摘要
Breathing is considered the common factor that links studying,sleeping,and activities.It is one of the primary indicators that is frequently considered when determining whether or not an unconscious individual is still alive.The evolution and development process of the respiratory system that occurs in a foetus is primarily from head to tail(cephalocaudal).Many changes occur throughout this period until the 28th week of pregnancy at which the foetus^respiratory system will attain adequate development for the rest of his or her life.The respiratory system comprises of the lungs and the encompassing thoracic wall,which includes the thoracic cages,midriff(diaphragm),and the abdominal wall.Spirometry is a procedure used for estimating air volumes that enter and exit the pulmonary system with the aid of a spirometer.The various pulmonary parameters that reflect pulmonary ventilation are of great significance in diagnosing respiratory diseases.The respiratory system will be discussed in more detail in this article.