Sisäänhengittäminen

Sisäänhengittäminen, in Finnish, refers to the act of inhaling or breathing in. It is a fundamental biological process that is essential for life. During inhalation, the diaphragm and intercostal muscles contract, increasing the volume of the thoracic cavity. This volume increase leads to a decrease in pressure within the lungs, causing air to flow from the higher pressure outside the body into the lungs.

The inhaled air, which is rich in oxygen, travels through the trachea, bronchi, and into the alveoli, tiny air sacs in the lungs. Here, oxygen diffuses across the thin walls of the alveoli and capillaries into the bloodstream. Simultaneously, carbon dioxide, a waste product of cellular metabolism, diffuses from the blood into the alveoli to be expelled from the body during exhalation.

The rate and depth of inhalation are regulated by the respiratory center in the brainstem, which responds to changes in blood carbon dioxide and oxygen levels, as well as other stimuli. Conscious control over breathing is also possible to a certain extent, allowing for activities like holding one's breath or speaking.

Inhalation is the first half of the respiratory cycle, preceding exhalation. Together, these two processes ensure the continuous exchange of gases necessary for the body's metabolic functions and overall survival. Any disruption to this process can have serious health consequences.