Atemmechanismus

Atemmechanismus refers to the physiological process by which an organism takes in oxygen and expels carbon dioxide. This fundamental process is essential for life, as it provides the body with the oxygen required for cellular respiration and removes the waste product of carbon dioxide. In humans and many other mammals, the primary muscles involved in the breathing mechanism are the diaphragm and the intercostal muscles.

Inhalation, or breathing in, is an active process. When the diaphragm contracts, it flattens and moves downward, increasing the volume of the thoracic cavity. Simultaneously, the external intercostal muscles contract, pulling the rib cage upward and outward, further expanding the chest. This increase in volume leads to a decrease in pressure within the lungs compared to the atmospheric pressure, causing air to rush into the lungs.

Exhalation, or breathing out, is typically a passive process during quiet breathing. When the diaphragm and external intercostal muscles relax, the diaphragm moves upward and the rib cage moves downward and inward due to the elastic recoil of the lungs and chest wall. This decreases the volume of the thoracic cavity, increasing the pressure within the lungs above atmospheric pressure, forcing air out. Forced exhalation, such as during strenuous activity or coughing, involves the contraction of internal intercostal muscles and abdominal muscles to forcefully expel air.

The regulation of the breathing mechanism is primarily controlled by the respiratory centers in the brainstem, specifically the medulla oblongata and the pons. These centers respond to changes in blood oxygen and carbon dioxide levels, as well as pH, to adjust the rate and depth of breathing to meet the body's metabolic needs.