Lecture 20 4/3/24 Flashcards
What are the four compartments of the bovine stomach, and how are they oriented?
-reticulum: cranial
-rumen: left
-omasum: right
-abomasum: right and ventral
What are the characteristics of the reticulum?
-located between diaphragm and rumen
-on midline in 6-9th intercostal spaces
-dorsally continuous with cranial sac of rumen
Which structure ventrally separates the reticulum from the cranial sac of the rumen?
rumenoreticular groove
What are the characteristics of the rumen?
-large and laterally flattened
-extends from diaphragm to pelvic inlet
-fills left half of abdominal cavity
-caudoventral part can extend to right of midline
What is the left side of the rumen associated with?
-left abdominal wall
-floor of abdominal cavity
-diaphragm
What is the right side of the rumen associated with?
-intestines
-liver
-omasum
-abomasum
What is the dorsal curvature of the rumen associated with?
-diaphragm
-roof of abdominal cavity
What is the ventral curvature of the rumen associated with?
floor of abdominal cavity
Which grooves divide the rumen?
-left and right longitudinal grooves
-cranial and caudal grooves
-dorsal and ventral coronary grooves
What do the cranial and caudal grooves divide the rumen into?
dorsal and ventral sacs
What do the dorsal and ventral coronary grooves form?
caudodorsal and caudoventral blind sacs
What are the characteristics of the cranial sac?
-projects cranially from dorsal sac
-known as ruminal atrium
What are the characteristics of the ruminal recess?
projects cranially from the ventral sac
What is housed within the ruminal grooves?
-vessels
-nerves
-lymphatics
-lymph nodes
What are the characteristics of the omasum?
-spherical
-lies ventrally between ventral sac of rumen and right abdominal wall
-contacts right abdominal wall in intercostal spaces 6-11
-larger than reticulum in bovine; smaller in sheep and goat
What are the characteristics of the abomasum?
-resembles simple stomach of the canine
-divided into cardiac, fundic, body, and pyloric parts
-greater and lesser curvatures
What are the branches of the celiac a.?
-splenic a.
-left gastric a.
-hepatic a.
Which arteries branch off of the splenic a.?
-right ruminal a.
-left ruminal a.
-reticular a.
What are the characteristics of the inside of the reticulum?
-aglandular
-crests that form cells in a honeycomb structure
-small papillae
-lined with cornified, stratified squamous epithleium
How does the reticulum communicate with the cranial sac of the rumen?
rumenoreticular orifice
Which structure separates the reticulum from the cranial sac of the rumen?
rumenoreticular fold
What are the characteristics of the inside of the rumen?
-aglandular
-tongue-shaped papillae
-lined with cornified, stratified squamous epithelium
-dorsal and ventral sacs separated by pillars
Which pillars are present within the rumen?
-right and left longitudinal pillars
-cranial and caudal pillars
-dorsal and ventral coronary pillars
How does the dorsal sac of the rumen communicate with the ventral sac?
intraruminal opening
What are the characteristics of the inside of the omasum?
-aglandular
-lined with cornified, stratified squamous epithelium
-filled with lamina; increased SA for water absorption
Which region of the omasum lacks lamina?
omasal canal
How does the omasum communicate with the abomasum?
omasal-abomasal orifice
What are the characteristics of the inside of the abomasum?
-glandular
-mucosa has permanent spiral folds
-ruminants and pigs lack a good pyloric sphincter
Which region of the abomasum lacks permanent spiral folds?
abomasal groove
What do ruminants and pigs have in place of a pyloric sphincter?
torus pyloricus
What is the gastric groove?
channel from the reticulum to the pylorus
What are the divisions of the gastric groove?
-reticular groove
-omasal groove
-abomasal groove
What is the function of the gastric groove?
shunt milk from esophagus to abomasum
