Posted in Psychology & Medicine

Scrubs

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 Psychology & Medicine

How To Feign Death

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

Pulse

Blood, which supplies all the cells in the human body with nutrients and oxygen, flows through the vessels due to the pumping of the heart. Thus, blood flow directly transmits the force generated by every heartbeat. As the blood ejected by the heart causes the arteries to “pulse” by stretching and relaxing. As some pulses can be felt over the skin, they are very useful in patient examinations, especially a clinical exam of the cardiovascular system. Although people commonly know how to take a pulse from the wrist or neck, there are many more places a pulse can be taken from.

  • Radial pulse: Taken from the inside of the wrist on the side of the thumb.
  • Brachial pulse: Taken from the inside of the elbow.
  • Carotid pulse: Taken from where the neck meets the jawline, or 2~3cm either side of the Adam’s apple to be precise.
  • Apex beat: This measures the heartbeats directly, taken on the left chest between the 4th and 6th ribs (around the left nipple).
  • Abdominal pulse: Taken from above the belly button of a lying patient, may be able to see the pulse.
  • Femoral pulse: Taken from the middle of the groin. 
  • Popliteal pulse: Taken from the inside of the knee.
  • Posterior tibial pulse: Taken from the inside of the ankle behind the bone.
  • Dorsalis pedis pulse: Taken from the back (upper side) of the foot along the middle.

When taking a pulse, you use your second and third fingers (and the fourth if you want) and press lightly on the pulse point. If you press too hard, you may stop the blood flow and obliterate the pulse. As a pulse is measured per-minute, it is often taken for 10 or 15 seconds and multiplied by 6 or 4 respectively. Also, it should be noted whether the pulse has a regular rhythm, and if it is irregular, whether it is regularly irregular or irregularly irregular. If the pulse is over 100 beats per minute, it is called tachycardia, while less than 60 beats per minute is referred to as bradycardia. If it is irregular, it is called an arrhythmia.

An experienced doctor can diagnose different conditions such as an aortic stenosis or atrial fibrillation just from taking the pulse of the patient. Taking a pulse is also a crucial diagnostic tool in traditional Korean and Chinese medicine.

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Posted in History & Literature

Whaling

The Faroe Islands are a group of islands between Scotland and Iceland in the North Atlantic Ocean. Although a small nation, they are known to the outside world for their tradition of whaling – specifically pilot whales that are native to the North Atlantic Ocean. The media often show photos of bloody shorelines with a line of whale carcasses, decrying the so-called “inhumane hunting” of the whales. The dramatic scene and cuteness of the whales seems to appeal to the masses and has caused quite a controversy regarding the Faroese tradition, known as grindadráp. However, the media often tells a misinformed story regarding the whaling. One thing to know is that Faroese whaling is fundamentally different to whaling seen in other parts of the world, such as Japanese whaling. 

The Faroese have been killing pilot whales for food for the past millennium and have done so in the most humane and sustainable way possible. Despite popular belief, the pilot whales are not endangered and in fact overpopulated in the North Atlantic Ocean. As they are carnivorous, an overpopulation of the whales causes a shortage in fish. Fishing is the major industry in the Faroe Islands and constitutes their livelihood; so ironically, the pilot whales can endanger the Faroese people by consuming all the fish in the surrounding sea. Thus, the Faroese kill a small portion of the whale population (roughly 0.1%, a completely sustainable rate) to balance the ecosystem while protecting their most important industry and their livelihood.

Faroese whaling is not commercial and only enough whales are killed to provide enough food for the people (equally distributed to the participating families). The killing is not for fun or money, but simply to support the lives of the people. As such, the Faroese have also come up with the most humane way to kill the animals.

When whaling season starts and the pilot whales come near the shore, “drives” are initiated where a semi-circle of boats herd nearby whales towards the shoreline (only whales near the shoreline are killed). When the whales approach the shore, the people use blunt blowhole hooks that catch the whales without causing wounds (unlike harpoons and spears) and draw them closer to shore. Only adult males are drawn in (no females or babies) and only enough that can be killed swiftly are drawn in.

