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Three‐Dimensional Structure of the Nasal Passageway of a Hagfish and its Implications for Olfaction
Author(s) -
Holmes William M.,
Cotton Ross,
Xuan Viet Bui,
Rygg Alex D.,
Craven Brent A.,
Abel Richard L.,
Slack Robert,
Cox Jonathan P.L.
Publication year - 2011
Publication title -
the anatomical record: advances in integrative anatomy and evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.678
H-Index - 62
eISSN - 1932-8494
pISSN - 1932-8486
DOI - 10.1002/ar.21382
Subject(s) - anatomy , olfaction , olfactory epithelium , hagfish , vomeronasal organ , olfactory system , biology , neuroscience , vertebrate , biochemistry , gene
From high‐resolution (65 μm) data acquired by magnetic resonance imaging, we have reconstructed the nasal passageway of a single adult hagfish specimen (probably Eptatretus stoutii ). We have used this reconstruction to investigate how the anatomy and morphometry of the nasal passageway influence the olfactory ability of the hagfish. We found that the long, broad section of the passageway preceding the nasal chamber will delay the response to an odor by 1–2 s. Diffusion of odorant to the olfactory epithelium, on which the olfactory sensitivity of an animal depends, will be favored by the relatively large surface area of the olfactory epithelium (∼140 mm 2 ) and a modest expansion in the nasal chamber. Oscillating flow (0.3–0.4 Hz) within the narrow (65–130 μm) sensory channels of the nasal chamber is laminar (Reynolds number ∼ 5) and quasi‐steady (Womersley number generally less than one). Distribution of flow over the olfactory epithelium may be aided by: (a) a narrowing before the nasal chamber; (b) partial blockage of the nasal passageway by a protrusion on the central olfactory lamella; and (c) the inward inclination of the olfactory lamellae. Anat Rec,, 2011. © 2011 Wiley‐Liss, Inc.