Lecture 31: Abdomen IV Equine and Ruminant Foregut Flashcards
what structure divides glandular from nonglandular region of equine stomach
margo plicatus
left side of ruminant abdominal cavity is dominated by what structure
volume of rumen
structures located on right side of ruminant abdominal cavity (3)
-midgut organs
-hindgut organs
-dorsal mesentery
flow of ingesta through ruminant stomach: general
esophagus –> rumen and reticulum –> omasum –> abomasum –> duodenum
forestomach/proventriculus components
rumen
reticulum
omasum
is ruminant forestomach glandular or nonglandular
nonglandular
what is the glandular region of the ruminant stomach
abomasum
3 glands/regions of abomasum
cardia
fundus
pylorus
function of rumen and reticulum
reduce tough ingesta by processes of microbial fermentation (that can’t be broken down with mammalian enzymes)
flow of ingesta through ruminant stomach: specific
Esophageal opening located dorsal to reticulum and enters into atrium ruminis, goes through ruminoreticular fold, through reticular groove, into reticulum, to abomasum
relative locations of reticulum, diaphragm and heart
reticulum is just caudal to thoracic cavity containing heart and diaphragm
microanatomy of rumen and reticulum: 5 layers
-stratified squamous epithelium
-lamina propria
-muscularis mucosa
-submucosa
-muscularis interna
what causes honeycomb structure of reticulum
mucosal ridges outlining cells
rumen microanatomy (2)
stratified squamous epithelium
papillated ruminal mucosa
reticulum microanatomy (3)
stratified squamous epithelium
honeycomb
mucosal lining is cornified/keratinized
omasum contractions process
squeeze ingesta from omasal canal into recesses between the laminae –> mass contraction (squeeze fluid from material), some absorption continued
which ruminant stomach region is ill suited for milk digestion
rumen
reiculo-omasal opening in newborns
-rumen in nonfunctional
-reticular fold/groove shunts milk from esophagus to abomasum
entrance to abomasum is called
omasoabomasal orifice
abomasum exit points: from ________ to __________
pylorus to duodenum
what structure controls the release of products into duodenum
torus pyloricus
development of lesser omentum
-from ventral mesogastrium
tissue running from ventral or lesser curvature of stomach
what artery supplies ruminant foregut
celiac
innervation of ruminant foregut
vagal trunks
what is the anatomical transition between foregut and midgut
duodenum
1st part of the duodenum is what end of the developing foregut
caudal
what 3 structures share a duct system for delivery of bile and pancreatic juices to duodenum
liver
gallbladder
pancreas
1st part of duodenum receives (2)
bile
pancreatic juices
where does bile duct travel
dorsally along 1st part of duodenum
how/where does duodenum receive bile
from liver/gallbladder via common bile duct
how/where does duodenum receive pancreatic juices
from pancreas via main and accessory pancreatic ducts
what happens between common bile duct and main pancreatic duct
meet and drain into duodenum at major duodenal papilla
what allows juices to enter duodenal papilla (gastric emptying)
Sphincter of papilla and contraction of muscularis externa
what do pyloric glands release (2)
-gastrin
-mucous
gastrin
peptide hormone that stimulates parietal cells and aids in gastric motility
characteristic of duodenal mucosa
prominent villi and crypts of intestinal glands
brunner’s glands: definition, function, location
-secrete alkaline mucous that lowers acidity in 1st part of duodenum (raise pH for pancreatic enzyme function and protect from stomach acids)
-only present in proximal part of duodenum
-drain in Crypts of Lieberkuln which drain between villi
what lines surface of mucosa: 1st part of duodenum
villi
where are brunner’s glands found (specific)
submucosa of proximal portion of duodenum
crypts of Lieberkuln: definition, location
-in between villi and extend to muscularis mucosa of duodenum
-short tubular glands
