothing underneath. Also, the ideal, beautiful woman of the time was an intellectual woman who looked fatigued from reading books all night long. Drenching yourself in water adds to this gaunt image, accentuating your fatigue and by extension, your beauty. The woman probably also intended to make the clothing cling to their body to show off their figure (much like the modern day wet t-shirt contests).

The problem was that muslin is an extremely thin material that is unsuitable in the winter or in Northern regions. Considering that women were wearing such a thin dress and even pouring water on themselves, one can imagine how cold they must have been. In fact, France suffered a heavy epidemic of pneumonia in the early 19th century with as much as 60,000 patients turning up with pneumonia every day. A high proportion of these patients were women who liked to wear wet muslin dresses. Thus, the pneumonia was nicknamed muslin disease.

Posted in History & Literature

Elements: Yin And Yang

Posted on by Jinavie

Yin-yang is a frame of thinking that can be considered a fundamental basis of Eastern philosophy. In ancient Far East Asia, people categorised everything of nature as yin or yang, including natural phenomenon such as human physiology. Yang(陽) is a masculine element, yin(陰) is a feminine element and the two represent the countless symmetries found in nature. Just as there is a sky for the earth, a sun for the moon, a man for a woman and strength for softness, every phenomena in human societies and the universe can be identified in relative terms. The concept of reducing these to a plus and a minus to explain natural events is the concept of yin and yang.

For example, consider a hill in the sunlight. The bright side is called the “yang place” and the opposite, dark side is called the “yin place”. Thus, light is yang, darkness is yin. That is not all. The air that is heated by sunlight becomes warm and rises, while cold air sinks because it is heavy. Yang symbolises heat, lightness and upward, active movement while yin symbolises cold, heaviness and downward, sluggish movement. But that does not mean that yin is bad and yang is good. The reason being, everything that counters each other in nature coexists and forms a balance. Also, as time passes, the sun will move from the east to the west, making the sunny place dark and the dark place sunny. Yin-yang is a law that shows the relativity of nature very well. It shows that everything is relative to each other even if they seem like opposites, forming a harmonious balance and cycle.

Balance forms harmony and nature always seeks harmony. For example, traditional Korean and Chinese medicine is based on the concept that the reason why diseases occur is because of the balance of yin and yang in the human body being broken. To restore the balance, acupuncture and herbal remedies are used, restoring good health. A broken harmony is due to one side being greater than the other as yin and yang form a zero-sum game. This means that as one side waxes, the other side wanes and vice versa, with the sum of the two being equal at all times. But this does not mean that yin and yang oppress and fight each other. Instead, the two rely on each other despite being opposites. In this world, there is no light without darkness. There is no forwards without backwards and no life without death. For instance, if there were only men (yang) in this world, the human race would be wiped out in one generation. But if yin and yang coexist to help each other and form a union, they give birth to a new generation. Nature always exists as a perfectly balanced coexistence of two polarities. When yin and yang form a balance they form something even greater than their sum, which is harmony.

1 + 1 = 3

(Image source: http://falynevarger.deviantart.com/art/Yin-Yang-Dragons-119779525)

Posted in History & Literature

Elements: Four Elements Of The West

Posted on by Jinavie

Human beings have believed that all matter can be divided into basic elements for a very long time. Although we now know that the basic building block of the universe is atoms, what did ancient people believe matter was made of?

In ancient Greece, the seat of Western culture, it was believed that everything was made from the four elements: earth, fire, water and air. According to Aristotle, every element has a primary and secondary characteristic, with the four characteristics being hot, cold, dry and wet. Air is primarily wet and secondarily hot, fire is primarily hot and secondarily dry, earth is primarily dry and secondarily cold and water is primarily cold and secondarily wet. He also spoke of a fifth element (quintessence) beyond the four elements. The name of the fifth element is aether and it is a pure and heavenly element that cannot be corrupted like the earthly four elements. Furthermore, it was thought that aether was the element of the sky and stars were composed of it as they were heavenly, not earthly.

The four classic elements of ancient Greece had an impact not only on physics and chemistry, but also on philosophy and culture (the concept of the four elements is popular in modern games too). The most interesting example of these is a theory by Hippocrates, the father of Western medicine, that states that the human body is composed of four bodily fluids (humours) and an imbalance between the humours caused diseases. The four humours are yellow bile (fire), black bile (earth), blood (air) and phlegm (water). Furthermore, he believed that the four humours affected personalities too. For example, an excess of black bile (“melan chole” in Greek) would cause a person to become introspective and think negatively, leading to depression or “melancholy”. This is quite possibly the first medical records on clinical depression.

The four classic elements of ancient Greece can also be found in ancient Egypt and many other ancient civilisations. It also had a significant influence on alchemy in the Middle Ages.

(Image source: http://y3rk0.deviantart.com/art/The-Four-Elements-87598175)

Posted in Science & Nature

Chalkboard

Posted on by Jinavie

The sound of fingernails scratching a chalkboard is one of the most difficult sounds to listen to. This “screech” sound gives the sensation of your soul being ripped to shreds and invokes great discomfort. Why is this?

Professor Randolph Blake of Vanderbilt Center, USA, observed that this sound is very similar to the scream chimpanzees and macaque monkeys make when they see a predator. According to other researches on this phenomenon, many species of monkeys also hate this sound greatly. Blake used these facts to hypothesise that as our primitive ancestors used this sound to alert an enemy approaching, it has been programmed into our primitive brain to trigger a negative response. Also, physically this sound amplifies in our ears at a certain frequency to cause intense pain. The pain and our basic instincts combine to generate such an unpleasant feeling.