Difference between revisions of "Eructation"
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m (Text replace - "Category:Alimentary System" to "Category:Alimentary System - Anatomy & Physiology") |
m (Text replace - "[[The Rumen - Anatomy & Physiology|" to "[[Rumen - Anatomy & Physiology|") |
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==Introduction== | ==Introduction== | ||
| − | Eructation is the release of gases from the stomach through the [[Oesophagus - Anatomy & Physiology|oesophagus]]. Carbon dioxide, methane, hydrogen and other volatile products are produced in the [[ | + | Eructation is the release of gases from the stomach through the [[Oesophagus - Anatomy & Physiology|oesophagus]]. Carbon dioxide, methane, hydrogen and other volatile products are produced in the [[Rumen - Anatomy & Physiology|rumen]] through the fermentaion of food by microorganisms and most of these gases are then released through eructation. |
| − | Not all the carbon dioxide produced in the [[ | + | Not all the carbon dioxide produced in the [[Rumen - Anatomy & Physiology|rumen]] is released through eructation. Some of the gas is absorbed directly over the [[Rumen - Anatomy & Physiology|rumen]] wall. |
If gas release does not occur, or gas elimination does not equal gas production a condition called [[Bloat|bloat]] will arise. | If gas release does not occur, or gas elimination does not equal gas production a condition called [[Bloat|bloat]] will arise. | ||
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*[[The Rumen - Anatomy & Physiology#Ruminoreticular contraction|Ruminal contractions]] (no reticular contribution) | *[[The Rumen - Anatomy & Physiology#Ruminoreticular contraction|Ruminal contractions]] (no reticular contribution) | ||
| − | *Before eructation can occur the cardia must be cleared of liquid ingesta as the cardia is reflexly closed on contact with the liquid [[ | + | *Before eructation can occur the cardia must be cleared of liquid ingesta as the cardia is reflexly closed on contact with the liquid [[Rumen - Anatomy & Physiology|rumen]] contents |
*Contractions start in the ventral sac and spread to the dorsal sac | *Contractions start in the ventral sac and spread to the dorsal sac | ||
| − | *Contractions spread caudally to cranially over the [[ | + | *Contractions spread caudally to cranially over the [[Rumen - Anatomy & Physiology|rumen]] |
*Ruminal gas is forced towards the cranial cardiac area where it is aspirated into the [[Oesophagus - Anatomy & Physiology|oesophagus]] | *Ruminal gas is forced towards the cranial cardiac area where it is aspirated into the [[Oesophagus - Anatomy & Physiology|oesophagus]] | ||
Revision as of 13:44, 6 September 2010
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Introduction
Eructation is the release of gases from the stomach through the oesophagus. Carbon dioxide, methane, hydrogen and other volatile products are produced in the rumen through the fermentaion of food by microorganisms and most of these gases are then released through eructation.
Not all the carbon dioxide produced in the rumen is released through eructation. Some of the gas is absorbed directly over the rumen wall.
If gas release does not occur, or gas elimination does not equal gas production a condition called bloat will arise.
Process
- Ruminal contractions (no reticular contribution)
- Before eructation can occur the cardia must be cleared of liquid ingesta as the cardia is reflexly closed on contact with the liquid rumen contents
- Contractions start in the ventral sac and spread to the dorsal sac
- Contractions spread caudally to cranially over the rumen
- Ruminal gas is forced towards the cranial cardiac area where it is aspirated into the oesophagus
- The gases are moved orally by an antiperistaltic wave passing through the relaxed pharyngoesophageal sphincter into the pharynx
- Some of the eructated gas passes to the lungs, whilst the rest is released from the oral cavity
Gas Volume
- In the dairy cow, 0.5-1 L of gas is produced per minute in the ruminoreticulum
- The exact amount of gas absorbed into the blood and lymph is unknown, but the majority is eliminated by eructation