GI Questions 1 Flashcards
Where are bile salts produced?
The liver
What is the function of the gallbladder?
To store and concentrate bile
Where are faeces formed?
The large intestine
How many salivary glands are there?
Six - three on each side
What percentage of nutrients are absorbed in the first half of the small intestine?
95%
What are the four functions of the digestive system?
Digestion, secretion, absorption, motility
Which body cavity is serosa found in?
Peritoneal
On which organs would you find glands in the submucosa?
Oesophagus and duodenum
What are the three layers of the mucosa called?
Epithelium, lamina propria and muscularis mucosae
Where would you find simple columnar epithelium?
Stomach and small and large intestine
What is another name for Meissner’s plexus?
Submucosal plexus (parasympathetic)
Which nerves lie between the circular and longitudinal muscle layers?
Myenteric (Auerbach’s) plexus
Which nerve stimulates secretion in the stomach?
Vagus nerve (X)
Which nerve inhibits motility in the small intestine?
Splanchnic nerve
Which nerve stimulates salivation?
Facial (VII) and glossopharyngeal (IX) nerves
How would salivation be affected if the vagus nerve was cut?
It wouldn’t
Which organs are supplied by the coeliac trunk?
Stomach, small intestine, pancreas, spleen and liver
Which organs are supplied by the superior mesenteric artery?
Small intestine, caecum, ascending colon and transverse colon
Which organs are supplied by the inferior mesenteric artery?
Transverse colon, descending colon, sigmoid colon and rectum
Which vessel do the coeliac trunk, superior mesenteric artery and inferior mesenteric artery originate from?
Descending (abdominal) aorta
What are the three main divisions of the coeliac trunk?
Left gastric artery, splenic artery and common hepatic artery
What is the stomach’s arterial supply? (long answer)
The coeliac trunk gives off the common hepatic artery, the splenic artery and the left gastric artery. The left gastric artery supplies the superior portion of the lesser curvature, as well as the cardia. The splenic artery gives off short gastric arteries, which supply the most superior portion of the greater curvature and the fundus. The splenic artery also gives off the left gastro-omental artery, which supplies the remainder of the superior portion of the greater curvature. The common hepatic artery also gives off the right gastro-omental artery, which supplies the inferior portion of the greater curvature. The common hepatic artery also gives off the hepatic artery, which goes on to supply the right gastric artery and in turn supplies the inferior portion of the lesser curvature.
Where would you find stratified squamous epithelium?
Mouth, oesophagus and anal canal
What is the small intestine’s arterial supply? (long answer)
The pylorus of the stomach and the first part of the duodenum are supplied by the gastroduodenal artery from the coeliac trunk. Thereafter, the small intestine is supplied by branches of the superior mesenteric artery. The distal end of the duodenum (below the opening of the bile duct) is supplied by the pancreaticoduodenal artery. Next are the intestinal arteries, which can be divided into the jejunal and ileal groups. The jejunal arteries feed the tissue of the jejunum and form a network of interconnected arches throughout the mesentery. Blood to the ileum is provided by the ileal arteries, which form several tiers of interconnected arches in the mesentery before reaching the ileum. These arches provide detours for blood to prevent interruptions to the blood flow to the intestines. The next branch of the superior mesenteric artery, the ileocolic artery, provides blood to the terminal ileum, caecum and appendix.
What is the pancreas’s arterial supply?
The pancreas is supplied by branches of the splenic artery. The head is additionally supplied by the superior and inferior pancreaticoduodenal arteries which are branches of the gastroduodenal (from the coeliac trunk) and superior mesenteric arteries respectively.
What is the caecum’s arterial supply?
Ileocolic artery (branch of SMA)
What is the liver’s arterial supply?
The liver has a unique dual blood supply:
Hepatic artery proper (25%) - supplies the non-parenchymal structures of the liver with arterial blood. It is derived from the coeliac trunk.
Hepatic portal vein (75%) - supplies the liver with partially deoxygenated blood, carrying nutrients absorbed from the small intestine. This is the dominant blood supply to the liver parenchyma and allows the liver to perform its gut-related functions, such as detoxification.
What is the transverse colon’s arterial supply?
The right two-thirds of the transverse colon are provided by the middle colic artery, a branch of the superior mesenteric artery. The left remaining third is supplied by the left colic artery, a branch of the inferior mesenteric artery.
What is the venous drainage of the pancreas?
Venous drainage of the head of the pancreas is into the superior mesenteric branches of the hepatic portal vein. The pancreatic veins draining the rest of the pancreas do so via the splenic vein.
What is the venous drainage of the stomach?
The veins of the stomach run parallel to the arteries. The prepyloric veins drain into the right gastric veins, and the right and left gastric veins drain into the hepatic portal vein. The left gastro-omental vein and the short gastric veins drain into the splenic vein, and the right gastro-omental vein drains into the superior mesenteric vein. The splenic and superior mesenteric veins are the two major tributaries of the hepatic portal vein.
Where does the splenic vein drain to?
The hepatic portal vein –> the liver
Where does the hepatic portal vein lead to?
The liver
What is the venous drainage of the liver?
Venous drainage of the liver is achieved through hepatic veins. The central veins of the hepatic lobule form collecting veins which then combine to form multiple hepatic veins. These hepatic veins then open into the inferior vena cava.
What are the four tunics of the alimentary canal called?
Mucosa, submucoas, muscularis externa and serosa/adventitia
Which features act to increase the absorptive surface area along the alimentary canal?
Stomach rugae and villi on the endothelial surface
Why does surgery on the spleen carry the risk of making the patient diabetic?
Close to the tail of the pancreas - the lienorenal ligament is formed from peritoneum and connects the spleen to the tail of the pancreas
