Subtitles section Play video Print subtitles It's AumSum Time. Can you guess the title of my next video? Hurry up. Write your guess in the comments section below. How does anesthesia work? It acts like a sponge and absorbs all the pain. No. Now a days, during a surgery or a dental treatment, we don't feel pain. Sometimes, we are not even conscious. This state is called anesthesia and the drugs which induce anesthesia are called anesthetics. There are three types of anesthesia, local, regional and general. Local and regional anesthesia are almost the same. In these types, the anesthetics block the nerves of only a small area of the body. Without making the person unconscious. Hence, the pain signals from that area don't reach the brain, making it insensitive towards pain. Now, in general anesthesia, the anesthetic is injected through a vein, making us completely unconscious. It is thought that the general anesthetic interrupts the normal firing pattern of neurons in the brain. Hence, different regions of the brain cannot communicate effectively with each other. Making us completely unconscious. Topic: Chapped lips. What causes chapped lips? Making weird faces. Oh no. Our lips are very sensitive. This is because the outermost layer of our skin called stratum corneum is much thinner on our lips than on any other body parts. As it is thinner, the blood vessels inside them are more prominent. Making our lips appear reddish or pinkish. Besides this, the skin on our lips doesn't have oil and sweat glands which secrete substances to moisturize the lips. Hence, our lips have very less moisture. Now, usually during cold months, as the air has less moisture, the moisture from our lips evaporates. Causing them to get dry and chapped. So to provide moisture, we can lick our lips and apply saliva. No. Saliva draws more moisture and heat from our lips and evaporates, thus leaving our lips more drier than before. Thus, making the condition worse. What is déjà vu? It is a magical power. No. Déjà vu is a French term which literally means 'already seen'. As the name suggests, it is a strange feeling that the current situation has happened before. It is an experience in which places seem familiar, although you have visited that place for the first time. But what causes déjà vu? One of the prevailing theories suggests that sometimes. Visual information from one of our eyes is transmitted a little late to the brain. So, information from first eye reaches the brain first. Now, when the information from the other eye reaches the brain a little late. Our brain receives the same information twice. Hence, the situation or place appears familiar. It appears as if we have seen it already, i.e., we experience déjà vu. Why do we bite our nails? To save our expenses on manicure. No. Nail biting or onychophagia is a bad habit and there is no specific reason why people do it. Ha, I'll find the reason in only 2 seconds. Don't bother. A habit forms due to three things, a trigger, action and reward. So, in case of nail biting, a research suggests that a broken nail which is hurting can be a trigger. Biting and removing it is the action. When the broken nail is taken off, the pain is reduced and we feel better. This is our reward. Now, if we again encounter similar triggers like a broken nail. We repeat the same action to get the reward which gradually causes onychophagia. i.e., we get a habit of nail biting. Topic: Heat transfer. Why are cloudy nights warmer than clear nights? Hey. Look at the weather outside. It is too cloudy. No. Don't go near that bonfire. It is going to be warm tonight. You don't want to listen to me, right? Alright. Go ahead. Look. I told you. At least now will you listen to me. During the day, our earth receives light from the sun and gets heated. Now, during a clear night, i.e., when there are no clouds, this heat easily escapes through the atmosphere into space. Resulting in cooling of the earth. Now, to understand what happens on a cloudy night, let us heat the earth once again. In this case, the clouds act like a blanket, preventing the heat from escaping into space. Since the heat remains in the atmosphere, cloudy nights are warmer than clear nights.