Topic: Breathing.
Why do we get hiccups?
We get them when our friends think of us.
No.
We get hiccups mainly because of our diaphragm.
Diaphragm is a dome shaped muscle between our lungs and stomach.
It generally works perfectly.
Just like me, right?
No.
When we inhale, our diaphragm contracts helping us take in air into the lungs.
When we exhale, it relaxes, helping us give out air.
However, sometimes this contraction does not happen properly.
One of the reasons is excess eating.
Eating too much too quickly causes our stomach to swell, causing discomfort to our diaphragm.
Due to this, our diaphragm contracts irregularly in a jerky way, making us suck air suddenly.
This air rushes through our voice box, making the vocal cords to close suddenly, creating a hiccup.
Topic: Pathogens.
Why do we get fever?
So that we can take a holiday from work.
No.
Fever is a protective response of our body to fight against pathogens such as bacteria, viruses and fungi.
These pathogens cause diseases.
Hence, when pathogens enter our body, the immune cells such as white blood cells produce chemicals called pyrogens which are released in to the bloodstream.
I thought like movies, they are released in theatres.
Please, pay attention.
Hypothalamus, which is a small part of our brain, regulates our body temperature.
However, when these pyrogens reach the hypothalamus, it starts to raise our body temperature, thus producing fever.
Now, one of the reasons for producing this fever is that many pathogens cannot survive at high temperatures.
Thus, they die and we remain safe.
Topic: Pimples.
Why do we get pimples?
Because they don't want me to look handsome.
No.
Pimples are caused due to the activity of sebaceous gland present inside our skin.
This gland produces an oily substance called sebum.
Sebum comes up to the skin surface through a pore and moisturizes our hair and skin.
Like a moisturizer.
Absolutely.
However, sometimes the pore gets blocked due to dead skin cells.
Due to this blockage, the sebum gets accumulated, creating a bump.
As sebum is a very good source of nutrients for the bacteria in our skin, they start to grow in that area, leading to an infection.
Our immune system responds to this infection by sending blood and immune cells.
Blood makes the area red whereas the immune cells kill the bacteria, resulting in inflammation and formation of a pimple.
Topic: Thermoregulation.
Why do dogs pant?
Because they want to tease us.
No.
They pant for thermoregulation.
Thermoregulation is the process by which organisms maintain their internal body temperature.
Well.
I use an air conditioner.
You're unbelievable.
When we humans feel hot, the sweat glands which are present all over our body produce sweat.
Sweat is about 99% water.
This water takes our body heat and evaporates, helping us to lose heat.
Now, dogs also have sweat glands.
However, they are present under their paws.
But as their paws are small and are mostly used to stand and sit, sweating through them to lose heat is not enough.
Hence, dogs pant.
During panting, they take their long tongue out and breathe heavily.
Due to this, the water in their saliva evaporates taking their body heat, thus helping in thermoregulation.
Topic: Taste Buds.
Why mint tastes cold?
Maybe because it is manufactured in Antarctica.
Not at all.
Wait, I will explain.
Our tongue is actually a muscle which consists of many taste buds or receptors.
Are they similar to my earbuds?
No.
When foods having flavors such as sweet, salty, sour, bitter or umami come in contact with these taste receptors and activate them,
They send signals to the brain, telling us their taste.
However, when we eat mint, it feels or tastes cold.
This is because mint contains a compound called menthol.
Menthol does not activate the taste receptors, but instead, it activates the cold sensing receptors in our tongue.
Hence, these receptors send messages to our brain signaling cold.
As a result, the brain thinks that something cold is present in our mouth, thus making mint taste cold.
Topic: Snoring.
Why do we snore?
I don't snore, I sing.
Alright.
Now let me explain.
Snoring is a noisy rattling sound occurring during sleep.
Oh really, I thought snoring is a pleasing piano sound.
Please listen.
Snoring is basically caused due to obstruction of air in our respiratory tract during breathing.
When we breathe, we take in air through nose or mouth which then passes down the throat into the lungs.
Normally, when we aren't asleep, our mouth parts like soft palate and uvula keep this tract wide open, allowing air to pass easily.
However, excess growth of soft palate and uvula in some people causes snoring.
So when these people sleep, these parts fall on the back of their throat, creating an obstruction.
Hence, when they inhale, the air hits these parts making them vibrate, which we hear as snoring.
Topic: Freckles.
Why do we get freckles?
Because they are being sold for free.
No.
We get freckles because of melanin.
Melanin is a pigment produced by cells called melanocytes in our skin.
It gives color to our hair and skin.
Will it give color to my door.
Please listen.
Besides giving color, melanin also acts as a natural defense against the sun's harmful ultraviolet radiation.
When we are in the hot sun, our skin which is exposed to the sunlight activates its melanocytes, causing them to produce melanin.
Melanin absorbs the ultraviolet radiation, thus protecting us and in due course, darkening the skin.
However, in some people, this melanin is not produced evenly.
This means some parts of their skin produce more melanin as compared to other, thus creating small dark patches on their skin called freckles.
Topic: Myopia.
What causes nearsightedness?
Excess staring at junk food.
No.
When light from an object enters our eyes, our eye lens bends it such that the image is formed on the retina.
However in some people, this image is formed before the retina.
Such defect is called nearsightedness or myopia.
A person with myopia cannot see distant objects clearly.
But why?
Wait, I will explain.
To focus image of a distant object on the retina, our eye lens becomes thin.
However, in people with myopia, the lens cannot become adequately thin, thus forming image before the retina and making it difficult to see.
Moreover, when the eyeball is elongated more than normal, the distance between the lens and the retina increases resulting in the formation of image before the retina
Thus causing difficulty in seeing the distant object.
Topic: Red eye effect.
Why do my eyes glow red in photos?
Because there is a devil hidden in you.
Stop bluffing.
Alright.
I will explain.
It happens because of blood vessels in our eyes and pupil.
Pupil is a small opening whose size is adjusted by the circular muscle called iris.
In bright light, the iris contracts making the pupil smaller, thus allowing less light to enter into our eyes.
In dark, the iris relaxes making the pupil larger, thus allowing more light to enter and also exposing the blood vessels in our eyes.
Hence, when we take a photo in such a dark environment, the flash of light from the camera floods into our eyes at once.
Some of this light gets reflected from the blood vessels onto the camera before our iris can contract, making our eyes glow red in photos.
Topic: Human Nose.
Why does spicy food make your nose run?
Because it is not that strong to make me run.
No.
Our nose consists of tiny hair and a sticky substance called mucus.
Can I use this mucus to stick my broken vase?
Gross.
Please don't do that and listen.
During breathing, the hair and mucus trap harmful substances, thus prohibiting them from entering deep inside the body.
Now, spicy food items like chili, mustard, horseradish and wasabi contain chemicals called capsaicin and allyl isothiocyanate.
When we eat such food items, the capsaicin and allyl isothiocyanate travel through the pharynx and reach our nose.
Here, the chemicals activate the heat sensing receptors, thus causing inflammation in our nose and irritation of the mucus.
Hence, as a defense mechanism more mucus is produced in our nose to get rid of these chemicals, thus making our nose run.