vdechování

Vdechování is the Czech word for inhalation, the process of breathing in. It is a fundamental physiological action essential for life, involving the intake of air into the lungs. This process is part of the larger respiratory cycle, which also includes exhalation, the expulsion of air.

During inhalation, the diaphragm, a large dome-shaped muscle located at the base of the chest cavity, contracts and moves downward. Simultaneously, the external intercostal muscles between the ribs contract, lifting the rib cage upward and outward. These actions increase the volume of the thoracic cavity, creating a lower pressure inside the lungs compared to the atmospheric pressure. Consequently, air flows into the lungs down this pressure gradient.

The air entering the lungs is a mixture of gases, primarily nitrogen and oxygen, along with smaller amounts of carbon dioxide, argon, and other trace gases. As the air travels through the respiratory passages (nasal cavity, pharynx, larynx, trachea, bronchi, and bronchioles), it is warmed, humidified, and filtered. In the alveoli, the tiny air sacs at the end of the bronchioles, gas exchange occurs. Oxygen from the inhaled air diffuses across the thin alveolar walls into the bloodstream, while carbon dioxide from the blood diffuses into the alveoli to be exhaled.

Inhalation can be voluntary or involuntary. Involuntary breathing is controlled by the respiratory centers in the brainstem, which regulate the rate and depth of breathing based on the body's needs for oxygen and the removal of carbon dioxide. Voluntary control allows for conscious modifications to breathing patterns, such as holding one's breath or taking deep breaths.