Gastro-Intestinal Tract Flashcards
What branches of the spinal cord of the peripheral nervous system supply the abdominal organs?
T13
L1-3
What does the dorsal and ventral branch of the peripheral nervous system supply?
Dorsal- dorsal abdominal skin
Ventral- splits medial, lateral and lateral cutaneous
What do the three parts of the ventral branch of the peripheral nervous system supply?
Medial- runs between transverse abdominus and internal abdominal oblique- supplies TA, IAO, RA and ventral abdominal skin
Lateral- perforates internal abdominal oblique and runs between IAO and external abdominal oblique- supply IAO and EAO
Lateral cutaneous- perforates external abdominal oblique supplying lateral skin
What are the differences between the sympathetic nervous system and parasympathetic nervous system?
Sympathetic fight or flight, suspend digestion, ganglia as site of synapses, long post ganglionic
Parasympathetic- homeostasis, promote digestion, plexus- no synapses until reach organ of innervation, short post ganglionic
What two types of nerves from the sympathetic nervous system supply the GI?
Major/minor splanchnic nerves
Lumbar splanchnic nerves
Where do the major and minor splanchnic nerves synapse and where do the lumbar splanchnic nerves synapse?
Major/minor- caeliaco-mesenteric ganglia
Lumbar- caudal mesenteric ganglion
What two nerves parasympathetically supply the GI?
Vagus and Pelvic
How does the vagus supply the abdominal organs?
Splits as it enters abdomen and reunites to form:
Dorsal vagal trunk- visceral surface of stomach/ pylorus
Ventral vagal trunk- parietal surface of stomach/ pylorus and liver
Continues to calico-mesenteric plexus and follows arteries to rest of organs
Where does the pelvic nerve emerge from the spinal cord and where does it pass through before the organs?
S1-S3
Passes through pelvic plexus then follows arteries to pelvic organs
What arteries supply the abdominal wall?
Cranial abdominal
Deep external iliac
Cranial epigastric
Caudal epigastric
What do each of the abdominal wall arteries supply?
Cranial abdominal- cranio-dorso-lateral
Deep external iliac- caudo-dorsal-lateral
Cranial epigastric- cranio-ventero-lateral
Caudal epigastric- caudo-ventero-lateral
What are the three major branches off the aorta which supply the abdominal organs?
Caeliac- cranial abdominal organs
Cranial mesenteric- mid-abdominal
Caudal mesenteric- caudal abdominal organs
What are the three branches of the caeliac artery?
Hepatic
Left gastric
Splenic
What are the three branches of the hepatic artery?
Hepatic branches
Right gastric
Gastroduodenal
What does each of the three hepatic artery branches supply?
Hepatic branches- liver, cystic artery to gall bladder
Right gastric- right lesser curvature of stomach
Gastroduodenal- right gastro-epiploic artery to right greater curvature of stomach, cranial pancreatico-duodenal artery (cranial lobe of pancreas/duodenum)
What does the left gastric artery supply?
Left lesser curvature of the stomach
Oesophageal branches to oesophagus
What does the splenic artery supply?
Short gastric arteries- greater curvature of stomach
Pancreatic branches- left lobe of pancreas
Left gastro-epiploic- left greater curvature of stomach
What are the three branches of the cranial mesenteric artery?
Ileo-colic artery
Caudal pancreatico-duodenal artery
Jejunal arteries
What do the caudal pancreatico-duodenal artery and jejunal arteries supply
Pancreatico-duodenal artery- caudal right lobe of pancreas and duodenum
Jejunal arteries- jejunum
What are the 5 branches of the ileo-colic artery and what do they supply?
Middle colic artery- transverse colon Right colic artery- right colic flexure Colic branch of ileo-colic- ascending colon Caecal branch of ileo-colic- caecum Mesenteric ileal- ileum
What are the two branches of the caudal mesenteric arteries and what to they supply?
Left colic artery- left colic flexure/descending colon
Cranial rectal artery- cranial rectum
What other abdominal organs are there that don’t supply GI organs?
Left and right renal arteries
Left and right ovarian/testicular arteries
What is an anastomoses?
Safety mechanism for if an artery gets occluded the organ will continue to receive blood
Where are anatomises present in the GI artery tract?
Left/right gastric Left/right gastro-epipoloic Cranial/caudal pancreatico-duodenal Middle/right colic Middle/left colic Colic branch of ileo-colic/right colic Mesenteric ileal/jejunal jejunal/jejunal
How do all GI organs drain venously?
Hepatic portal vein to vena cava
Where do veins differ to arteries supplying/draining GI organs?
