Tag Archives: Human beings

Why does rain make us feel cozy?

Let’s be a bit more specific and talk about gentle rains with maybe a bit of thunder in the distance while you are indoors or under shelter. There are a large number of things that contribute.

First, the soft white noise. A gentle rain creates tons of mildly distracting pleasant white noise. This helps reduce stress.

It amplifies positive feelings of comfort, shelter and safety. You don’t get these positive feelings when you are outdoors working in the rain, you get them when the rain is not drenching you. So there is a difference between indoors (where you are comfortable) and outdoors (where you wouldn’t be). And this contrast can be bigger if there is thunder off in the distance somewhere. And such rains come when it is usually comfortably humid and cool, rather than sticky and too hot.

Gentle rains are tied to an emotional state of calmness too because they are associated with a history of calm activities and “me time”, relaxing and not working. The last time there was a day like this you pampered yourself a little with a good book on a comfortable couch… so you look forward to the next time.

Rain symbolizes renewal and cleanliness. It’s a positive source of growth for plants and it often produces a nice clean smell as it washes dust away. So there is a mental association with a few positives there.

And for those of us who live in temperate zones, this type of pleasant rain means it’s not snowing and there are leaves on the trees, and so it’s what most of us consider to be the better time of the year.

Why does gargling with salt water help with sore throat, but eating chips doesn’t?

There’s a phenomenon called ‘osmosis’ which plays its role here.

When two different liquids with different concentrations are separated by a semipermeable membrane (the one that allows one-way flow only), the liquids would flow in such a way that they attain a state of equilibrium, i.e. now the concentration of both the liquids is same.

The bacteria which cause the sore throat also have their skin similar to a semipermeable membrane. When you gargle with salty water, the inner ‘fluid’ of bacteria (which makes them live, in a literal sense) oozes out (in order to equalize the concentrations of these fluids-salt water and bacterial body fluid). This kills the bacteria and their ‘active fluid’ is washed away when you gulf-out the liquid. Thus they loose their dominance on the sore throat and you feel relaxed.

Salty food doesn’t help the way salt water does for several reasons.

For one, there isn’t enough of the right kind of salt in most salty foods to make your throat less bacteria-friendly.

Secondly, there are enough carbs and sugars in most salty foods to feed the bacteria making your throat sore. This is obviously counter-productive.

Thirdly, salty foods usually have a very rough texture which will scrape and irritate your throat, which is bad by itself but the super tiny scrapes also make great hiding places for the bacteria to grow.

So gargling salt water is a great idea and will help kill the bacteria making your throat sore. Eating salty food is a terrible idea because it basically builds a cozy place for all the bacteria to live and then gives them a bunch of free food.

How does the immune system work?

A few of the mechanisms that the immune system has to kill things are:

Antibodies. Antibodies are molecules that can “tag” things for destruction. the shape on one end of the antibody is shaped just right to catch onto a specific thing. Hopefully that thing is a bacteria or something trying to make you sick. But the antibody isn’t smart, so if it happens to be a shape that it attaches to your own nerve cells, it still “tags” them for destruction. Antibodies can also play a role in killing things through a process called agglutination. If the type of thing the antibody attaches to is free moving in the blood stream or fluid around cells, then it might bump into lots of antibodies and have lots of “tags” on it. Antibodies are shaped so that the end sticking up after “tagging” something tends to get stuck to the end of other antibodies. So, they mash together in a big mass and the things they are attached to get dragged down and die since they can’t move around and eat and breath.

Sometimes antibodies happen to be shaped in a way that they block some vital function of whatever they attach to and kill it directly, but this is less common.

Things that don’t or can’t be agglutinated though remain  “tagged” and then other parts of the immune system kick in.

Once tagged specific white blood cells come along and see the tag, which tells them to “eat” (phagocytosis) it. They do eat it and then literally they have little organells in them that digest them. These guys can only eat so much though, so they die off. That’s what the white stuff we call puss is. Dead white blood cells that ate as much of the infection as they could until they died.

For a great book on this from a genius immunologist that is extremely accessible in his writing (even funny) see In Defense of Self: How The Immune System Really Works.

