Small intestine

Question 1

root of mesentery

Answer 1

starts from the duodenojejunal flexure, left to L2 vertebra and runs diagonally to the sacroiliac joint to the right

Question 2

motor/parasympathetic/sympathetic supply of small intestine

Answer 2

motor and parasympathetic - vagus ( preganglionic synapse with the intrinsic neural plexus in the wall)
sympathetic - superior mesenteric ganglion ( T9/10)

Question 3

difference between jejunum and ileum in
a) wall
b)valvulae conniventes
c) arterial arcades
d) percentage of smallbowel

Answer 3

a) thick – thin
b) large —-small
c) simple and long vessels —- multiple and short terminal vessels
d) 40%—-60%

Question 4

Peters patches are present in ?

Answer 4

submucosa of small intestine and are more prominent in terminal ileum

Question 5

the two nerve plexus in SI?

Answer 5

Meissners plexus present in the submucosa
myenteric plexus sandwiched between the outer longitudinal and inner circular muscle layers of muscularis propria

Question 6

transverse folds in SI

Answer 6

valvulae conniventes / plica semilunari / valves of kecking

Question 7

length of SI

Answer 7

3-10 metres

Question 8

water secretion and output rate of small intestine

Answer 8

secretes approx 10L/ day
normal output -500ml /day

Question 9

absorption of —— in small intestine
1) vitamin b12
2) folic acid
3) iron

Answer 9

1) terminal ileum – vitamin b12-intrinsic factor complex
2) jejunum
3) if reduced to fe+2 then absorbed in SI and then transported back to blood stream as fe+3

Question 10

what happens after jejunal resection to water / folic acid absorption?

Answer 10

water reabsorption is reduced resulting in diarrhoea until ileum adapts to increase it absorptive capacity

but folic acid absorption may fail to recover and thus may have to be supplemented

Question 11

what happens after resection of terminal ileum for more than 1 metre

Answer 11

1) vitamin b12 absorption is reduced and results in megaloblastic anaemia unless supplemented
2)absorption of bile salts is reduced resulting in malabsorption of fats and fat soluble vitamins and increased risk of gallstones

Question 12

what is the anti-epileptic drug that inhibits the mucosal enzyme system and results in folic acid deficiency ?

Answer 12

EPANUTIN

Question 13

choledochoduodenal fistula

Answer 13

between cystic duct/gb and duodenum resulting in gallstone ileus

Question 14

factors that inhibit spontaneous healing of fistula

Answer 14

distal obstruction, persistent underlying disease, epithelisation of the fistula tract, presence of foreign body, malnutrition, loss of bowel continuity

Question 15

management of fistulas SNAP

Answer 15

Sepsis - treat accordingly
Nutrition - oral intake to be reduced to reduce the output from fistulas, IVF should be encouraged and TPN is best given via central line– monitoring input and output and electrolytes
Anatomy- fistulography using contrast, barium studies, US, CT, injected dye and biochemistry of the output
Plan - conservative management likely to heal spontaneously

Question 16

drugs used to reduce secretions

Answer 16

somatostatin, H2 receptor antagonists, PPI’s

Question 17

benign tumours of small bowel

Answer 17

Peutz-jeghers hamartomas, adenoma, GI stromal tumour( GIST) — have malignant potential
lipoma, fibromas, schwannoma, lymphangiona, hemangioma, neurilemmomma

Question 18

Primary malignant tumours of SI

Answer 18

duodenum - adenocarcinoma( 40%), carcinoid 25%, lymphoma and sarcoma
rest - carcinoid 31%, adenocarcinoma, lymphoma and sarcoma

Question 19

Peutz-Jeghers syndrome

Answer 19

1) melanin spots around lips, buccal mucosa and sometimes face and extremities
2) numerous hamartomatous polyps throughout the bowel (more in jejunum and rest of small bowel)

HARAMARTOMA- abnormal growth of normal tissue

Question 20

whipples procedure for ampullary tumours

Answer 20

resection of gallbladder, pylorus of stomach, duodenum, pancreas and anastomosis of gastrojejunostomy and pancreaticojejunostomy and choledochojejunostomy

Question 21

gastrointestinal stromal tumours ( GIST)

Answer 21

• malignant potential/ spindle cell neoplasms— mostly in stomach and duodenum
• KIT-CD117 positive tumours
• asymptomatic as they grow extraluminal and not cause obstruction/ bleeding, perforation and invasion
• NICE treatment - IMATINIB treatment for unresectable tumours, else resection with cuff of normal tissue

Question 22

CARCINOID tumours

Answer 22

• terminal ileum, appendix, rectum
• neuroendocrine tumours secreting neuroendocrine substances
• seretonin secretion causes intense desmoplastic reaction

Question 23

CARCINOID SYNDROME

Answer 23

• if carcinoid tumours starts secreting vasoactive substances and mets to liver
• secretions such as serotonins
  -metabolised in liver and excreted as 5 -Hydroxyindolacetic acid ( 5-HIAA)
  -symptoms : flushing, diarhhoea, bronchospasm
  -CT, enema, urinary 5-HIAA raised
• <1cm - local excision
  >2cm- small bowel resection and anastomosis with lymphatic clearance
• palliative liver/bowel resection, chemo, subcutaneous octroetide
• excellent prognosis of early and no mets, 5 year survival is 30%

Question 24

Lymphoma commonly associated with

Answer 24

coeliac disease and immune-compromised patients

Question 25

peripheral lymphadenopathy , haematological abnormality and hepatosplenomegaly indicates that the lymphoma in smallbowel is ? Primary/secondary

Answer 25

SECONDARY

Question 26

drug induced GI ulcers

Answer 26

potassium supplements, NSAIDs

Question 27

risk of mesenteric angiography for GI bleeding

Answer 27

transmural ischemia and perforation , when used with embolisation or injection of vasoconstrictor

Question 28

SMA embolic occlusion typically lodge at ?— sparing which part of small bowel ?

Answer 28

branch of middle colic artery - sparing jejunum( supplied by small jejunal arteries that branch proximal to middle colic artery)