Swipe the back of your hand with a fingernail to explain why the white stripe turns red and then disappears without leaving a trace

When pressed, small vessels (mainly capillaries) are pressed, the blood flow in them stops, the skin color is pale, after the pressure stops, the blood flow is restored, but due to short-term ischemia (lack of blood flow), there is a compensatory increase in blood flow, so to speak, short-term excessive increase in blood flow to restore tissue nutrition – the color turns pink (blood rushed to this place a little more than usual), and after a while, the blood flow returns to normal, compensatory increase in blood flow compensates for ischemia and returns to normal – to normal blood flow – the color becomes normal .

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.