Once drawn in, the men quickly use their knives to cut the spinal cord and artery supplying the brain, killing the whale within 15 seconds of being beached. It is the quickest and most painless way to kill the whales and only those who have been trained to do it properly are allowed to kill. As a major artery is cut and whales are big mammals, a large volume of blood is released, dying the sea a bloody red colour.
The whales are then divvied up equally, with no part of the whale going to waste. As only nearby whales are killed, sometimes no whales are killed for years.

Unfortunately, due to pollution in the ocean, there have been increasing levels of heavy metals such as mercury found in the whale meat. This is endangering the health of the island population and the deeply engrained tradition of grindadráp. The saddest part is that the pollution is from industrialised countries such as USA and European countries, not the Faroe Islands. Yet the Faroese have to put up with bigotry from those who do not understand the culture, process or the reasoning behind the tradition. If anything, it is by far more humane and sustainable than killing animals after a lifetime of captivity then sending them to a slaughterhouse.

It is extremely important to see the truth behind controversial issues such as this, as more often than not the truth is shrouded by bigotry and subjective comments by people who have only seen the issue through some photographs on the internet.

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(Notice the single, deep horizontal slash through the dorsal aspect of the spinal cord, just before the brainstem. Such a cut would immediately sever any pain signals and cause almost instant unconsciousness due to ischaemia of the brain.)

Posted in Psychology & Medicine

Stroke

A stroke is caused by a disruption in the supply of blood to the brain, which leads to cell death as oxygen is required. There are two types: ischaemic (where a clot cuts off blood supply to an area of the brain by blocking an artery) or haemorrhagic (when a blood vessel ruptures and leaks blood instead of delivering it to tissue). The most common cause of a stroke is a clot that made its way up to carotid arteries into the brain until it wedges in small vessel. There are many risk factors for blood clots, such as smoking, high cholesterol levels, atrial fibrillation and long distance flights.

Because the brain is always in high demand of oxygen (taking 20% of the total oxygen available), strokes can produce devastating effects within minutes. 5 minutes of oxygen deprivation can lead to irreversible cell death, a principle that is also used in cases of shock, where the blood pressure is too low to supply organs, or cardiac arrest. Therefore, it is crucial to recognise a stroke early so that an ambulance may arrive and deliver clot-busting medication such as streptokinase.

The FAST mnemonic is an effective way of remembering the common signs of a stroke. It is also useful in reminding people to respond fast.

  • F – Facial weakness: Is the person’s smile crooked? Disrupted brain function causes facial weakness on the opposite side. The weakness is usually seen around the mouth or eyes.
  • A – Arm weakness: Can the person keep both arms outstretched? This is related to motor function of the brain.
  • S – Speech difficulty: Is the person’s speech slurring or are they having problems understanding speech? This is a combined result of impaired motor function and speech centres of the brain.
  • T – Time to act: Call an ambulance. NOW.

Posted in Science & Nature

Badass Weapons Of Nature: Long-tailed Weasel

Long-tailed weasels are ferocious predators found in North America that likes to stalk its prey and pounce it with lightning speed. With small prey such as mice, the weasel will wrap its long body around the prey and then crush the head with a strong bite. As the weasel is very slender and sleek, it can easily dig into burrows to hunt hiding animals by crushing its skull, or to add variety, ripping out the windpipe.

Although it usually preys on small rodents, the long-tailed weasel is also known to fearlessly attack much larger animals such as birds and rabbits. As wild rabbits tend to be bulkier (sometimes even ten times larger) than the weasel, it cannot use its characteristic hunting style. To overcome this difficulty, these weasels have developed a strange behaviour that zoologists have labelled the Weasel War Dance. The War Dance (NB: two videos on what it looks like) is a chaotic set of movements where the weasel runs left and right frantically, jumping and flipping upside-down and almost appearing insane. This type of behaviour is observed in other species of weasels and ferrets when they are excited, but few use it as a hunting tool.

