Malnutrition & Absorption

Question 1

What is malnutrition?

Answer 1

Insufficient dietary intake to meet metabolic requirements.

Question 2

What is malabsorption?

Answer 2

A disorder of the digestive tract resulting in the inability to utilise an appropriate dietary intake.

Question 3

What are the major constituents of food?

Answer 3

Carbohydrate, protein, fat, vitamins, minerals, salt, and water.

Question 4

What is kwashiorkor?

Answer 4

A form of PEM caused predominantly by protein deficiency.

Question 5

What is marasmus?

Answer 5

A form of PEM caused by total dietary (caloric) deficiency.

Question 6

List key features of kwashiorkor.

Answer 6

Growth failure, apathy, diarrhoea, hepatomegaly, muscle wasting, oedema, anaemia, stomatitis.

Question 7

Name causes of PEM in the UK.

Answer 7

Anorexia, malignancy, infection (TB, AIDS), anorexia nervosa, neglect, elderly diet (“tea and toast”), hospitalisation, neurological disease, dysphagia, increased metabolic demand (thyrotoxicosis).

Question 8

What deficiency causes microcytic, hypochromic anaemia?

Answer 8

Iron deficiency.

Question 9

What deficiency is associated with megaloblastic anaemia and neural tube defects?

Answer 9

Folic acid deficiency.

Question 10

What deficiency leads to osteomalacia?

Answer 10

Vitamin D deficiency.

Question 11

What are symptoms of vitamin B1 (thiamine) deficiency?

Answer 11

Cardiomyopathy, encephalopathy (Wernicke’s), neuropathy.

Question 12

What deficiency causes pellagra?

Answer 12

Niacin (vitamin B3) deficiency.

Question 13

What deficiency results in coagulopathy?

Answer 13

Vitamin K deficiency.

Question 14

What deficiency causes scurvy?

Answer 14

Vitamin C deficiency.

Question 15

Name neurological symptoms of vitamin B12 deficiency.

Answer 15

Neuropathy, subacute combined degeneration (SACD), ataxia, dementia.

Question 16

What are the key structures for digestion?

Answer 16

Mouth, stomach, pancreas, biliary tract, small intestine.

Question 17

What enzymes are produced in the mouth?

Answer 17

Amylase and lipase.

Question 18

What controls stomach acid secretion?

Answer 18

Vagus nerve → Acetylcholine → Histamine → HCl from parietal cells.

Question 19

What does gastrin do in the stomach?

Answer 19

Increases acid production via positive feedback.

Question 20

How is chyme neutralized in the duodenum?

Answer 20

By enzymes raising pH from 1-2 to 6-7.

Question 21

What is the function of bile?

Answer 21

Emulsifies fats and forms micelles for absorption.

Question 22

What are the pancreatic exocrine enzymes?

Answer 22

Amylase, lipase, proteolytic enzymes.

Question 23

What happens with biliary obstruction?

Answer 23

Malabsorption of fat-soluble vitamins (ADEK), leading to coagulopathy, osteomalacia, ataxia, night blindness.

Question 24

What pancreatic diseases can cause malabsorption?

Answer 24

Chronic pancreatitis, pancreatic tumors, pancreatic duct obstruction, Zollinger-Ellison syndrome.

Question 25

Where is rapid macronutrient absorption in the small intestine?

Answer 25

Jejunum.

Question 26

What is absorbed in the ileum?

Answer 26

Bile acids, vitamin B12 (with intrinsic factor).

Question 27

What are features of enterocytes?

Answer 27

Polarised cells with apical/basolateral membranes, electrochemical gradients, specific transport pathways.

Question 28

Name luminal causes of malabsorption.

Answer 28

Infections (Giardiasis, Tb, Whipple’s), bacterial overgrowth.

Question 29

Name mucosal causes of malabsorption.

Answer 29

Crohn’s disease, coeliac disease, lymphoma, surgical resection.

Question 30

Name post-mucosal causes of malabsorption.

Answer 30

Intestinal lymphangiectasia.

Question 31

What antibodies are associated with coeliac disease?

Answer 31

Anti-tissue transglutaminase (tTG), endomysial antibodies.

Question 32

Describe histology of coeliac disease.

Answer 32

Subtotal villous atrophy, crypt hyperplasia, increased intraepithelial lymphocytes.

Question 33

What deficiencies are common in coeliac disease?

Answer 33

Iron, folate, vitamin D.

Question 34

What neurological complication can occur after terminal ileal surgery?

Answer 34

Subacute combined degeneration (due to B12 malabsorption).

Question 35

What infection causes steatorrhoea and bloating?

Answer 35

Giardiasis (G. lamblia).

Question 36

What bacteria causes subtotal villous atrophy and malabsorption?

Answer 36

Tropheryma whipplei (Whipple’s disease).

Question 37

What causes bacterial overgrowth syndrome?

Answer 37

Jejunal diverticulosis, blind loop syndrome, motility disorders, hypochlorhydria

Question 38

What are signs of vitamin A deficiency?

Answer 38

Night blindness, xerophthalmia.

Question 39

What vitamin deficiency is linked with coagulopathy in biliary obstruction?

Answer 39

Vitamin K.

Question 40

Name symptoms of protein-energy malnutrition.

Answer 40

Growth failure, apathy, diarrhoea, hepatomegaly, oedema, muscle wasting.