GI

Question 1

Regarding splanchnic nerves, where do the pre-ganglionics synapse in:
Major/minor splanchnic nerves
Lumbar splanchnic nerves

Answer 1

Major/minor splanchnic nerves: Caelico-mesenteric ganglion

Lumbar splanchnic nerves: Caudal mesenteric ganglion

Question 2

What are the 3 major arteries that branch off the aorta?

What do they supply?

Answer 2

Caeliac=cranial abdominal organs
Cranial mesenteric=mid-abdominal organs
Caudal mesenteric=caudal abdominal organs

Question 3

What are the 3 major branches that come off the caeliac artery?

Answer 3

Hepatic artery
Left gastric artery
Splenic artery

Question 4

What are the 3 major branches that come off the cranial mesenteric artery?

Answer 4

Ileo-colic artery
Caudal pancreatico-duodenal artery
Jejunal arteries

Question 5

What are the 2 major branches that come off the caudal mesenteric artery?

Answer 5

Left colic artery

Cranial rectal artery

Question 6

What is the benefit of anastomoses?

Answer 6

If an artery gets occluded, the organ will be able to receive blood via a different route

Question 7

All GI organs drain via which vessel?

Answer 7

Hepatic portal vein

Question 8

Non-GI organs drain directly where?

Answer 8

Caudal vena cava

Question 9

Which is the main branch going into the hepatic portal vein?

Answer 9

Gastro-duodenal vein

Question 10

Where does the left gastric vein drain into?

Answer 10

Splenic vein

Question 11

Where does the left testicular vein drain into?

Answer 11

Left renal vein

Question 12

Which lobe of the liver features a renal impression?

Which species doesn’t have this?

Answer 12

Caudate lobe

Pig

Question 13

In the horse large intestine, what is the purpose of the taenial bands?

Answer 13

Aid in mixing and propulsion

Question 14

Where is the satiety centre located?

Answer 14

Hypothalamus

Question 15

What is the difference between probiotics and prebiotics?

Answer 15

Probiotics = sample of normal intestinal microbes
Prebiotics = substrates that promote normal intestinal microbes

Question 16

What value should rumen pH be?

Answer 16

5.5-7

Question 17

Severe/chronic vomiting leads to loss of what?

Answer 17

HCl
Causes metabolic alkalosis
Other electrolytes lost include Na+, Cl-, K+

Question 18

Why is it advised to starve a dog/cat if they have a dietary upset disorder?

Answer 18

Reduces gastric secretions
Allows time for mucosal/enterocyte healing
24-48 hours

Question 19

How does increased dietary fat lead to diarrhoea?

Answer 19

Unabsorbed fat is modified by GI bacteria -> decreased absorption -> hypertonic lumen contents -> water loss from cells by osmosis -> diarrhoea

Question 20

What is the vomiting centre stimulated by?

Answer 20

Chemoreceptor trigger zone (via dopaminergic input)
GI tract via vagal/sympathetic afferent pathways
Vestibular apparatus via cholinergic/histaminergic afferent pathways

Question 21

Why would we want to induce vomiting?

Answer 21

If an animal has ingested something toxic
To empty stomach prior to general anaesthetic (as these induce vomiting)
Ideally want to do it within an hour of animal eating, when food is still in stomach

Question 22

How do antihistamines stop vomiting?

Answer 22

Block histaminergic and cholinergic afferent (input) pathways from vestibular organs to vomiting centre
eg promanthazine

Question 23

How do anti-cholinergics prevent vomiting?

Answer 23

Block cholinergic afferent pathways from GI tract to vomiting centre
eg propantheline

Question 24

What are laxatives/cathartics used for?

Answer 24

Relief of acute non-dietary constipation
Removal of toxic ingestants
Prevention of tenesmus (muscle spasm, feeling of constantly needing to poo)
Evacuation of bowel prior to surgery/radiography

Question 25

How do osmotic cathartics work in easing constipation/ causing diarrhoea?

Answer 25

Non-absorbable therefore osmotically retain water in intestinal lumen
Lactulose metabolised by colonic bacteria into organic acids (lactic, formic, acetic) – increase osmotic pressure

Question 26

How would you correct rehydration if the patient is vomiting?

Answer 26

Parenterally

Question 27

What is the epiploic foramen bordered by?

Answer 27

Hepatic portal vein, liver and caudal vena cava

Question 28

Which nerves make up the abdominal peripheral nervous system?

Answer 28

T13 and L1-L5