GI Questions 1

Question 1

Where are bile salts produced?

Answer 1

The liver

Question 2

What is the function of the gallbladder?

Answer 2

To store and concentrate bile

Question 3

Where are faeces formed?

Answer 3

The large intestine

Question 4

How many salivary glands are there?

Answer 4

Six - three on each side

Question 5

What percentage of nutrients are absorbed in the first half of the small intestine?

Answer 5

95%

Question 6

What are the four functions of the digestive system?

Answer 6

Digestion, secretion, absorption, motility

Question 7

Which body cavity is serosa found in?

Answer 7

Peritoneal

Question 8

On which organs would you find glands in the submucosa?

Answer 8

Oesophagus and duodenum

Question 9

What are the three layers of the mucosa called?

Answer 9

Epithelium, lamina propria and muscularis mucosae

Question 10

Where would you find simple columnar epithelium?

Answer 10

Stomach and small and large intestine

Question 11

What is another name for Meissner’s plexus?

Answer 11

Submucosal plexus (parasympathetic)

Question 12

Which nerves lie between the circular and longitudinal muscle layers?

Answer 12

Myenteric (Auerbach’s) plexus

Question 13

Which nerve stimulates secretion in the stomach?

Answer 13

Vagus nerve (X)

Question 14

Which nerve inhibits motility in the small intestine?

Answer 14

Splanchnic nerve

Question 15

Which nerve stimulates salivation?

Answer 15

Facial (VII) and glossopharyngeal (IX) nerves

Question 16

How would salivation be affected if the vagus nerve was cut?

Answer 16

It wouldn’t

Question 17

Which organs are supplied by the coeliac trunk?

Answer 17

Stomach, small intestine, pancreas, spleen and liver

Question 18

Which organs are supplied by the superior mesenteric artery?

Answer 18

Small intestine, caecum, ascending colon and transverse colon

Question 19

Which organs are supplied by the inferior mesenteric artery?

Answer 19

Transverse colon, descending colon, sigmoid colon and rectum

Question 20

Which vessel do the coeliac trunk, superior mesenteric artery and inferior mesenteric artery originate from?

Answer 20

Descending (abdominal) aorta

Question 21

What are the three main divisions of the coeliac trunk?

Answer 21

Left gastric artery, splenic artery and common hepatic artery

Question 22

What is the stomach’s arterial supply? (long answer)

Answer 22

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.

Question 23

Where would you find stratified squamous epithelium?

Answer 23

Mouth, oesophagus and anal canal

Question 24

What is the small intestine’s arterial supply? (long answer)

Answer 24

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.

Question 25

What is the pancreas’s arterial supply?

Answer 25

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.

Question 26

What is the caecum’s arterial supply?

Answer 26

Ileocolic artery (branch of SMA)

Question 27

What is the liver’s arterial supply?

Answer 27

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.

Question 28

What is the transverse colon’s arterial supply?

Answer 28

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.

Question 29

What is the venous drainage of the pancreas?

Answer 29

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.

Question 30

What is the venous drainage of the stomach?

Answer 30

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.

Question 31

Where does the splenic vein drain to?

Answer 31

The hepatic portal vein –> the liver

Question 32

Where does the hepatic portal vein lead to?

Answer 32

The liver

Question 33

What is the venous drainage of the liver?

Answer 33

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.

Question 34

What are the four tunics of the alimentary canal called?

Answer 34

Mucosa, submucoas, muscularis externa and serosa/adventitia

Question 35

Which features act to increase the absorptive surface area along the alimentary canal?

Answer 35

Stomach rugae and villi on the endothelial surface

Question 36

Why does surgery on the spleen carry the risk of making the patient diabetic?

Answer 36

Close to the tail of the pancreas - the lienorenal ligament is formed from peritoneum and connects the spleen to the tail of the pancreas