It has been observed that when the long-tailed weasel performs a War Dance in front of a rabbit, the rabbit becomes dazed and enters a trance-like state. It is possible that the chaotic and confusing movements disorient the rabbit. Once the rabbit has been disabled, the weasel promptly jumps on the rabbit’s back and delivers a powerful bite to the back of the neck, instantly killing the rabbit.
Wild weasels and stoats practise this skill by playfully ambushing each other when they are young.

Long-tailed weasels, despite their cute appearance, are notorious for their vicious temper. Being a carnivore that prefers fresh meat, it actively hunts and collects food. Despite seeking fresh food, the weasel also exhibits a curious behaviour of storing carrions, which is often only eaten in times of food shortages. This behaviour leads to the weasel going on killing sprees just because they can. Long-tailed weasels have also been observed lapping up blood from the wounds they inflict, and enjoys making their nest from the fur of their victims.

Posted in Psychology & Medicine

Insulin

Diabetes is a common and serious disease that is caused by the body being unable to control the blood sugar (glucose) level, leading to severe organ damage. For example, blood vessel damage can lead to blindness, renal failure, heart attacks or strokes. Diabetes is divided into Type 1, caused by the destruction of pancreatic β-cells (that produces insulin) leading to insulin deficiency, and Type 2 diabetes, where insulin resistance renders the hormone useless. Thus, diabetes is a disease related to insulin. So what is insulin?

Insulin is a hormone that lowers blood glucose. It has the important function of controlling blood glucose levels after a meal. Therefore, a diabetes patient has high blood glucose, which has a toxic effect.
As type 1 diabetics cannot produce insulin, they require daily insulin injections. Some type 2 patients also need insulin. But this hormone that saves the lives of diabetics also has a deadly dark side.

Too much insulin leads to hypoglycaemia due to its blood glucose lowering properties. This is the opposite of what happens in diabetes, but is even more dangerous. Although there are in-built autonomic defence mechanisms to prevent this from happening, a high level of insulin can overcome this to cause blood glucose to plummet. 
A hypoglycaemic patient initially suffers cognitive dysfunction, then sweating and tremors. As blood glucose falls further, the patient begins to convulse, until they fall into a coma and eventually die. This is because the brain heavily relies on glucose for its functions, and a disruption of glucose supply causes it to shut down.
Because blood glucose fluctuates much like blood pressure, it is hard to control. This leads to many diabetics accidentally falling into hypoglycaemia, or even losing their lives. Furthermore, insulin is sometimes used by people to cause hypoglycaemia as a means of suicide.

If you see a person convulsing, check around for any hypodermic needles or bottles of insulin. A diabetic patient would have a medic alert bracelet, and if it is a suicide attempt they would have recently injected themselves with insulin. If you think it is hypoglycaemia, you must immediately treat the patient as severe complications can occur in a very short time. The emergency treatment is quite simple – raise the blood glucose. For example, dissolving a spoon of white sugar in the patient’s mouth or making them drink a sugary drink such as apple juice can cause a spike in blood glucose, causing the symptoms to disappear. If their consciousness does not return, you may need to repeat the process until their blood glucose is high enough.

Knowing even a little about insulin and hypoglycaemia may lead to you saving a person’s life someday.

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Posted in Science & Nature

From Cell To Birth: Childbirth

The onset of labour signals that the birth of the child is imminent. Strong contractions of the uterus under the influence of oxytocin cause intense pain for the mother. This escalates as oxytocin creates a vicious cycle for more and more powerful contractions. Other signs include a bloody show, where blood and mucus leaks out, and the water breaking, where amniotic fluid bursts out as the membranes rupture.
When the cervix has fully dilated to 10cm wide, the baby is ready to come out, and this is the end of the first stage. It may take over 24 hours for this stage to be over – all the while the mother is in extreme pain as her body transforms for the process.

