Canine GI Tract Flashcards
How does the GI tract process food?
Ingestion- prehension, mastication, deglutition (swallowing)
Absorption- compaction and peristalsis
Digestion- mechanical and chemical
Excretion- defecation
What is the digestive tract?
A tube from the mouth to the anus
Alimentary tract and accessory organs
Alimentary tract
Oral cavity
Pharynx
Esophagus
Stomach
Large intestine
Small intestine
Accessory organs
Teeth
Tongue
Salivary glands
Liver
Gallbladder
Pancreas
Where is the esophagus commonly obstructed?
Thoracic inlet
Base of the heart
Esophageal hiatus of the diaphragm
What is the function of the stomach?
Store food for churning and move chyme to the small intestine
Stomach position when it’s empty
Left side of the abdomen
Stomach position when it’s fully filled
Moved caudally contracting ventral body wall
Where are the cardia, fundus and body located?
Left of the midline
Angular notch
Indentation on the concave lesser curvature of the stomach
Pylorus
Sphincteric termination of the stomach
Right of the mid-line
Joins body to the descending duodenum
3 parts: pyloric antrum, p. canal and p. sphincter
Relatively fixed
Stomach in a healthy dog
Non-palpable but freely movable
Interior of the stomach
Gastric mucosa made of cardiac (mucous), proper gastric (pepsin and HCL) and pyloric (mucous)
Rugae (empty mucosa and submucosa are thrown into folds)
Gastric Dilatation Volvulus
Occurs within 2 hours of eating
Dilation occurs with accumulation of gas, fluid and food within the stomach
What breeds is GDV most common in?
Most common in large deep chested dogs like great danes and german shepherd
What are the clinical signs of GDV?
Abdominal distention
Restlessness
Abdominal pain
Attempts to vomit (retching)
Hypersalivation
How does GDV affect the pyloris?
Pylorus rotates 90-360 degree clockwise direction from right to left over the fundus and body
What happens to the stomach with GDV?
Distended stomach compresses the cd. vena cava and portal vein to reduce the venous return to heart
Gastric contents ferments and stomach dilates
Attempts to vomit, usually unsuccessful
How is the duodenum affected by GDV?
Duodenum becomes trapped between distal esophagus and stomach
What are the affects of GDV?
Decreased cardiac output
Hypolemic shock and metabolic acidosis
Hypotension and tissue hypoxia
Liver can’t clear gram neg endotoxins–> endotoxemia
What are the treatments of GDV?
IVFs
Gastric decompression (orogastric tube)
Gastrocentesis (18 gauge needle, right side of the abdomen)
Small intestine
Major digestive organ and main site for absorption
Divided into duodenum, jejunum and ileum
How is the surface area of the small intestine increased?
Plicae cicularis (villi and microvilli)
Duodenum parts
Cr. duodenal flexure (r. side of midline)
Descending duodenum (r. side of midline)
Cd. duodenal flexure (near pelvic midline)
Duodenojejunal flexure
Mesoduodenum
Attaches the duodenum to abdominal roof/ abdominal wall
What is the function of the duodenum?
Enzymatic digestion and absorption
What are the lobes of the liver?
R. and l. medial
R. and l. lateral
Quadrate lobe
Caudate lobe- caudate and papillary process
Quadrate lobe
Between right and left medial lobes
Contact the gall bladder
Caudate lobe
Caudate process- renal impression of right kidney
Papillary process- lies along lesser curvature of stomach
Gall bladder
Temporary storage of bile
Located beween r. medial and quadrate lobes
Hepatic duct and cystic duct
Hepatic duct and cystic duct
Drains lobes into gall bladder
Inactive digestion
Common bile duct
Formed by union of cystic and hepatic ducts
Opens on major duodenal pailla
One duct in cats (80%)