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===Digestion===
The digestive response of Burmese pythons to such large prey has made them a model species for digestive physiology. Its sit-and-wait hunting style is characterized by long fasting periods in between meals, with Burmese pythons typically feeding every month or two, but sometimes fasting for as long as 18 months.<ref name=":04"/> As digestive tissues are energetically costly to maintain, they are downregulated during fasting periods to conserve energy when they are not in use.'''<ref name=":22">{{cite journal |vauthors=Starck JM, Beese K |title=Structural flexibility of the intestine of Burmese python in response to feeding |journal=The Journal of Experimental Biology |volume=204 |issue=Pt 2 |pages=325–335 |date=January 2001 |doi=10.1242/jeb.204.2.325 |pmid=11136618 |url=https://jeb.biologists.org/content/204/2/325}}</ref>''' A fasting python has a reduced stomach volume and acidity, reduced intestinal mass, and a 'normal' heart volume. After ingesting prey, the entire digestive system undergoes a massive re-modelling, with rapid hypertrophy of the intestines, production of stomach acid, and a 40% increase in mass of the ventricle of the heart to fuel the digestive process.<ref>{{cite journal|url=http://jeb.biologists.org/cgi/reprint/211/24/3767?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&author1=secor&andorexacttitle=and&andorexacttitleabs=and&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT |title=Digestive physiology of the Burmese python: broad regulation of integrated performance |publisher=Jeb.biologists.org |date=2008-12-15 |doi=10.1242/jeb.023754 |access-date=9 August 2012|last1=Secor |first1=Stephen M. |journal=Journal of Experimental Biology |volume=211 |issue=24 |pages=3767–3774 |pmid=19043049 |s2cid=5545174 |doi-access=free }}</ref> During digestion, the snake's oxygen consumption rises drastically as well, increasing with meal size by 17 to 40 times its resting rate.<ref name=":04"/> This dramatic increase is a result of the energetic cost of restarting many aspects of the digestive system, from rebuilding the stomach and small intestine to producing [[hydrochloric acid]] to be secreted in the stomach. Hydrochloric acid production is a significant component of the energetic cost of digestion, as digesting whole prey items requires the animal to be broken down without the use of teeth, either for chewing or tearing into smaller pieces. To compensate, once food has been ingested, Burmese pythons begin producing large amounts of acid to make the stomach acidic enough to turn the food into a semi-liquid that can be passed through to the small intestine and undergo the rest of the digestive process.
The energy cost is highest in the first few days after eating when these regenerative processes are most active, meaning Burmese pythons rely on existing food energy storage to digest a new meal.<ref name=":04" /><ref name=":3">{{cite journal |vauthors=Secor SM |title=Gastric function and its contribution to the postprandial metabolic response of the Burmese python Python molurus |journal=The Journal of Experimental Biology |volume=206 |issue=Pt 10 |pages=1621–1630 |date=May 2003 |pmid=12682094 |doi=10.1242/jeb.00300 |doi-access=free}}</ref> Overall, the entire digestive process from food intake to defecation lasts 8–14 days.<ref name=":22"/>
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