COMPARATIVE ANATOMY - Ruminant Digestive System Flashcards
Are ruminants foregut or hindgut fermenters?
Foregut fermenters
Which side of the abdominal cavity is predominately taken up by the ruminant stomach?
Left side of the abdominal cavity
What is the only organ other than the stomach that is located on the left side of the ruminant abdominal cavity?
Spleen
What are the four chambers of the ruminant stomach?
Reticulum
Rumen
Omasum
Abomasum
Which chambers of the ruminant stomach are known as the fore-stomach?
Reticulum
Rumen
Omasum
What is the collective name for the reticulum and the rumen?
Ruminoreticular unit
Which structure seperates the reticulum and the rumen?
Ruminoreticular fold
What is the reticular groove?
The reticular groove is fleshy lips of smooth mucosa that run from the oesophageal entry and through the reticulum to the reticulo-omasal orifice
What is the function of the reticular groove in unweaned animals?
In unweaned animals, suckling stimulates the closure of the reticular groove to form a tube which directs the ingested milk directly to the omasum and into the abomasum, bypassing the ruminoreticular unit. This prevents the fermentation of the milk which is essential for the neonate to gain maximum nutrition from the milk
What can be administered to stimulate the closure of the reticular groove to allow veterinary drugs to pass directly into the omasum and abomasum?
Copper sulphate
What are the four sacs within the rumen?
Dorsal sac
Ventral sac
Caudodorsal sac
Caudoventral sac
Which structures subdivide the rumen into a dorsal and ventral sac?
Ruminal pillars
Which structures subdivide the rumen into a caudodorsal and caudoventral sac?
Coronary pillars
Where within the dorsal sac does ingesta enter the rumen?
Ingesta enters the dorsal sac of the rumen via the atrium ruminis
Where is the opening to the omasum located within the ruminant stomach?
The reticulum opens into the omasum at the reticulo-omasal orifice
Where does the omasal canal run within the ruminant stomach?
The omasal canal runs from the reticulo-omasal orifice to the omaso-abomasal orifice
What is the function of the omasal canal?
The omasal canal transports ingesta from the reticulum through the omasum and into the abomasum
What is the difference in the shape of the omasum in cattle and sheep?
Cattle: rounded omasum
Sheep: bean shaped omasum
Which is the only glandular chamber of the ruminant stomach?
Abomasum
What is the largest stomach chamber in neonatal ruminants?
Abomasum
Which artery supplies the ruminant stomach?
Coeliac artery
Which nerve innervates the ruminant stomach?
Vagus nerve
Describe the locations of the greater and lesser omentum within the ruminant abdominal cavity
Greater omentum: extends from the greater curvature of the abomasum to the duodenum
Lesser omentum: extends from the lesser curvature of the abomasum to the hilus/porta hepatis of the liver
At which side of the abdomen are the ruminant intestines located?
The right side of the abdominal cavity
What is the widest part of the ruminant intestine?
Caecum
Describe the appearance of the ruminant ascending colon
The ruminant ascending colon forms a sigmoid flexure when it exits the ileocaecocolic junction followed by a double spiral shape
How many loops of the ascending colon are usually seen in cattle?
Two ascending colon loops
How many loops of the ascending colon are usually seen in sheep?
Three or four ascending colon loops
At which side of the abdominal cavity is the liver found in the ruminant?
The right side of the abdominal cavity
What are the four liver lobes found in the ruminant?
Left lobe
Quadrate lobe
Right lobe
Caudate lobe
What are there three structures which suspend the liver in the ruminant abdominal cavity?
Triangular ligaments
Round ligament
Lesser omentum
Where is the ruminant gallbladder located?
Between the quadrate and right liver lobes
What is the difference between the pancreatic duct in large and small ruminants?
In large ruminants, the pancreatic duct empties directly into the duodenum whereas in small ruminants, the pancreatic duct combines with the common/terminal bile duct and empties into the duodenum
