Domestic cat noses function just like high-tech chemical analyzers

Are cat noses now competing with dog noses?

"... A computer simulation suggests that the nasal structures involved in their sense of smell work like parallel coiled gas chromatographs -- highly sensitive lab gear used for the analysis of the chemical makeup of substances.

Until now, the intricate mechanism by which mammalian noses detect odors has remained elusive. While previous studies hinted at the similarity between the nose and a gas chromatography device in terms of odor detection through inhaled air, the specific parallels were not clear.

According to the research team, the evolutionary change in cats' nasal structure, driven by their small heads, has resulted in a labyrinthine airway system that not only fits but also enables cats to adapt to diverse environments. ...
kthrough was achieved through micro-CT scans of a cat's skull, allowing for the identification of tissue types in the feline nasal cavities. ...
“The cat nose probably has a similar complexity level as the dog’s, and it’s more complex than a rodent’s ...

team observed two distinct zones of airflow. The first zone comprised respiratory air that underwent filtration and gradually dispersed over the palate before reaching the lungs. The second zone, however, traveled through a central passage and reached the olfactory region at the rear of the nasal cavity.

The simulation revealed another intriguing finding: the air directed towards the olfactory region is subsequently recirculated through parallel channels upon arrival."

From the abstract:

"The peripheral structures of mammalian sensory organs often serve to support their functionality, such as alignment of hair cells to the mechanical properties of the inner ear. Here, we examined the structure-function relationship for mammalian olfaction by creating an anatomically accurate computational nasal model for the domestic cat (Felis catus) based on high resolution microCT and sequential histological sections. Our results showed a distinct separation of respiratory and olfactory flow regimes, featuring a high-speed dorsal medial stream that increases odor delivery speed and efficiency to the ethmoid olfactory region without compromising the filtration and conditioning purpose of the nose. These results corroborated previous findings in other mammalian species, which implicates a common theme to deal with the physical size limitation of the head that confines the nasal airway from increasing in length infinitely as a straight tube. We thus hypothesized that these ethmoid olfactory channels function as parallel coiled chromatograph channels, and further showed that the theoretical plate number, a widely-used indicator of gas chromatograph efficiency, is more than 100 times higher in the cat nose than an “amphibian-like” straight channel fitting the similar skull space, at restful breathing state. The parallel feature also reduces airflow speed within each coil, which is critical to achieve the high plate number, while feeding collectively from the high-speed dorsal medial stream so that total odor sampling speed is not sacrificed. The occurrence of ethmoid turbinates is an important step in the evolution of mammalian species that correlates to their expansive olfactory function and brain development. Our findings reveal novel mechanisms on how such structure may facilitate better olfactory performance, furthering our understanding of the successful adaptation of mammalian species, including F. catus, a popular pet, to diverse environments."

Cat noses function just like high-tech chemical analyzers Researchers create 3D computer model of cats nose

Domestic cat nose functions as a highly efficient coiled parallel gas chromatograph (open access)

Fig 1.

CT scans showing nasal cavity cross sections of a) human, b) rat, and c) domestic cat. The dark spaces on the scans are the nasal airways. As odorous air is drawn into the nose, it flows through these labyrinthine structures.