GI

Question 1

Esophageal atresia with TEF

Answer 1

Blind ending esophagus, with connection below to trachea. Polyhydramnios in utero. Neonate drool, choke, and vomit on first feeding. TEF allows air to enter stomach. Cyanosis due to layrngospasm (to avoid reflux-related aspiration)

Question 2

Duodenal atresia -

Answer 2

Failure of recanalization - dilation of stomach and proximal duodenum (DOUBLE BUBBLE). Associated with down syndrome. Bilious vomiting

Question 3

Hypertrophic Pyloric stenosis

Answer 3

Nonbilious projectile vomiting. Common in firstborn males

Metabolic alkalosis. Can be associated with exposure to macrolides

Question 4

Annular pancreas

Answer 4

Ventral pancreatic bud encircles 2nd part of duodenum - can cause duodenal narrowing and nonbilious vomiting.

Question 5

Retroperitoneal structures

Answer 5

SAD PUCKER - suprarenal, aorta and IVC, duodenum (2-4th parts), pancreas (except tail), ureters, colon (descending and ascending), kidneys, esophagus (thoracic portion), rectum (partially).

Question 6

Lymph drainage above and below pectinate line

Answer 6

Above; internal iliac

Below: superficial inguinal

Question 7

Diaphragmatic hernia

Answer 7

Abdominal structures enter thorax - maybe due to congenital defect of pleuroperitoneal membrane, or trauma. Commonly on left side (right protected by liver)
Most commonly a hiatal hernia - stomach herniated upward through esophageal hiatus of diaphragm.

Question 8

Gastrin

Answer 8

G cells (Ancrum of stomach, duodenum), increased H+ secretion, growth of gastric mucosa, gastric motility. Increased release by stomach distention, alkalinazaion, amino acids, peptides vagal stim via GRP. Increased by chronic PPi use, in atrophic gastritis, in zollinger ellison syndrome.

Question 9

VIPoma

Answer 9

Non alpha, non beta islet cell pancreatic tumour - secrets VIP. Watery diarrhoea, hypokalemia, achlorydia.
VIP increases intestinal water and electroylte secretion, relaxation of intestinal smooth muscle and sphincters.

Question 10

Zollinger Ellison Syndrome

Answer 10

Gastrinoma, increase in gastrin. Gastrin increases H+ secretion, growth of gastric mucosa, and gastric motility.

Question 11

Location of iron, folate, and B12 absorption

Answer 11

Iron: Fe2+ in duodenum
Folate: In small intestine
B12: terminal ileum along with bile salts, requires intrinsic factor (lack of IF–> pernicious anemia)

Question 12

Achalasia

Answer 12

Failure of relaxation of LES due to loss of myenteric (auerbach plexus). High LES resting P and uncoordinated or absent peristalsis. Progressive dysphasia to solids and liquids.
Dilated esophagus with distal stenosis.

Question 13

Meckel’s diverticulum

Answer 13

persistence of the vitelline duct. 2x more likely in males, 2 inches long, 2 ft from ileocecal valve, 2% of population.

Question 14

Familial Adenomatous Polyposus

Answer 14

AD mutation of APC tumour suppressor gene on chromosome 5q. 2 hit hypothesis. Thousands of polyps after puberty, always involves rectum.

Question 15

Lynch Syndrome (HNPCC).

Answer 15

AD mutation of DNA mismatch repair genes with subsequent microsatellite instability.

Question 16

Serum markers of liver pathology

Answer 16

most liver disease: ALT>AST
Alcoholic: AST>ALT
Gamma glutamate transpeptidase: increased in liver and biliary disease, but NOT bone disease.
Non alcohoholic fatty liver: ALT>AST