Ruminant Stomach (Exam 2) Flashcards
Polygastric vs monogastric
poly: 4 compartments (ruminant)
mono: 1 compartment (cat/dog/horse)
3 compartments of forestomach
rumen
reticulum
omasum
Another name for forestomach (ruminants)
proventriculus
Purpose of keratinized stratified squamous epithelium in forestomach (ruminant)
protection against ingestion of coarse vegetation
Forestomach can hold up to ____ gallons and ___ takes up lots of space in the rumen.
50-55
gas
The close relationship between the rumen and reticulum is called:
ruminoreticulum
Ruminoreticulum occupies entire (left/right) side of the abdominal cavity in ruminants along with what other structure?
left
spleen
Rumen pushes _____ to the midline or right side of the abdominal cavity.
left kidney (“hangs” but Renal A/V)
Left surface of the rumen against abdominal wall
parietal surface
Right surface of rumen contacting most intestines
visceral surface
Which rumen groove does NOT correspond to pillar? What does it correspond to?
ruminoreticular groove
ruminoreticular fold
Which rumen grooves extend dorsally and ventrally and create a circular area interiorly?
coronary grooves
_____ are on the outside of the rumen, while _____ correspond internally.
grooves
pillars
Internal thickenings of wall internal to grooves
pillars
Which pillar delineated the insula ruminis?
accessory pillar
What structures are delineated by cranial and caudal pillars of the rumen?
dorsal sac + ventral sac
What are the 2 major parts of the rumen?
dorsal sac + ventral sac
What is delineated by dorsal coronary pillars (L+R) internally and continuous with caudal pillars?
caudodorsal blind sac
“Pouch” or “space” of rumen that’s not part of the dorsal sac and develops from another out-pocketing in the embryo
atrium ruminis
Atrium ruminis is part of the rumen between what 2 structures?
dorsal sac + reticulum
Internally, the atrium ruminis is bounded by _____ of the rumen and _____.
cranial pillar
ruminoreticular fold
Term for the deep cranial end of the ventral sac of the rumen
recessus ruminis
Caudoventral blind sac is delineated by _______ and ______.
caudal pillar
ventral coronary pillars (L+R)
Term for opening of cranial sac –> reticulum
ruminoreticular ostium
Opening between dorsal + ventral sac internally (delineated by pillars)
intraruminal ostium
Projections of mucosa in rumen are ____ and are prominent where? NOT prominent where?
papillae
ventral sac + atrium ruminis
dorsal sac - “cap” of gas
Function of papillae
absorption
Function of Reticulum
pass small enough particles –> omasum
Reticulum is right against the caudal surface of ______.
diaphragm (cupula)
Reticulum is from ~__ rib –> ~__ rib.
6th –> 8th
The reticulum is caudal to what organ? Clinical significance?
heart
“hardware disease”
Which forestomach compartment has opening of the esophagus?
reticulum
Term for opening of esophagus –> stomach
cardiac ostium
Groove connecting opening of reticulum (ventral from cardiac ostium)
reticular groove
Opening from reticulum –> omasum
reticulo-omasal ostium
Clinical significance of reticulo-osmasal ostium
calf eats milk right away and non-glandular part underdeveloped
“lips” contract to get milk from omasum –> abomasum quickly
What gives the reticulum its name?
cells in tunica mucosa (reticular cells)
Reticular cells in the reticulum are delineated by larger projections of thick mucosal folds called ______.
reticular crests
Omasum is on the (right/left) and between ribs __ and __.
right
8 & 11
Omasum is very (moist/dry). Why?
dry - laminae absorb water/ions
Short groove from reticulum –> omasum w/o laminae
omasal groove
Opening where milk is shunted directly through in calves
omasoabomasal ostium
Thickened tissue at the omasoabomasal ostium
omasal pillar
Omasum have ___ layer(s) of smooth muscle in each ____.
3
laminae
____ are large folds of mucosa in the fundus/body of the abomasum.
spiral folds
What is the term for combination of reticular, omasal, and abomasal grooves?
gastric groove
What is the subtle depression on interior of lesser curvature of abomasum where spiral folds begin?
abomasal groove
Ligament of lesser omentum that attaches abomasum –> liver
hepatogastric ligament
Ligament of lesser omentum that attaches cranial part of duodenum –> liver
hepatoduodenal ligament
What is the only difference between the lesser omentum in small animals?
longer distance to get to stomach
Which groove of the rumen attaches to superficial wall of greater omentum?
left longitudinal groove
Which groove of the rumen attaches to the deep wall of the greater omentum?
right longitudinal groove
Greater omentum splits into 2 layers:
superficial + deep layers
Superficial + deep layers of greater omentum come together (ventrally/dorsally) and attach to _____.
dorsally
descending duodenum
Peritoneal cavity above reflection of greater omentum where intestines are located
supraomental recess
In ruminants, the left gastroepiploic A comes off the _____ A.
left gastric A
Right + Left Ruminal Aa come off ____ A.
splenic
______ A branches into the reticular A in the _______.
left ruminal A
ruminoreticular groove
