Why Do We Feel Thirsty?
We feel thirsty many times a day. But can we imagine what it would be like to be thirsty for so many days? If a person does not get anything to quench his thirst for several days, he will die.
Thirst is the only source of fluid loss. Is a change in the amount of salt in the blood a cause of thirst? Our blood contains a certain amount of salt and water. When the amount of salt in it exceeds that of water, we feel thirsty.
There is a part of the human brain called the center of thirst. It reacts to a decrease in the amount of salt in the blood. When this amount changes, this part of the brain sends a message to the back of the throat, from where the message is sent back to the brain. Messaging makes us feel thirsty.
Peeling an onion releases an inflammatory substance. It is a type of oil rich in sulfur which causes a pungent odor and inflammation in the eyes. The eyes blink repeatedly and produce tears in response. This is how this substance washes our eyes.