Malabsorption and Small Intestinal Disease Flashcards Preview

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Flashcards in Malabsorption and Small Intestinal Disease Deck (42)
1

What are the functions of the small intestine?

Digestion: Breaking of food into its components

Absorption: Passage of nutrients into the body

Endocrine and neuronal control functions: Controlling the flow of material from the stomach to the colon

Barrier functions: Maintaining a barrier against pathogens

2

How does the small intestine maintain a barrier against pathogens?

Immune sampling

Monitoring the presence of pathogens

Translocation of Bacteria

Gut Associated Lymphoid Tissue (GALT)

3

What is Gut Associated Lymphoid Tissue?

The intestines contain the largest accumulation of lymphoid tissues in the body in the form of lymphoid aggregates in Peyer's patches and in the lamina propria.

This all makes up the GALT

4

Why must the GALT be careful in its battle against pathogens?

It must react to the bad pathogens (e.g. typhoid) but it can't over react and attack the food we eat.

5

How long is the small intestine and what is the limit of this length for it still to function?

Average length 2.5-4.5m
(achieved by 11 yrs)

Can still function effectively with only 1.5m

6

How does the small intestine maintain its low bacterial population?

Creates a toxic environment:
-Digestive enzymes
-Bile salts
-Presence of IgA etc

Motility:
-Constantly moving stuff on and cleaning itself
-Motility problems can lead to bacterial growth

7

Despite the small intestines fantastic ability to remain relatively sterile what organism can live?

Giardia Lamblia
-Unicellular parasite
-Contaminated water
-Responds to Metronidazole
-Hypogammaglobulinaemia
-Actually needs bile to survive

8

Why in digestion does the final hydrolysis usually occur at the brush border?

Absorption can immediately follow the full digestion to prevent osmotic shifts.

9

What are the symptoms of small intestinal disease?

Weight loss
Increase Appetite
Steatorrhoea

10

What is steatorrhoea?

A form of diarrhoea

Fat malabsorption
High fat content in stool
Stool less dense and floats
Pale
Foul smelling
may leave an oily mark

11

What are the signs of small intestinal disease?

Signs of weight loss
Low or falling BMI

12

What are the most common nutrients to be malabsorbed?

Iron, B12 and Folate

13

What vitamins could you see a deficiency in with someone who presents with steatorrhoea?

Vitamin D (Tetany, Osteomalacia)
Vitamin A (Night blindness)
Vitamin K (Raised PTR, problems with haemodynamics)

14

What signs might you see in someone with a Thiamine (Vit B2) deficiency and how much should you give to replace this if they are ill?

Loss of short term memory
Dementia

It isn't known how much thiamine you require when you are ill but it is a lot.
If you are in any doubt about a deficiency replace

15

What is the other name of Vitamin B3?

Niacin

Deficiency can cause dermatitis and unexplained heart failure

16

What can a lack of vitamin C cause?

Scurvy

17

Name 3 non-specific Signs of specific illness that affects the small intestine

Clubbing: Coeliac Disease, Crohn's

Scleroderma: Systemic Sclerosis

Aphthous Ulceration: Coeliac, Crohn's

18

What is scleroderma?

Autoimmune disease causing hardening of the skin.

In the more severe form it affects internal organs = Systemic sclerosis

19

what is aphthous ulceration?

Repeated formation of benign and non-contagious mouth ulcers

20

What is Dermatitis Herpetiformis?

Cutaneous manifestation of coeliac disease

Blistering
Intensely Itchy
Scalp, Shoulders, Elbows, Knees
IgA deposit in skin

Very unusual but VERY itchy

21

What are the tests you can use to assess the structure of the small intestine?

Small bowel biopsy
Small bowel study
White cell scan
CT scan
MRI enterography
Capsule enterography

22

How can you test for bacterial overgrowth in the small intestine?

H2 Breath Test:
-Lactulose or Glucose substrate
-Broken down to form marked hydrogen
-Not terribly accurate

culture a duodenal or jejunal aspirate

23

When carrying out a test of an antibody subset what must you do in addition?
e.g. when testing for Anti TTG

Do a test to check if they can produce the antibody in the first place

E.g. Anti Tissue Transglutaminase (Anti-TTG) IgA
-Afterwards do a test for IgA to see if the person can actually produce it (no adverse effect if not)

24

How do you confirm Coeliac disease?

Distal Duodenal Biopsy.
-Looking for Villous atrophy

Serology
-Anti endomysial IgA
-Anti Tissue Transglutaminase
---Both 95% specific and sensitive

25

What is villous atrophy?

Villi of the intestine have shrunk.
Lots of crypts

The life time of the enterocyte in coeliac disease is greatly reduced so that villi can't actually form

26

What is Coeliac Disease?

The most common malabsorption disease.

Sensitivity to Gliadin which is a fraction of Gluten.

27

What foods in Gliadin found?

Gluten is found in Wheat, Rye and Barley.

Absent from rice and maize.

Not found in oats but most oat products are contaminated with wheat

28

What is the pathology of Coeliac Disease?

Produces and inflammatory response
-This is thought to be via tissue transglutaminase (which can be tested)

Partial or subtotal villous atrophy (may cause iron deficiency also)

Increased intra-epithelial lymphocytes

Gold standard diagnosis is still a distal duodenal biopsy

29

In addition to Anti Endomysial IgA and Anti TTG what other test can be useful for diagnosing Coeliac in children?

Anti Gliadin

May help in children but not diagnostic in adults

30

What is the treatment for Coeliac disease and why is it absolutely fucking shit?

Withdraw Gluten

Problem is that:
-Wheat is used widely in commercial food (GOUJONS)
-Diet is life long

GET THAT SON BITCH A DIETITION

31

Name some of the conditions associated with Coeliac disease

Dermatitis Herpetiformis
IDDM
Autoimmune thyroid disease
Autoimmune hepatitis
Primary Biliary cirrhosis
Autoimmune gastritis
IgA deficiency
Downs Syndrome

32

What is IDDM?

Insulin Dependent Diabetes Mellitus

aka Type 1 diabetes

33

What are the complications of Coeliac Disease?

Refractory coeliac disease
Small bowel lymphoma
Oesophageal carcinoma
Colon Cancer
Small bowel adenocarcinoma

34

What is refractory Coeliac disease?

Patient doesn't respond to diet.
Some patients are massively sensitive and so cross contamination is a huge issue

35

What are the inflammatory causes of malabsorption?

Coeliac Disease
Crohn's

36

What are the infective causes of malabsorption?

Tropical sprue
HIV
Giardia Lamblia
Whipples Disease

37

What is tropical sprue?

-Folate deficiency
-Very like coeliac but will respond to antibiotics
-Keep an eye out for risk areas

38

What is Whipples disease?

Middle aged men
Skin, brain, joints and cardiac effects
Weight loss
Malabsorption
Abdominal pain
PAS material villi

Tropheryma whippelii is the causative organism

39

What are the impaired motility diseases that may cause impaired motility?

Systemic sclerosis
Diabetes
Pseudo obstruction

40

What are the iatrogenic causes of malabsorption?

Gastric surgery
Short bowel syndrome
Radiation

41

What are the pancreatic causes of malabsorption?

Chronic pancreatitis
Cystic fibrosis

42

What are the two important points to pick out of a history when you suspect malabsorption?

Weight loss
Steatorrhoea