sisäänhengittämisestä

Sisäänhengittäminen, often referred to as inhalation or inspiration, is the process of taking air into the lungs. It is the first phase of the breathing cycle, which also includes exhalation. This vital physiological function allows the body to obtain the oxygen necessary for cellular respiration and to expel carbon dioxide, a waste product of metabolism.

The mechanics of inhalation involve the diaphragm, a dome-shaped muscle located at the base of the chest cavity, contracting and flattening. Simultaneously, the external intercostal muscles between the ribs contract, pulling the rib cage upwards and outwards. These actions increase the volume of the thoracic cavity, which in turn decreases the pressure within the lungs relative to the atmospheric pressure outside the body. This pressure gradient drives air to flow into the lungs.

In normal, quiet breathing, inhalation is an active process driven by muscle contraction. However, during exertion or respiratory distress, accessory muscles in the neck and abdomen may also assist in the process, making inhalation a more forceful act. The amount of air inhaled can vary significantly depending on factors such as physical activity level and lung capacity. The regulation of breathing, including the depth and rate of inhalation, is primarily controlled by the respiratory center in the brainstem, which responds to signals related to blood oxygen and carbon dioxide levels.