blind expanded portion adjacent to cardia. Often filled with gas and visible on a radiograph
layers of stomach
Lumen, mucosa, submucosa, muscle layers, serosa
Glandular or non-glandular stomachs of species
dog and cat: glandular.
Pig, horse and ruminant: composite.
Luminal surface of stomach is lined by a glandular epithelium, a nonglandular epithelium or both.
The fore-stomachs of a ruminant are non-glandular.
ridges of the lining of the stomach when it is contracted. These stretch out when the stomach is distended.
grossly visible line in body of stomach that separates the glandular/nonglandular tissue in a horse. Horses have simple composite stomachs.
3 forstomach chambers (reticulum, rumen and omasum) are nonglandular lined with stratified squamous epithelium.
The abomasum is the glandular stomach (enzymes), on the right side next to the abdominal wall.
Rumen is the fermentation vat to break down cellulose. On the left side, it displaces organs to the right.
Omasum is spherical and caudal to reticulum
consists of duodenum, jejunem and ileum. Principle digestion and absorption
Carnivores have a short gut, sheep have a LOOOONG gut
first part of the small intestine. Relatively short. Receives ingesta from stomach. Runs next to pancreas. Mesoduodenum (attached mesentery), duodenal-jejunal flexor (bridge to jejunum).
Exocrine glands: digestion enzymes
Endocrine glands: hormones.
2nd part of small intestine. Contains villi (finger-like to increase surface area) and crypts (bottom of villi, with glands). Loops, long mesentery, lots of motion.
last portion of small intestine. Indistinguishable. Empties into large intestine through ileocolic opening. Contains villi (finger-like projections to increase surface area), crypts (bottom of villi, with glands) and peyer's patches (lymph nodules)
finger-like projections that line the mucosa of the GI tract to help absorb. Increse surface area. Crypts are valleys between villi that contain glandular tissue.
non-glandular congregations of lymphoid tissue in the walls of the small intestine below villi. Prominent in ileum.
Control populations of bacteria
Layers of small intestine
Tunica serosa (outside)
Bile production and track
Made by liver, goes through hepatic ducts to cystic duct (these together are the bile duct). Stored in the gallbladder until goes down the bile duct into the duodenum through the major duodenal papilla.
Bile breaks down and absorbs fats
Bile track in equine
no gallbladder or cystic duct
constantly secreting bile through biliferous ducts into hepatic duct into duodenum.
dogs and oxen have two
cats, horses, sheep and goats have one.
Large Intestine or Colon
Dehydrates fecal contents--absorbs water. No villi, lots of lymph glands, has crypts.
Cecum (blind pouch, varies with species)
Ascending (short in varnivore, varies with species, LOOK AT DRAWING)
Transverse (right to left, oten between stomach and small intestine)
Descending (longest part. Follows left flank, then medial to rectum)
blind diverticulum at the beginning of the colon.
Cecocolon--the one opening into the colon.
Crucial fermentation center to horses. Ileum opens into cecum in horses.
Huge, comma-shaped, has a base, body and apex in the right part of the abdomen of the equine.
Blind tube extending caudally in ruminants.
Species differences in ascending colon
Carnivores: short and straight
Pig and ruminant: coil, the spiral colon
Horse: double horseshoe shaped loop (like a spiral but doubles back. HUGE. "Great colon"
Teniae and haustra
bands (teniae) that pucker to form saccules (haustra) in horses and pigs. Help tell what part of the LI you're looking at.
Not in cat and dog
retroperitoneal. From descending colon to anal canal, which is the short termination of GI. External sphincter is skeletal and voluntary.
pouches located between intermal smooth and external striated sphincter muscles of the carnivore anus. At 4 and 8 o'clock.
Blood to intestines is supplied by
cranial and caudal mesenteric arteries. Collateral circulation.
proximal duodenum uses shepatic branch of celiac artery
caudal rectum uses rectal branch of internal pudendal
Portal vein drains. Liver then systemic.
Lots of lymph, particularly in SI, drain to thoracic duct
sympathetic and parasympathetic
largest digestive gland in body. Extramural (outside lumen of GI tract). Caudate lobe encloses cranial right kidney.
Detoxification, formation and secretion of bile, digestion of carbs, protein and fat.