Why laboratory thermometer is not used to measure the body temperature?

Normally, we check our body temperature using clincal thermometer. This is because, the laboratory thermometer is different from that of clinical thermometer. A clincal thermometer has a kink present on it. When we check our body temperature, the kink present in it prevents the mercury from falling back down. Thus, helping the thermometer to hold the temperature recorded by it and giving us an accurate reading. Now, in a laboratory thermometer, the kink is generally absent. This is because of the laboratory thermometer is meant to measure the immediate temperature. Hence, after recording our body temperature, until we check it, the mercury will fall. Thus, it doesn't give the accurate reading.

What happens if we drink more sea water?

Normally we do not drink sea water because the salt content present in the sea water can cause serious consequences in our body. Now, normally in our body, the amount of water and salt, inside and outside our cells are same. However, if we drink sea water, the amount of salt outside our cells will increase, making the outside region more concentrated. Hence, to dilute the outside region and maintain balance, inside and outside the cells, the water present inside the cells start flowing outside(diffusion) and causing our cells to shrink. Moreover, to remove the extreme amount of salt, our kidneys will produce more urine. Making us to urinate more water, it causes severe dehydration.

Why is whale vomit so valuable?

Some scientists suggests that the sperm whales eat animals like squids, they digest most of their body parts. However, the sharp beaks of the squids are indigestible. It causes irritation in the whales digestive tract. Hence, the whales digestive tract produces a waxy substance called ambergris. Ambergris covers the sharp beaks, helping them to pass through the digestive tracts quickly. Some people thought that whales vomitted this ambergris. However, a research suggests that the ambergris is expelled from the other end of the whales as excreta. Then overtime, this ambergris reacts with air and salty water etc., And hardens to form a waxy rock. This waxy rock or ambergris is used by the perfume companies. This ambergris helps the perfumes to stick to our skin, making perfume last longer. Hence, perfume companies pay thousands of dollars for just a pound of ambergris.

How do fish breathe under water?

Fish breathe under water using the oxygen that is dissolved in water. To absorb oxygen from water, fish use special type of organs called gills. Gills are full of blood vessels. Also, the walls of the gills and blood vessels are very thin. Now, during breathing, fish take in water through their mouth and forcefully push it through their gills. When the water moves through the gills, the dissolved oxygen from the water passes through the thin walls of gills and blood vessels and enters the blood. Apart from this, the waste carbon-di-oxide in the blood passes into the water. Thus,helping fish to breathe under the water.

Why don't penguins feet freeze?

Penguins live in very cold climates and walk on ice. Hence, their body have developed certain adaptations to avoid losing body heat and to protect their feet from freezing. One of the adaptations is countercurrent heat exchange. At the top of a penguin's feet, the arteries and veins wrap around each other. Now, when the warm blood flows through the arteries to the feet, much of the heat from warm blood gets transferred to the cold blood in veins which is carrying blood away from the feet. In this way, penguins do not lose their heat from the feet to the ground. Also, the blood which reaches the feet is warm enough to keep the feet above freezing point, helping the penguin to not get frostbite.

What is bruxism?

Some people always grind their teeth during daytime and some others during night time. These people grind their teeth unknowingly. The medical term for grinding the teeth is called bruxism. Bruxism can be caused due to stress, medications etc., According to the research, bruxism is common on people who snore. Snore occurs when our tongue, uvula etc., may relax and fall back of our throat, blocking the air pathway and cause difficulty in breathing. Now, bruxism reopens the pathway. Bruxism or grinding of teeth causes movement in the relaxed muscles(tongue). Due to which the muscles return back to their original positions. Thus, opening the air pathway.

Why do our muscle gets sore?

When we begin to gym and perform a new intense physical workout, our muscle begin to sore in the next morning. This soreness is called Delayed Onset Muscle Soreness (DOMS). DOMS usually occurs after eccentric contractions. When the muscle is contracting or lengthening at the same time called eccentric contractions. For example, if we lower our dumbbell, our bicep muscle is slowly relaxing and lengthening. But, at the same time, it is still contracting by holding the heavy weight of the dumbbell. Similarly, in a squat, as we lower ourselves, our quadriceps muscle is lengthening. But at the same time, it is still contracting to hold our upper body weight. Such eccentric contractions generate tension in the muscles, creating minute tears in them. Thus causing the sourness or pain.