Why do healing wounds feel warmer to the touch?

When you’re injured, your body inflames the area around it – basically by increasing bloodflow to that area. This allows the body to move lots of platelets to the area (to scab it over), lots of white blood cells (to fight infections), and to help repair the area and remove damaged bits.

So all the increased bloodflow to that area makes it warmer. If the warmth continues for too long, it’s a sign that the area could be infected, in which case the body is still pumping white blood cells to that area and keeping up the heat to fight off the infection.

Why does the body feel physically ill after experiencing emotional trauma?

The limbic system is responsible for this feeling. The limbic system is the emotion and memory part of your brain, and is hugely important for how you experience and perceive things. The limbic system has a direct impact on the autonomic nervous system. If you perceive that you’re in a calm situation, your limbic system will impact the rest of your brain, and thus the rest of your body, to make your body act as if it is in a calm situation. The hypothalamus is also part of the limbic system and plays a role in your body maintaining chemical balances. It is also a reason why you feel physically ill.

To give a little bit more detail on a few things: The sympathetic portion of the autonomic nervous system is the the part of your body that makes your heart beat faster, makes you breathe faster, makes your pupils dilate, makes you sweat, and makes you stop digesting food (your blood is diverted to your muscles so you can run if needed). It is the fight of flight response in your body and has a cascade effect on the rest of your body. If your limbic system is going crazy with emotional trauma, it’ll make your sympathetic nervous system ramp up as well. If you just ate and your body all of the sudden stops digesting food, you may throw up.

The limbic system (emotion and memory area of the brain) also directly impacts almost every other part of your brain. The limbic system is smack dab in the center of your brain, thus connects to everything. This is why being in a really intense situation can change how you feel physically and how you even perceive (time slowing down) a situation. One of the important parts of the limbic system is the hypothalamus.

The hypothalamus plays a huge role in maintaining your body’s “natural state”. If you need food, your hypothalamus is the part that makes you feel hungry. The hypothalamus is part of the limbic system, so it is under these same controls of emotion. Under a really stressful situation, your hypothalamus will react with the release of cortisol, which will affect your blood sugar and can make you feel sick.

Now, all of this kind of paints the limbic system as the bad guy, but that’s not really true. The limbic system is also what integrates emotion into what we experience when something is positive. It’s why your mom’s cooking tastes better if you have fond memories of her. It’s what makes your heart flutter when you’re in love. It’s what makes you remember things. It is even the reason why a truck horn can go off in the dead of night and you won’t wake up, but when someone whispers your name you will.

Why is it that the liver can (to an extent) regenerate but other vital internal organs cannot?

The liver itself is made of individual hexagonal units called hepatic lobules made of liver cells (hepatocytes), blood vessels, and connective tissue that all together perform all the functions of the liver. Think of them like honeycomb cells in a bee hive or individual solar cells in a solar panel.

Cutting off a portion of the liver reduces the total number of lobules, reducing the overall function of the liver. The liver cells can replicate to create more lobules in order to regenerate liver function. However, this is not true regeneration as the form of the regenerated liver (shape) is not the same as the original liver.

The other internal organs are not made of individual units or cannot survive being punctured. Organs like the heart are uniquely shaped and designed for its function. Removal of any part would completely ruin its function. Organs that are made of individual units like the lungs (small air sacks surrounded by vessels) or kidneys (filtering units surrounded by vessels and fluid ducts) cannot be punctured. You cannot breathe properly if there is a hole in your lung and punctures could result in fluid filling the rest of your lungs. Any removal of lung has to be completely sealed, which prevents it from regenerating. Similarly, because of the large blood flow to the kidneys, injury to the kidneys could easily be fatal. Cutting off a part of the kidney means it is not sealed from leaking.

Why does alcohol leave a smell on our breath?

The smell lingers as long as you’re drunk because it’s not coming from residual booze in your saliva, it’s the smell of your blood itself.

