Iron metabolism, absorption of nutrients

Question 1

Role of Hepcidin and ferroportin in regulating systemic iron absorption

Answer 1

Ferroportin stimulates iron release from enterocyte into the bloodstream

Hepcidin inhibits iron release from enterocyte into bloodstream.

Question 2

Sites of absorption of iron in Gut

Answer 2

Duodenum

Question 3

Site of absorption of B12 and bile acids

Answer 3

Terminal ileum

Question 4

Site of absorption of water and lipids

Answer 4

Throughout small intestine

Question 5

Diagnostic features of Wilsons disease

Answer 5

AR inheritance, defect in ATP7B involved in copper excretion

• High 24 hr urine copper
• Low serum copper and ceruloplasmin
• KF rings on ophthalmoscope
• Liver biopsy with measurement of copper

Rx- Zn and trientine

Question 6

Liberation of dietary cobalamine from R proteins most likely to be affected by which condition

Answer 6

Pancreatic insufficiency

Question 7

Mechanisms for production of endogenous glucose

Answer 7

Glycogenolysis in liver and kidney
Gluconeogenesis from lactate and alanine
Activation of lipolysis

Question 8

Site of secretion of gut hormones

Answer 8

Gastrin from G cells
CCK from I cells
Secretin from S cells
Somatostatin from D cells

Question 9

HLA in coeliac disease

Answer 9

HLA DQ2, DQ8 -Associated with 99.6%pts with coeliac

Question 10

Low levels of Vitamin B12 least likely in

Answer 10

Transcobalamine II deficiency

Question 11

Intraluminal digestion of dietary starch by salivary and pancreatic amylase leads to which disaccharide

Answer 11

Maltose

Question 12

Biochemical indicator of B12 deficiency

Answer 12

High MMA, homocysteine