1) blood vessels narrow, disrupting blood supply;
2) some of the hemoglobin molecules combine with carbon monoxide, forming a strong connection, so hemoglobin is not able to transport oxygen and carbon dioxide;
3) in smokers, harmful substances from tobacco smoke are deposited on the walls of blood vessels, which increase the fragility of blood vessels, increase blood clotting, which leads to cardiovascular diseases.
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.