Respiratory system

The respiratory system (systema respiratorium), or respiratory apparatus (apparatus respiratorius), supplies the body with oxygen and removes carbon dioxide from it. This system consists of the respiratory tract and paired respiratory organs - the lungs. In accordance with the location of the respiratory tract are divided into upper and lower divisions. The upper respiratory tract includes the nasal cavity, nasal and oral parts of the pharynx. The lower respiratory tract includes the larynx, trachea, bronchi (bronchial tree). Respiratory tracts are tubes of different size and shape, the lumen of which is preserved due to the presence in their walls of the bone or cartilaginous skeleton. From the inside, from the side of the lumen, the walls of the respiratory tract are lined with a mucous membrane, which is covered with a ciliated epithelium. In the mucosa, there are many glands secreting mucus, and blood vessels. Due to this, the airways perform not only air-conducting, but also protective function. In them, the air is cleared of foreign particles, moistened, warmed.

In the lungs, gas exchange takes place. From the alveoli of the lungs through diffusion into the blood of the pulmonary capillaries oxygen enters, and back - from the blood into the alveoli leaves carbon dioxide.

The respiratory system includes a complex organ, the larynx, which performs not only an air-conducting, but also a voice-forming function.