Enteral respiration, also referred to as cloacal respiration or intestinal respiration, is a form of

respiration Respiration may refer to: Biology * Cellular respiration, the process in which nutrients are converted into useful energy in a cell ** Anaerobic respiration, cellular respiration without oxygen ** Maintenance respiration, the amount of cellul ...

in which gas exchange occurs in the posterior cavity of the enteral system. This is used in various species as an accessory respiration mechanism in hypoxic environments as a means to supplement blood oxygen.

Turtles

Some

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked t ...

s, especially those specialized in diving, are highly reliant on

cloacal In animal anatomy, a cloaca ( ), plural cloacae ( or ), is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles and birds, a ...

during dives. They accomplish this by having a pair of accessory air bladders connected to the cloaca which can absorb oxygen from the water.

Other animals

Various

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

, as well as

polychaete Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made ...

worms and even crabs, are specialized to take advantage of the constant flow of water through the cloacal respiratory tree of

sea cucumbers Sea cucumbers are echinoderms from the class Holothuroidea (). They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. Sea cucumbers are found on the sea floor worldwide. The number of holothurian ...

while simultaneously gaining the protection of living within the sea cucumber itself. At night, many of these species emerge from the anus of the sea cucumber in search of food. The

pond loach The pond loach (''Misgurnus anguillicaudatus''), also known as the Dojo loach or oriental weatherfish, is a freshwater fish in the loach family Cobitidae. They are native to East Asia but are also popular as an aquarium fish and introduced else ...

is able to respond to the periodic drying in their native habitats by burrowing into the mud and exchanging gas through the posterior end of their alimentary canal. Studies have shown that mammals are capable of performing intestinal respiration to a limited degree in a laboratory setting. Mice were subjected to hypoxic conditions and supplied oxygen through their intestines survived an average of 18 minutes compared to 11 minutes in the control group. When the intestinal lining was abraded before oxygen was introduced, most of the animals survived for at least 50 minutes. Investigations are planned regarding the effectiveness of the strategy, the safety of this application of perfluorocarbons, and the feasibility of application to humans.

References

{{Reflist Respiration Animal anatomy Digestive system

Turtles

Other animals

See also

References