Your nose isn't the only thing that senses cigarette smoke -- researchers have found that odor receptors exist in your lungs, too.
The odor receptors in the lungs are called pulmonary neuroendocrine cells, and were discovered by researchers from Washington University in St. Louis, the Washington University School of Medicine and the University of Iowa Carver College of Medicine.
These cells are in the membranes of the neuroendocrine cells of the lungs. That means that when the lungs detect the smell of cigarette smoke, it prompts hormones to be released that then lead to constriction of the airways.
Researchers noted that these particular cells could help explain why people with respiratory diseases are so sensitive to things like perfumes and traffic fumes.
The findings were published earlier last year in the American Journal of Respiratory Cell and Molecular Biology, but were publicized only recently.
Last year, a study presented at a meeting of the American Chemical Society showed that odor sensors exist also in the blood and heart, as well as the lungs, LiveScience reported.