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Breathing is an involuntary function of the central nervous system (CNS). The breathing pattern is adjusted around other activities (such as speech and eating), and breathing rates change to match the metabolic demands of the body. How is this accomplished?
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The breathing pattern of inhalation followed by exhalation is controlled by a neural circuit in the brainstem.
Breathing is regulated by feedback mechanisms involving CO2 sensitive cells in the brain and O2 sensitive cells in the great arteries.
Brain chemosensitive cells sense CO2 levels through changes in hydrogen ion concentration, whereas nodes in the aorta and the carotid arteries are sensitive to blood O2 levels.
The basic breathing rhythm is an involuntary function that is modified by feedback information that conveys the body’s need for an adequate O2 supply and CO2 elimination.