Malabsorption Disorders

Question 1

What are the signs and symptoms of malabsorption disorders (10):

Answer 1

Diarrhea

Steatorrhea

Wt loss

Growth retardation

HYPOalbuminemia/Edema

Anemia and bleedng tendencies (B12, iron, Vit K)

Muscle cramping (Mg, phosphorous, Vit D)

Bone deterioration (Vit D, calcium)

Bloating

Dehydration

Question 2

What systems are required for digestion and absorption (11)

Answer 2

Mechanical (chewing, trituration, peristalsis)

Enzymatic/chemical (amylase, HCl, pepsin, lactase)

Hormonal (CCK, peptide YY)

Structural (villi, microvili, intestinal length, IC valve)

Transport proteins/barrier function (GLUT, desmosomes)

Microbiome (Vitamin K, fermentation)

Lymphatic (chyme transport)

Vascular (nutrient transport, tissue oxygenation)

Metabolic (mitochondria, glycogen storage/glycolysis)

Neurologic (control center)

Electric (gastric pacemaker waves)

Question 3

Absence of brush border enzymes causes what common malabsorption disorder?

Answer 3

lactose intolerace

generalized loss also seen after infection, need to repopulate brush border

Question 4

What is absorbed in the duodenum? (3)

Answer 4

LITTLE direct absorption, except for some key minerals

IRON and CALCIUM

*important site for MEDICATION ABSORPTION

Question 5

What major components are absorbed in the jejunum? (6)

Answer 5

90% of absorption occurs in the first 10 cm of the jejunum

MACRONUTRIENTS - carbs, fats and proteins

VITAMINS - water and fat soluble

Electrolytes

Remaining TRACE MINERALS, Magnesium

Water

*alcohol*

Question 6

What major components are absorbed in the ileum? (2)

Answer 6

B12

Bile Salts

Some medications (such as imodium for diarrhea)

*can adapt to loss of jejunal absorption*

Question 7

What are the major components absorbed in the colon? (3)

Answer 7

Water

Electrolytes

*can create short chain FA*

Question 8

Name 9 classic malabsorptive disorders and ther main MOA

Answer 8

Celiac Disease - inflammation with vili loss, SIBO

Cystic Fibrosis - multifactorial

PBC / PSC - cholestasis (bile loss)

Chronic Pancreatitis - pancreatic insufficiency

Lactose Intolerance - disaccharidase loss

Short Bowel Syndrome - loss of surface area, loss of key absorptive seg (TI, colon)

Bacterial Overgrowth - ineffective bile saltas, B12 consumption/malabsorption

Amyloidosis - infiltrative with vili loss, motility, bacterial overgrowth

Scleroderma - motility, bacterial overgrowth