In the oxidation by oxygen of organic substances. The relationship of the digestive and respiratory systems is the oxidation of organic substances by oxygen (3).
Organic matter is absorbed in the digestive system and enters the cells; in the respiratory system, oxygen is absorbed and also enters the cell, and then in the process of energy metabolism, organic substances are oxidized.
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.