Researchers at UCLA collaborated with Stanford University and concluded that sighing is a reflex. On average, each individual sighs about every five minutes. Sighing inflates alveoli, sacs within the lungs that allow oxygen and carbon dioxide to enter or leave the bloodstream, and prevents alveoli from collapsing. Researchers were able to identify the protein in the brain that regulates the sighing reflex. This knowledge provides a gateway to potential cures for human breathing disorders.
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