When you imbibe an alcoholic beverage, ethanol (the active ingredient that gets you drunk), is absorbed into your bloodstream. Ethanol is a volatile chemical (it evaporates easily), so when alcoholic blood passes through your lungs, some of the ethanol evaporates into the air that you exhale. It’s this process that allows a breathalyzer to measure BAC based on your exhalation.

What is seizure and what causes it?

A seizure occurs when there is out-of-control electrical activity in your brain. A seizure can take many forms, ranging anywhere from an involuntary muscle twitch, to “blanking out,” to losing consciousness and convulsing on ground uncontrollably (which most people think of when they hear the word “seizure”). Seizures can take many forms because they have many causes. They can be focal (i.e. propagating from one area of the brain, such as with a brain tumor or a brain bleed), or can be global (seizure activity everywhere in the brain at once, such as with metabolic disturbances).

If you suspect somebody has a seizure, the first diagnostic test to get is an EEG (electroencephalogram), which is essentially an EKG for the brain. It graphs the electrical activity of the brain. A trained neurologist can interpret normal brain wave activity and differentiate it from possible seizure activity. If you are certain that there is seizure activity, you get an MRI to look for any structural abnormalities that can cause seizures (trauma, tumors, AV malformations, etc).

Seizures are treated in many different ways. Ideally, you treat the underlying cause (get rid of the tumor, correct the metabolic abnormality, etc), but sometimes this isn’t possible. You can also treat them with medications called anti-epileptic drugs. There are many AED’s, with different mechanisms of action and different side effects (agitation, suicidal ideations, dizziness, risk of taking when pregnant). Choosing the right AED can be tricky, because you have to know what type of seizure you’re treating, and weigh the risk of side effects with the benefit of hopefully stopping the seizures.

Identifying triggers and avoiding them is a must (avoiding sleep deprivation, bright/flashing lights, etc). Ketogenic diets have also been found to be beneficial in reducing seizure activity in some patients. Also, patients with epilepsy must know how to avoid certain activities in case they have a seizure while doing them (driving, climbing ladders, cooking with gas, stepping into bath tubs).

If you see somebody that you suspect is actively seizing, the best thing to do is give them room, keep others back, and call 911. Do NOT try and hold them down, and do NOT stick anything in their mouth. It is a common misconception that people with seizures will swallow their tongue. This is physically impossible.

Epilepsy is a very common neurologic disorder. Fortunately, we live in a time where we have so many different ways to treat seizures. New medicines are being invented all the time. Vimpat, for example, was just approved by the FDA 8 years ago, and is now used in hospitals all around the United States. We still have a long ways to go, but we’re making great progress in treating epilepsy.

Why do athletes take ice baths?

The benefits of ice baths have become more ambiguous since first introduced. At its primary level, it’s pretty self-evident. Cold things will help reduce swelling and possibly inflammation. It desensitizes us to a certain feeling of pain and soreness from repetitive or intense exercise.

However, for athletes looking to increase adaptation/strength, inflammation is actually helpful for muscle repair. In a study conducted where people did a 3 month strength training course, the participants that used an ice bath (over gradual cool down) for repair noted reduced swelling and overall soreness but also made smaller gain in muscle mass.

Overall, for athletes at their prime, ice baths may be useful for quick recovery between events (i.e. back to back games) but probably not if they want to get stronger long term.

What is Multiple Sclerosis, also known as MS?

Around the nerves in the brain, there is a covering called myelin. This substance acts as a sheath in the same way wires have sheaths. It helps to keep each ‘wire’ isolated so signals don’t get crossed.

With MS, for some reason, the body’s immune system sees the myelin sheath as a foreign entity, so the immune system starts attacking it just as they would with a virus or bacteria.

The “sclerosis” portion of the MS name deals with scarring. Over time, as the mylein sheath surrounding the nerves is attacked and healed over time, over and over again, scarring in the sheath starts to form which can end up getting so thick that it slows or completely blocks signals trying to go through that particular nerve. Many people with MS over time end up losing the ability to feel certain parts of their body, or lose control of those parts of their body entirely.

There is no known cure, and scientists aren’t completely sure what causes it to begin with. There are of course medications available for people suffering from MS, but the focus is more on slowing the progression of the disease, not stopping it.