What is tardigrade?

A tardigrade is one of the smallest animals. It can grow only about  1mm or less in length. However, it is the toughest animal in the whole world. Scientists say that tardigrades can able to survive in extremely inhospitable conditions. When the environment is inhospitable, the tardigrades enter into a state called cryptobiosis. In cryptobiosis, they curl up into ball like structure called tun.  All their metabolic process are almost stop. In this state, the tardigrades can survive in about -459F and even about +300F. They can live inside the oceans and withstand huge pressure of water. And also, they can even survive on vaccum and space and withstand radiation. Later, when the conditions are stable, they can again come back to their normal form.

Cryptobiosis

Why do we sleep?

There are actually 2 factors that makes us sleep. 
1. Light
2. Adenosine

1.Light:
When we see light in the morning, our body releases more amount of Cortisol which keeps us awake. While when it is dark, our body releases more amount of melatonin which makes us sleep.

2.Adenosine :
Accumulation of adenosine is the second factor that makes us sleep. Adenosine is accumulated in our brain because of stress, work loads during day time. Now, when we sleep, our brain take time reabsorb the accumulated adenosine. So that our brain is ready for the next day.
                Besides this, sleeping helps brain to reorganize information and clear unwanted memories. Moreover, while sleeping we use very less energy. Thus, sleeping also helps us to conserve energy.

Why is glass transparent?

The particle is said to be transparent, if the photons are not absorbed by the substance. And thus, the photons can easily pass through the substance. If the particles absorb photons, they are not transparent. And that particles are said to be opaque (wall). This is due to the presence of gaps between the electrons in the atoms of the particles. If the gap between the two electrons in the orbit of the particles are less, then the photons can be easily absorbed by the electrons. And the object becomes opaque. If the gap between two electrons are more, then the photons may escape, they are not absorbed by the electrons, making the object transparent.

What causes wrinkling?

Our skin consists of two important proteins called collagen and elastin. Collagen keeps our skin firm and tight. Elastin gives our skin flexibility and elasticity. It allows our skin to stretch, wrist and contract. As we age, our skin produces less elastin and collagen causes our wrinkles. Some people got wrinkles at an early age because of over exposure of UV radiation to the skin. Long term exposure of Ultra violet radiation causes collagen and elastin in our skin to break down. Besides this,smoking and poor nutrition are also the major factors.

What is frostbite?

Our core body temperature is 36°C or 98°F. To maintain this temperature, our blood transports warmth all over the body. But, prolonged exposure to cold temperature can decrease our body's core temperature. Hence, in order to maintain the core temperature, our brain constricts the blood vessels of our limbs. It diverts the blood vessels to the vital organs to maintain the core temperature. As our limbs don't get sufficient warmth, they started to freeze, giving us frostbite.

                   Frostbite progresses in 3 stages. 
1. Frostnip - Our surface of the skin freezes. 
2. Superficial frostbite - often ice crystals formed in our skin. 
3. Deep frostbite - The underlying tissues, vessels, bones etc., freezes and permanently damaged.

Why do we not feel pain when we cut our hairs?

Inside our body, there are millions of nerves. These nerves helps us to sense our surroundings and feel pain, touch etc.,Generally, the skin below the hair are made up of dead cells. Hence, the nerves present in it has not be able to send messages to brain. As a result, we don't feel pain while cutting our hairs.

Why do our fingers get wrinkly?

Normally, if we place our hands in water, it would cause wrinkling of hands. This happens because of shrinking or constricting of blood vessels caused due to nervous system. This, in turn, causes the deeper layer of the skin to constrict. Scientists suggests that it may due to evolutionary adaptation. Wrinkly fingers help in a better grip to pick up wet objects, preventing them falling from our hands. Even our feet gets wrinkly, helps to walk in water without slipping.