You take a sip of water but suddenly burst into uncontrollable coughing — your drink has"gone down the wrong pipe." It turns out that this familiar, protective response is instigated by rare, tiny cells in your airways, scientists discovered in a new study in mice.
These reflexes help expel any inhaled fluid from the airways as soon as possible, to protect the delicate tissues in the lungs that allow us to breathe. If these protective mechanisms fail, bacteria within inhaled fluid can potentially trigger infection and inflammation in the lungs, known as pneumonia. Acid reflux triggers a similar set of reflexes when the contents of the stomach inadvertently travel back up the esophagus.
By submitting your information you agree to the Terms & Conditions and Privacy Policy and are aged 16 or over.These neuroendocrine cells were already known to be in the upper airways, because in rare cases, the cells can give rise to tumors in the voice box.
They found that the neuroendocrine cells from the voice box and windpipe responded to water and acid, whereas the cells from the lungs responded to pressure, as has been shown in previous studies. When activated, these cells release ATP that, at least in mouse tissue in lab dishes, switches on sensory neurons that initiate swallowing and coughing reflexes.