Carnivore GIT Flashcards
What are the four layers of the carnivore GIT?
Mucosa, submucosa, muscularis externa, serosa/adventitia
Where does the esophagus lay in relation to the trachea?
To the left and slightly dorsal
What main nerve innervates the esophagus?
Vagus nerve
Where does the terminal esophagus drain into?
Portal system
What stimulates peristalsis?
External nerves and distension of the esophagus/stomach/intestines
What are three common sites of esophageal obstruction?
Thoracic inlet, over heart base, entrance into diaphragm
What is the vascular ring anomaly?
When a major blood vessel is malformed and constricts the esophagus, only allowing liquid through
What general organs is the carnivore digestive tract made of?
Stomach, duodenum, jejunum, ileum, cecum, ascending colon, transverse colon, descending colon, rectum, spleen, pancreas (Along with spleen are the major secretory organs of carnivore digestive tract)
What is the name of the layer of peritoneum that lines the body wall?
Parietal peritoneum
What is the name of the layer of peritoneum that lines the organs?
Visceral peritoneum, encloses organs in two folds of peritoneum
What are the peritoneal organs?
Stomach, liver, spleen, pancreas, small intestine, large intestine, bladder, reproductive
What are the retroperitoneal organs?
Kidneys, adrenal glands
What is “mesentery?”
Folds of peritoneum that enclose organs
What two mesenteric layer make up the greater mesentery?
Mesoileum and mesojejunum
What other mesenteric layers are present in the body besides greater mesentery?
Mesoduodenum, mesocolon, mesorectum, mesogastrium (Omentum)
What is the name of the sac that is created by two folds of the greater omentum?
Omental bursa
What is the name of the channel in the greater omentum that leads from the liver to the sac of the greater omentum?
Epiploic foramen
How does the digestive system get the main supply of its blood?
Dorsal aorta
Where does the majority of the blood from the liver and terminal rectum drain into?
Caudal vena cava
Where does the majority of the blood from the terminal esophagus, spleen, pancreas, and proximal rectum drain into?
Hepatic portal system to the liver
What is the only vessel that does not drain into the heart?
Hepatic portal vein, drains to liver
What are the three branches of the celiac artery?
Left gastric artery, splenic artery, hepatic artery
What three branches of the aorta supply the entire digestive tract?
Celiac artery, cranial mesenteric artery, caudal mesenteric artery
What is the ductus venosus?
A portosystemic shunt that is present when an animal is young but should close off as an adult (Sometimes does not, causes problems), causes blood to bypass the liver
Where do lymph nodes generally lie in the digestive tract?
Within the mesentery
What are the four parts of the basic non-ruminant stomach?
Cardia, fundus, body, pylorus
What is secreted by each part of the carnivore stomach?
Cardia: Mucus
Fundus/body: Acid (HCl, pepsin)
Pylorus: Mucus and endocrine cells (Gastrin)
How is the stomach attached to the rest of the body?
Greater omentum attaches to spleen, lesser omentum attaches to liver, gastrophrenic ligament attaches fundus to left crus of diaphragm (Strongest attachment)
What is gastric torsion?
When the stomach twists around the cardia and forms a “double bubble” image on radiographs (Fundus appears as big bubble, pylorus appears as small bubble), traps gas in the stomach causing severe distension and may cut off blood supply leading to necrosis, may cause vomiting
What is the major histological difference between the small and large intestines?
Villi AND crypts will be seen in small intestine, only crypts, NOT villi will be seen in the large intestine
In which part of the small intestines are folds most numerous?
Jejunum
What are the pockets at the base between villi?
Crypts of Lieberkuhn
What lies between the mucosa and submucosa of the small intestine?
Muscularis mucosae
Which two ducts open in the cranial flexure of the duodenum?
Bile duct and pancreatic duct
What is the main function of the duodenum?
Receive liquid chyme from the stomach and neutralize the gastric acid and pepsin using mucus with bicarbonate secreted from Brunner’s glands
What is the longest part of the small intestines and where is it located?
The jejunum, located in ventral abdomen in loose coils suspended by greater mesentery
What is the main site for absorption?
The jejunum
How is the ileum supported in the abdomen?
Greater mesentery and ileocecal fold
What is the name of the junction between the ileum, cecum, and large intestines?
Ileocecocolic junction
What are Peyer’s patches and where are they found?
Immunoprotective aggregations of lymphatic tissue in submucosa of ileum
What is the main function of the large intestine?
Water and salt reabsorption from feces
What are the three sections of the large intestine?
Cecum, colon, rectum
Histologically, how is the large intestine different than the small intestine?
No villi but still crypts, more goblet cells
What is the name for the orifice connecting the ileum and the colon?
Ileocolic orifice
What is the name for the orifice connecting the cecum to the colon?
Cecocolic orifice
What does the cecum look like in the cat and dog?
Comma shaped in the cat, spiral shaped in the dog
Where in the carnivore is the cecum located?
Around the second lumbar vertebra
Describe the ascending colon.
Right side of abdomen, relatively stable, located between the duodenum and mesenteric root, connected to the transverse colon through right colic flexure
Describe the transverse colon.
Runs right to left, caudal to stomach and cranial to mesenteric root, more flexible/unstable in placement than ascending colon, connects to descending colon through the left colic flexure
Describe the descending colon.
Left side of abdomen, longest part of colon, runs to the pelvic canal
Describe the rectum.
Runs through pelvic cavity, most dorsal structure in pelvic canal, supported by mesorectum, caudal rectum is retroperitoneal because serosa reflects back to become parietal peritoneum, attached to pelvic diaphragm/vagina/urethra, stores feces
What is the difference in muscle between the internal and external anal sphincters?
Internal sphincter is the narrowing of the longitudinal smooth muscle of the gut, external sphincter is striated muscle under voluntary control.
Where are the paranal sacs (Anal glands) located?
Ventrolaterally to the anus, between the internal and external anal sphincters
What is atresia?
Failure of an orifice or passage to develop or open
What is the function of the spleen?
Store blood, remove particles from circulation, destroy red blood cells, produce lymphocytes
What is the red pulp of the spleen?
Spaces between vessels, contain RBC components, reservoir of blood cells
What is the white pulp of the spleen?
Lymph nodules
What is the capsule of the spleen?
Causes the spleen to contract to expel blood, variable in size, extends trabeculae into pulp, muscular in carnivores (Less so in ruminants), contains some lymph vessels
Describe the carnivore spleen.
Flattened and elongated, in left cranial abdomen, lies adjacent to greater curvature of stomach, head of spleen is cranial to the left kidney, tail is in the ventral abdomen, vessels enter at a variety of locations.
Describe the equine spleen.
Triangular, renosplenic ligament to left kidney, vessels enter in a ridge along the length of the spleen
Describe the bovine spleen.
Flattened and elongated, lies to the left of the rumen, vessels enter through a single hilus and pass over the rumen.
How do ovine and caprine spleens differ from the bovine spleen?
More rounded and smaller
