Editing Respiratory system (section)

==Exceptional mammals==
===Cetaceans===
{{excerpt|Cetacean|Respiration}}

===Horses===
{{Main|Respiratory system of the horse}}
Horses are [[obligate nasal breathing|obligate nasal breathers]] which means that they are different from many other mammals because they do not have the option of breathing through their mouths and must take in air through their noses. A flap of tissue called the soft palate blocks off the pharynx from the mouth (oral cavity) of the horse, except when [[swallowing]]. This helps to prevent the horse from inhaling food, but does not allow use of the mouth to breathe when in respiratory distress, a horse can only breathe through its nostrils.{{cn|date=December 2023}}

===Elephants===
The [[elephant]] is the only mammal known to have no [[pleural space]]. Instead, the [[parietal pleura|parietal]] and [[visceral pleura]] are both composed of dense [[connective tissue]] and joined to each other via loose connective tissue.<ref>{{cite journal|last=West|first=John B.|author2=Ravichandran |title=Snorkel breathing in the elephant explains the unique anatomy of its pleura|journal=Respiration Physiology|volume=126|issue=1|pages=1–8|year=1993|pmid=11311306|doi=10.1016/S0034-5687(01)00203-1}}</ref> This lack of a pleural space, along with an unusually thick [[Thoracic diaphragm|diaphragm]], are thought to be [[Evolution#Natural outcomes|evolutionary adaptations]] allowing the elephant to remain underwater for long periods while breathing through its [[Elephant#Trunk|trunk]] which emerges as a snorkel.<ref>{{cite journal
 | last = West
 | first = John B.
 | title = Why doesn't the elephant have a pleural space?
 | journal = News Physiol Sci
 | volume = 17
 | issue = 2
 | pages = 47–50
 | year = 2002
 | pmid = 11909991
 | doi=10.1152/nips.01374.2001| s2cid = 27321751
 | doi-access = free
 }}</ref>

In the elephant the lungs are attached to the diaphragm and breathing relies mainly on the diaphragm rather than the expansion of the ribcage.<ref>{{cite journal|last1=Shoshani|first1=Jeheskel|title=Understanding proboscidean evolution: a formidable task|journal=Trends in Ecology & Evolution|date=December 1998|volume=13|issue=12|pages=480–487|doi=10.1016/S0169-5347(98)01491-8|pmid=21238404|bibcode=1998TEcoE..13..480S }}</ref>