No celiac vein
Cranial/caudal mesenteric are terminal veins of hepatic portal vein
How does ruminants blood supply to stomach vary compared to all other species?
Rumino-reticulum and greater curvature of abomasum- left/right gastro-epiploid. Rather then greater curvature
Omasum/lesser curvature of abomasum- left/right gastric. Rather then lesser curvature
How does the caecum blood supply of dogs, ruminants, horses and pigs vary?
Dog/ruminants- small caecum- caecal branch of ileo-colic, anti-mesenteric ileal branch of ileum
Horse/Pig- large caecum- medial caecal, lateral caecal- no anti-mesenteric
What arteries are all the same in species supplying the colon?
Proximal ascending- colic branch of ileocolic
Distal ascending- right colic
Transverse- middle colic
Descending- left colic
What arteries are different in species supplying the colon?
Colic branch of ileocolic in horses supplies ventral colon, pigs and ruminants- centripetal coils
Right colic horse- dorsal colon, pigs/ruminants- centrifugal coils
How does the omentum vary between horse, pig and dog?
Horse and Pig are similar to dog
Horses doesn’t extend back to cover intestinal mass
In which species is the peritoneum most and least developed?
Least developed in a horse
Most developed in ruminants
Describe the structure of a ruminants omentum?
Superficial wall attaches to rumen on the left
Deep wall attaches to rumen on right
Space between is mental bursa
How do species livers differ in situ?
Pig straight like dog/cat
Horse- oblique (right lobe dorsal, left more ventral)
Ruminant= 90 degrees
How does the structure of the liver vary between species?
Ruminants- caudate lobe larger in ox, papillary lobe larger in sheep
Horse- no papillary lobe, no gall bladder
Pig/dog/cat- left and right lobes sub-divided
What are the different lobes of the liver?
Left lobe Right Lobe Quadrate Lobe Caudate Lobe Papillary lobe
How do different species spleen vary in shape?
Horse- comma shaped Ox tongue shaped Sheep oval Pig elongated- bright red Dog hockey stick shaped
Which species liver doesn’t have a caudate process with a renal impression?
Pig
Which species have both a pancreatic and accessory duct, just pancreatic and just accessory?
Both- horse and dog
Just pancreatic- sheep/goat
Just accessory- ox/pig
What is different about a pigs stomach compared to a dog?
Gastric diverticulum (increased secretion of mucous)
Large cardiac gland region
Prominence of lymphatic tissue
Torus pyloricus
How does the small intestine differ between species?
Similar
Pig jejunum- LI pushes most to right
Thickened ileum in a horse
How does the large intestine differ between pigs and ruminants?
Pigs- Caecum on left, colon in spiral loop
Ruminants- colon in coiled loop
Describe the structure of a horses large intestine?
Large caecum
right ventral, sternal flexure, left ventral, pelvic flexure, left dorsal, diaphragmatic flexure, right dorsal, transverse, descending colon
What aids mixing and propulsion in the horses LI?
Sacculated and taenial bands
How many taenial bands do each part of a horses large intestine have?
Caecum- 4 RVC- 4 LVC- 4 LDC- 1 RDC- 3 Transverse- 2 Small- 2
How does a horses blood supply differ to a dogs?
Caecum- lateral and medial caecal vessels
Ventral colon- colic branch of ileocolic
Dorsal colon- right colic
No anti-mesenteric ileal supply
How does a pigs blood supply differ to a dogs?
Left gastric artery- branch of splenic
proximal centripetal coils- colic branch of ileocolic
distal centrifugal coils- right colic
How do ruminants blood supply differ to dogs?
Omasum/lesser curvature of abomasum derived from lesser curvature of embryonic stomach- supplied by left/right gastric
ruminoreticulum/greater curvature of abomasum derived from greater curvature of embryonic stomach- supplies by left/right gastroepiploic and short gastric branches of splenic
Centripetal coils- colic branch of ileocolic
Centrifugal coils- right colic
Describe a ruminants topographical anatomy?
Left side- ruminoreticulum
Right side- colon, jejunum, omasum/abomasum, liver
Describe a pigs topographical anatomy?
Left side- caecum, colon
Right side- jejunum
Describe a horses topographical anatomy?
Left- jejunum and small colon, left colon
Right- caecum, right colon, most of liver
What is a rectal examination used for in both horses and ruminants?
To examine reproductive tract
Other then reproductive tract what is rectal examination used for in horses?
To examine digestive tract
What can be palpated in a horses rectum and in what area (left dorsal/ventral, right dorsal/ventral)?
Left dorsal- jejunum/small colon- taenial bands
Left ventral- pelvic flexure
Right dorsal- base of caecum
Right ventral- body of caecum
