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THE MOVEMENTS OF THE POUCHES OF THE STOMACH OF SHEEP
Author(s) -
Phillipson A. T.
Publication year - 1939
Publication title -
quarterly journal of experimental physiology and cognate medical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0033-5541
DOI - 10.1113/expphysiol.1939.sp000817
Subject(s) - omasum , reticulum , contraction (grammar) , rumen , abomasum , anatomy , endoplasmic reticulum , biology , endocrinology , food science , biochemistry , fermentation
1. The cycle of contraction in the reticulo‐rumen sac of sheep is very regular, and occurs at intervals of 50 to 70 seconds. At times this interval is longer. 2. The reticulum has a two‐stage contraction, the second contraction being superimposed upon the first. Varying degrees of relaxation often occur between the two stages. 3. The cycle of contraction in the rumen follows the two‐stage contraction of the reticulum in a regular manner. Under certain conditions the rumen will continue to contract in an irregular manner when the contractions of the reticulum are at a standstill. 4. Either two or four contractions of the rumen occur to every two‐stage contraction of the reticulum. These contractions are alternately in the dorsal and the ventral sac. 5. Variations of these cycles occurring frequently are two contractions followed by one contraction of the rumen to two consecutive two‐stage contractions of the reticulum, and four contractions followed by two. 6. None of these cycles are absolute and all may break temporarily. 7. Changes in shape and position of the omasum can be seen radiologically. Blobs of barium, and quick‐moving trickles of barium have been seen to pass from the omasum to the abomasum. The passage of blobs occurs after a contraction of the reticulum, but the passage of the quick‐moving trickles may occur at any time. 8. The body of the abomasum is lifted upwards in an anterior direction with each contraction of the reticulum, and its contents are moved towards the pyloric antrum. This action initiates waves of peristalsis in the pyloric antrum at regular intervals. 9. Barium can be seen in the duodenum within five minutes of feeding a barium meal to a young lamb from a bottle. 10. The interval of time between the contractions of the reticulum is increased after the lamb has drunk a meal of milk from a bottle. 11. The introduction of fluid directly into the abomasum through an abomasal fistula temporarily increases the interval of time between the contractions of the reticulum; if sufficient fluid is introduced, the contractions of the reticulum are stopped for longer periods, the length of which depends upon the amount introduced. 12. The application of direct pressure inside the abomasum by inflating a balloon placed inside that organ prevents contraction of the reticulum for apparently indefinite intervals so long as the pressure is maintained. This reflex supports the theory that food passes to the omasum and abomasum during every contraction of the reticulum, and indicates that the reticulum is the chief organ concerned with the onward passage of food through the stomachs.