The air passage respiratory organs include the nasal cavities, throat (pharynx), larynx (larynx) and windpipe (trachea). The exchange of gases between the air and the blood occurs directly in the lungs (pulmo), into which a part of the air passages, the bronchial tubes protrude. The air passages clean, moisten and warm the inhaled air to prepare it for the lungs.
Respiration is an involuntary procedure. It is controlled by the respiratory center, which is located in the elongated bone marrow. Inhaling (inspiration) alternates automatically with exhaling (Expiration).
During inhaling, the respiratory muscles, which are composed of the intercostal muscles (intercostal muscles) and the diaphragm (diaphragma), contract. This raises the costal arch and thus enlarges the chest (thorax). During exhaling, the ribs are lowered again and the diaphragm relaxes so that the chest is smaller again. Under normal conditions, an adult breathes 12 to 17 times a minute, a child 20 to 25 times.
All of the body's cells require oxygen to function, since the vital function of cellular generation of energy depends on this element. During inhalation, oxygen is supplied to the body. The metabolite of oxygen, carbon dioxide, is eliminated during exhalation. The respiratory organs perform the breathing function. These organs include the nose, the throat (pharynx), the larynx, the windpipe (trachea), the bronchi and their branches in the lungs (pulmo).
The air inhaled through the respiratory organs contains about one-fifth oxygen and nearly four-fifths nitrogen plus smaller amounts of carbon dioxide and inert gases. Only one-fifth of the inhaled oxygen is utilized. The gas exchange process takes place in the pulmonary air cells (alveoli).
The respiratory combustion (oxidation) process produces carbon dioxide (C02), water vapor, heat and above all free energy, which can be used for chemical work and muscle work. The resulting heat maintains a relatively constant body temperature in humans between about 97.5 and 98.6°F (36.5 and 37.0°C).
During exertion, the human metabolic rate increases, so that oxygen consumption increases as well. In older persons, metabolism generally slows down, reducing the oxygen consumption rate as well.
The Human 3D software features diagrams of the human respiratory system.
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