The second stage concerns the delivery of the baby, and follows a precise series of steps.

  1. The baby, oriented head-down, facing either right or left, leans against the pelvis.
  2. The baby begins to descend, passing through the pelvis.
  3. It flexes its head as it comes through the cervix, turning towards the mother’s back as it does so.
  4. As the head crowns, the baby turns back to its side-facing position so the shoulders can come out.
  5. The rest of the body comes out with the shoulder. Forceps may be used to help.

The passage of such a large head and body is only possible through the massive dilation of the cervix, the stretch of the vagina, and the soft, malleable skull of the baby (a newborn’s head often looks conical and alien-shaped). Quite often, the opening of the vagina is not wide enough, and the opening may be cut open more to ensure it does not rip.

After the baby is safely delivered, the umbilical cord and the placenta are also delivered, thus ending the third stage (afterbirth). The cord is clamped and cut, and the baby is then thoroughly checked to ensure it is healthy and has no developmental issues.

Although in the past childbirth was extremely risky and often led to the death of the mother and/or baby in the process, nowadays protocols and health professionals ensure that both survive the procedure, thus ending the incredible 40-week journey until the birth of a new life. Only after understanding the arduous steps and the risks a mother takes to give birth to her child can one truly appreciate the value of life.

(Full series here: https://jineralknowledge.com/tag/arkrepro/?order=asc)

Posted in Psychology & Medicine

Cranial Nerves

Nerves can be divided broadly as spinal nerves and cranial nerves: the latter which is directly from the brain. There are 12 pairs of cranial nerves:

  1. CN IOlfactory nerve (smell)
  2. CN IIOptic nerve (sight)
  3. CN IIIOculomotor nerve (eye movements, control of pupil and lens)
  4. CN IVTrochlear nerve (eye movements)
  5. CN VTrigeminal nerve (sensory information from face and mouth, chewing)
  6. CN VIAbducens nerve (eye movements)
  7. CN VIIFacial nerve (taste, tear and salivary glands secretion, facial expressions)
  8. CN VIIIVestibulocochlear nerve (hearing and sense of balance)
  9. CN IXGlossopharyngeal nerve (taste, swallowing, parotid gland secretion, sensory information from oral cavity, information about blood)
  10. CN XVagus nerve (sensory and motor signals to and from many internal organs, glands and muscles)
  11. CN XIAccessory nerve (movement of SCM and trapezius, which are neck/shoulder muscles)
  12. CN XIIHypoglossal nerve (tongue movements)

As there are so many nerves and the names are all varied, there is a simple (yet very obscene) mnemonic to help medical students remember the names and order of nerves:

Oh, Oh, Oh, To Touch And Feel Virgin Girls’ Vaginas And Hymens
or
Oh, Oh, Oh, To Touch And Feel A Girl’s Very Soft Hands
(where vestibulocochlear -> auditory)

It is also worth noting the mnemonic for the types of nerves is:

Some Say Marry Money, But My Brother Says Big Boobs Matter More

Perhaps the only way to survive medical school is through humour.

Posted in Science & Nature

Matador

The word “Spain” often brings upon an image of a handsome matador taunting a fierce bull with his red cape. Because of this, it is commonly thought that the colour red aggravates bulls, and this is often used in cartoons.

However, as bulls are colour blind, they cannot tell a red cape apart from a blue cape. They are actually responding to the movement of the cape and being provoked by the matador. Furthermore, the bulls used in bullfights tend to be a more aggressive breed. This type of charging behaviour is common in large herbivores such as hippos, rhinos and elephants, as it is very useful in nature when faced with a predator.

Also, the real reason the cape is red is not only because it symbolises passion and power, but because it also hides the blood from the bull during the fight.