Inhalation, or breathing in, is accomplished through a coordinated effort involving the diaphragm and rib muscles, creating a pressure difference that draws air into the lungs.
Here's a breakdown of the process:
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Diaphragm Contraction: The diaphragm, a dome-shaped muscle at the base of the chest cavity, contracts and moves downward. This increases the vertical space within the chest.
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Rib Muscle Action: The muscles between the ribs (intercostal muscles) also contract, pulling the rib cage upwards and outwards. This expands the chest cavity further in the horizontal plane.
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Increased Chest Cavity Volume: The combined actions of the diaphragm and rib muscles significantly increase the volume of the chest cavity.
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Decreased Pressure: As the chest cavity expands, the pressure inside the lungs (intrapulmonary pressure) decreases, becoming lower than the atmospheric pressure.
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Airflow into Lungs: Because air naturally flows from areas of higher pressure to areas of lower pressure, air rushes into the lungs from the atmosphere until the pressure inside the lungs equalizes with the atmospheric pressure.
In summary, inhalation is an active process driven by muscle contractions that increase the volume of the chest cavity, decreasing the pressure within the lungs and drawing air in.
