[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

New ref: dino respiration



Of interest:

Reconstructing the evolution of the respiratory apparatus in tetrapods 
Steven F. Perry  and Martin Sander
             
Respiratory Physiology & Neurobiology 
Volume 144, Issues 2-3, Pages 125-139 
 
Abstract
The structural type of a lung for animals that are derived from a single
ancestral group can be characterized using extant phylogenetic bracketing.
Functional morphological approximation can then be used to provide further
information on the functional attributes. Combining information from diverse
sources, plausible explanations are deduced for the respiratory apparatus of
extinct species. The air-breathing apparatus of tetrapods has its origin in
gill breathing. The lungs of the first tetrapods were probably long and
consisted of a single series of parenchyma-filled chambers, arranged along
an intrapulmonary duct. The duct gave rise to a broad central lumen in
anurans. In amniotes a cartilaginous reinforcement evolved. The septate
nature of the gas-exchange tissue (parenchyma) is recognizable in all
tetrapods except birds. Active expiration began with the origin of
transverse body wall musculature in amphibians, whereas active,
negative-pressure inspiration is seen only in amniotes. The functional
transition of trunk musculature from locomotor to respiratory is most
complete in birds. 

============================================
John R. Hutchinson
Structure & Motion Lab
Royal Veterinary College, Univ. London
Hawkshead Lane, Herts AL9 7TA, UK
phone  (+44) (0)1707-666-313
fax    (+44) (0)1707-666-371 or 652-090
mobile (+44) (0)7843-629-162
web    http://www.rvc.ac.uk/sml  and
http://www.rvc.ac.uk/Staff/jhutchinson.cfm
============================================