Document Detail

Surface area-volume relationships for the mastoid air cell system and tympanum in adult humans: Implications for mastoid function.
MedLine Citation:
PMID:  20450279     Owner:  NLM     Status:  MEDLINE    
CONCLUSIONS: The middle ear (ME) surface area/volume ratio (SA/V) is greater than that of the tympanum. The rate of ME pressure decrease is proportional to the ME SA/V. The mastoid air-cell system (MACS) will not function as an ME gas reserve unless the blood perfusion/surface area is much greater for the tympanum than the MACS and decreases as MACS volume increases.
OBJECTIVE: To measure the MACS and tympanum surface areas and volumes and ascertain whether the MACS could function as an ME gas reserve.
METHODS: Twenty adult subjects with a wide range of MACS volumes underwent CT of their MEs. The left and right surface areas and volumes of the tympanum and MACS were reconstructed and entered into a simple perfusion-limited model of transmucosal gas exchange. In this model the MACS would be a gas reserve if ME SA/V was less than the tympanum SA/V or equivalently, if their ratio was less than a critical value of 1.
RESULTS: Both MACS and tympanum SA were linearly related to their volumes. MACS SA/V and the ME SA/V were significantly greater than those for the tympanum. Inputting the measured values into the model yielded a critical value of 1.4, which was significantly greater than 1.
J Douglas Swarts; Brendan M Cullen Doyle; Cuneyt M Alper; William J Doyle
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural    
Journal Detail:
Title:  Acta oto-laryngologica     Volume:  130     ISSN:  1651-2251     ISO Abbreviation:  Acta Otolaryngol.     Publication Date:  2010 Nov 
Date Detail:
Created Date:  2010-10-14     Completed Date:  2011-01-27     Revised Date:  2014-09-08    
Medline Journal Info:
Nlm Unique ID:  0370354     Medline TA:  Acta Otolaryngol     Country:  England    
Other Details:
Languages:  eng     Pagination:  1230-6     Citation Subset:  IM    
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MeSH Terms
Ear, Middle / anatomy & histology,  physiology,  radiography*
Mastoid / anatomy & histology,  physiology,  radiography*
Medical History Taking
Models, Biological*
Organ Size
Radiographic Image Enhancement / methods
Reference Values
Young Adult
Grant Support

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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