Big head son's new exploration has begun-
Everyone should know that pain is a physical feeling. To understand this problem, we must start with the receptors of the body.
All parts of the body are covered with various receptors, which can "detect" the "news" of changes in the internal and external environment of the body and transmit these "news" to the brain, thus forming feelings such as pain and itching.
There are two types of receptors:
Endoreceptors, distributed in muscles, joints and viscera, mainly feel the changes inside the body.
External receptors, such as eyes, ears, nose, tongue and skin, mainly feel the changes of the external environment, which we also call sensory organs (sensory organs for short).
There are many kinds of sensory nerve endings in the skin, which can be divided into several types according to their physiological characteristics, and they feel cold, heat, touch pressure, pain and other stimuli respectively.
When the human body is stimulated by chemicals, heat or shock, which will damage the body tissue, pain receptors will transform the stimulation into nerve impulses and quickly transmit them to the brain, resulting in painful feelings and reactions.
Hair is mainly composed of an extremely hard protein called keratin, which can even be regarded as a special derivative of skin, without nerves and blood vessels. When they are pushed from the bottom up, they actually start to harden and lose their vitality, which is called "keratinization".
Therefore, it won't hurt when you cut your hair.
(Some pictures are from the Internet)